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  1. 7th/8th Review Project Collection

  2. LO 1.29. The student is able to describe the reasons for revisions of scientific hypotheses of the origin of life on Earth. • SP 6.3.The student can articulate the reasons that scientific explanations and theories are • refined or replaced. • Explanation. Science is constantly changing. We are continually gaining knowledge about life on Earth, partly due to the development of new technologies. Experimental investigations allow us to learn about the origin of life on earth. With the help of previous learned knowledge and current technologies, more details and information can be gathered about life on Earth and how life came to be. Conclusions can be drawn from looking at historical evidence and past experiments, as well as current findings and explorations. Because more and more information is found by scientific research everyday, revisions to hypotheses are often made because previous hypotheses are proven to be incorrect or in need of “revisions.”In scientific research, making a hypothesis is an important step before performing an experiment or conducting research because it addresses the purpose of the experiment and helps the student to apply current knowledge and the historical background of the claim with future expectations. • MC Question • Hypotheses are made before every science exploration or experiment. As time progresses and science advances, more knowledge about the origin of life on Earth becomes known. With more knowledge available, scientific hypotheses are revised over time because some information is proven false, inconclusive, or just not as detailed as it could be. There are always new improvements with science. Listed below are 4 scientific hypotheses about the origin of life on earth. Which of the following represents a possible hypothesis of the origin of life using up-to-date and current knowledge • A)Life on Earth originated at photosynthetically-active porous structures, similar to deep-sea hydrothermal vents, made of zinc sulfide (more commonly known as phosphor). • B)Prions were a first model for life on earth. • C)The early Earth had a reducing atmosphere, which meant it had large amounts of hydrogen and almost no oxygen. • D)RNA alone triggered the rise of life from a sea of molecules. • E)Parasites are the model for ‘first life’ • Free Response Question • Suppose you live in the era where Earth’s atmosphere was thought to be made up of just oxygen. Describe how you would revise this hypothesis with knowledge of the 21st Century. What makes this hypothesis so outdated? Support with an example of an important gas found in the atmosphere and it’s purpose in life. Why are theories and hypotheses constantly changing in our world? References http://undsci.berkeley.edu/article/0_0_0/howscienceworks_06 http://echo2.epfl.ch/VICAIRE/mod_2/chapt_3/main.htm http://www.cawcr.gov.au/projects/climatechange/challengesCoasts.shtml

  3. MC Question Answer/Explanation A)It is argued that under the high pressure of a carbon-dioxide-dominated atmosphere, zinc sulfide structures could form on the surface of the first continents, where they had access to sunlight. This is an updated hypothesis. You can tell because new knowledge about certain chemicals and gases is incorporated and applied to the origin of life hypothesis. B) Prions were not one of the first models on earth because they can only ‘replicate’ by causing proteins made by a cell to become misshaped C) An oxygen-poor atmosphere would have resulted in an atmosphere full of carbon monoxide, noxious methane, hydrogen sulfide, and ammonia, making life on earth difficult and ‘deadly’. D)RNA is a very complex molecule that is unlikely to have arisen prebiotically. Also, RNA is also considered inherently unstable. E)A parasite can not be one of the first life models because in order for a parasite to survive, it needs another cell. Free Response Answer Suppose you live in the era where Earth’s atmosphere was thought to be made up of just oxygen. Describe how you would revise this hypothesis with knowledge of the 21st Century. What makes this hypothesis so outdated? Support with an example of an important gas found in the atmosphere and it’s purpose in life. Why are theories and hypotheses constantly changing in our world? The earth’s atmosphere is now known to have many key components. The atmosphere is made up of 79% Nitrogen, 20% oxygen and 1% of other gases. If there was no nitrogen(also considered a buffer gas), then the atmosphere would be made up of only oxygen and that would cause combustible material on earth to explode from even a tiny spark. Living organisms also require nitrogen, which is an essential component of proteins and nucleic acids, for example. This hypothesis must be revised to say that the earth’s atmosphere is made up of more than just oxygen, but also other key elements necessary for life, such as nitrogen. The old hypothesis is outdated because the information is incorrect and relatively vague. Today, we have so much more knowledge of different elements and gases and how they interact in the circle of life. Theories and hypotheses are constantly changing because new information and knowledge is discovered every day. Some new information proves previous hypotheses/theories incorrect, other new information may not be entirely incorrect, but more developed from improvements in technology and have greater details and proof.

  4. LO 3.48: The student is able to create a visual representation to describe how nervous systems detect external and internal signals. SP 1.1: The student can create representation and models of natural or man-made phenomena and systems in the domain. Explanation: The neuron is the basic unit in the nervous system. A labeled model of a neuron is shown in an image below. The dendrites bring the signal, whether it’s external or internal, toward the cell body. From the cell body, the signal travels down the axon while the myelin sheath insulates the axon. This is done through an action potential when the sodium channels allow enough sodium into the neuron where it becomes -55mV and a nerve impulse is fired. The neuron must re-polarize itself by opening the potassium channels to regulate the cell back to -70mV. The cell remains at a constant -70mV with the help of the Na+/K+ pumps that use ATP to make sure the concentration is the same on both sides of the membrane. The impulse then travels down the axon until it reaches the synapse. The voltage-gated ion channels open to allow calcium to make the neurotransmitters cross the synaptic cleft and bind to the receptor on the postsynaptic cell. It will allow sodium to come in or potassium to leave and then the channels will close. M.C. Question: Which of the following happens when the action potential reaches the terminus of the pre-synaptic cell? A) The ligand-gated ion channels open B) Allow potassium to leave the cell C) It depolarizes the cell D) The voltage-gated calcium channels open Learning Log/ FRQ-Style Question: Explain what happens when the doctor taps your knee and causes your lower leg to jerk and start swinging. (CUES: reflexes, quads, sensory neurons, brain, spinal chord, motor neurons)

  5. Answer Key- LO 3.48 M.C. Question: Which of the following happens when the action potential reaches the terminus of the pre-synaptic cell? A) The ligand-gated ion channels open B) Allow potassium to leave the cell C) It depolarizes the cell D) The voltage-gated calcium channels open Explain what happens when the doctor taps your knee and causes your lower leg to jerk and start swinging. (CUES: reflexes, quads, sensory neurons, brain, spinal chord, motor neurons) When the doctors hits your knee, sensors detect a stretch in your quad muscle which makes sensory neurons send a signal to your spinal chord. The signal is split to influence the motor neurons. Therefore when the sensory neurons contracts the quad the motor neurons make the hamstring relax. Even though there are many different processes going on the signal never ends up reaching the brain. This is why there is a reflex when your doctor hits you in the correct place on the knee.

  6. Learning Objective 4.7: The student is able to refine representations to illustrate how interactions between external stimuli and gene expression result in specialization of cells, tissues, and organs. Science Practice 1.3: The student can refine representations and models of natural or man-made phenomena and systems in the domain. Statement: Cells specialize their function and structure through the stimulation and repression of coding DNA sequences by regulatory proteins. Regulatory proteins are coded from regulatory genes, any sequence of DNA that codes for regulator proteins or RNA. Regulatory proteins can be activated by external stimuli such as temperature or nutrient levels in the cytoplasm, increasing or decreasing the rate of prevalence for a protein that is transcribed by a particular gene sequence as the genes has other regulatory proteins bound or unbound to it in response to the stimuli. During the process of specialization, the external environment of a cell has an important effect on the development on that cell. Ligands produced by other cells bind with membrane bound receptors to activate signal transduction pathways and cause cellular responses through induction. These cellular reaction generating molecules also exist in the cell that is being affected, with their presence creating a cycle of development as the proteins their genes code for elicit more responses in conjunction with external molecules in order to specialize the cell. Specialization is the changing of function and structure of a cell for the greatest efficiency in a performing a particular task in conjunction with other cells to form a specific type of tissue. As an example of the effect of environmental stimuli on specialization, take into account a pair of identical twins. Since the twins are identical, they share the same genes. If, however, one of the twins was several inches taller with noticeably darker skin tone and as such exhibited a difference in phenotype despite having the same genes. Both of these traits would be caused by an environmental stimulus or condition that affected gene expression rather than solely being affected by the cell’s internal environment. For specific cellular specialization, neurons could be taken for an example. Neurons are structurally adapted for sending electrical impulses and for communication, being elongated with numerous dendrites and axon terminals for multiple connections to other neurons. Their interior chemical environment is different, specialized for sodium and potassium flow for action potentials to be sent. Other factors http://www.biologyjunction.com/images/whatis.jpg

  7. Review Questions This muscular tissue, a collection of muscle cells, does not resemble the typical image of a cell presented by the media. Name two advantages muscle cells have by having this structure. In addition, name an internal adaptation that muscle cells to more effectively perform their task. Induction is the process of cells sending signals into their environment to affect the development of nearby cells through signal transduction pathways. What is true about this process? • Signals produced by neighboring cells suppress transcription of regulatory genes during development. • Signals produced by neighboring cells stimulate transcription of regulatory genes during development. • Signals produced by neighboring cells either promote or suppress transcription of regulatory genes during development. • Signals produced by neighboring cells create positive feedback loops to influence their own development. http://medicalpicturesinfo.com/muscle-cell/

  8. Answer key This muscular tissue, a collection of muscle cells, does not resemble the typical image of a cell presented by the media. Describe two advantages muscle cells have by having this structure. In addition, name an internal adaptation that muscle cells to more effectively perform their task and describe how it improves function. The elongated design of muscle cells allows for the extended contraction and extension of muscles, and are lengthy to reach across the extent of bones so that they are able to pull them. Muscle fibers are thick and are able to endure more stress than other cells and are comparatively more difficult to damage because they have to regularly move. Muscle cells have increased concentrations of mitochondria within their cytoplasm to compensate for their high levels of energy use, they must produce ATP in larger amounts in order to function. Induction is the process of cells sending signals into their environment to affect the development of nearby cells through signal transduction pathways. What is true about this process? A. Signals produced by neighboring cells suppress transcription of regulatory genes during development. B. Signals produced by neighboring cells stimulate transcription of regulatory genes during development. C. Signals produced by neighboring cells either promote or suppress transcription of regulatory genes during development. D. Signals produced by neighboring cells create positive feedback loops to influence their own development

  9. LO 3.11 The student is able to evaluate evidence provided by data sets to support the claim that heritable information is passes from one generation to another generation through mitosis, or meiosis followed by fertilization. SP 5.3 The student can evaluate the evidence provided by data sets in relation to a particular scientific question. Explanation:The transmission of genetic information is passed from one generation to the next through sexual reproduction. Genetic variation is the result of sexual reproduction because new combinations of genetic information are created, due to the activity of chromosomes during meiosis. Genetic material is divided during nuclear division either through the process of mitosis or meiosis. Meiosis, a reduction division, produces haploid gametes that are each genetically different from the parent cell and each other. These haploid cells produced are gametes. When the gametes fuse together fertilization occurs. This then gives rise to a diploid cell known as the zygote. The zygote will then divide by mitosis in order to produce a multicellular organism. Multiple Choice Question:Which of the following statement (s) are false concerning the inheritance of genetic information via mitosis?A) The daughter cell chromosomes are identical to the parent cell B) The daughter cells of mitosis are haploidC) The daughter cells of mitosis are diploidD) Variation of inherited material is introduced via crossing in mitosis Learning Log Question: Normal human somatic cells contain 46 chromosomes. One set of 23 is derived from the mother, while the other set is from the father. A) After a cell undergoes mitosis, how many chromosomes will the cell contain? B) After meiosis takes place, how many cells will be produced and how many chromosomes will they contain? C) How is genetic variation attained through sexual reproduction via fertilization?

  10. Answer Key- LO 3.11 Which of the following statement (s) are false concerning the inheritance of genetic information via mitosis?A) The daughter cell chromosomes are identical to the parent cell B) The daughter cells of mitosis are haploidC) The daughter cells of mitosis are diploidD) Variation of inherited material is introduced via crossing in mitosis Learning Log Question: Normal human somatic cells contain 46 chromosomes. One set of 23 is derived from the mother, while the other set is from the father. A) After a cell undergoes mitosis, how many chromosomes will the cell contain? B) After meiosis takes place, how many cells will be produced and how many chromosomes will they contain? C) How is genetic variation attained through sexual reproduction via fertilization? Answers: • The cell will contain 46 chromosomes because two genetically identical cells are produced. • Four daughter cells are produced, containing half as many chromosomes as the parent cell. Therefore, 23 chromosomes are in these gametes. • During meiosis crossing over can occur. Crossing over is when homologous chromatids exchange genetic information. Also, the random nature of fertilization only increases the genetic variation. For an example, each female and male gamete represents one out of approximately 8 million chromosome combinations.

  11. LO:4.1: The student is able to create a representation that describes how organisms exchange information in response to internal changes and external cues, and which can result in changes in behavior. Explanation:For example, plants communicate and exchange information through the release of chemicals. The roots exchange gases with the air spaces of soil, then take in oxygen and discharging CO2, while cellular respiration breaks down sugars. Information in response to internal changes and external cues are detected by receptors at first. If the plant does not receive enough light, or photosynthesis, the plant will respond negatively. Without light or water the plant would slowly shrivel up, but if the shoot reaches sunlight, it will begin to green, or de-etiolation. This relationship is extremely important for the plants survival. SP:1.1 The student can create representations and models of natural or man-made phenomena and systems in the domain. M.C. Question:Which of the following statements concerning Photosystem II is false? A) During the electron transport chain 2NADP+ to 2NADPH is not reduced. B) Uses light energy to oxidize two molecules of water into one molecule of molecular oxygen. C) Absorbs photons of a wavelength of 680 nm D) During the electron transport process a proton gradient is generated across the thylakoid membrane. Learning Log/FRQ-style Question: List 2 examples of stimuli that plants react to and then describe the process that occurs in great detail.

  12. Answer Key- LO 3.41 Which of the following statements concerning Photosystem II is false? A) During the electron transport chain 2NADP+ to 2NADPH is not reduced. B) Uses light energy to oxidize two molecules of water into one molecule of molecular oxygen. C) Absorbs photons of a wavelength of 680 nm D) During the electron transport process a proton gradient is generated across the thylakoid membrane Explanation: The correct answer is A because the 4 electrons removed from the water molecules are transferred by an electron transport chain to reduce 2NADP+ to 2NADPH. List 2 examples of stimuli that plants react to and then describe the process that occurs in great detail. One example of a stimuli that plants react to is Hydrotropism, which is the plant’s response to water. When hydrotropism occurs the roots can grow towards water (positive) or the shoots can grow away from water (negative). Auxins, a plant hormone is what correlates this growth. They play a huge role is the bending of the plants. Another example is Phototropism, which is a plants response to light. Light is very important for the survival of plants, and photosynthesis take place in the chloroplast of plants. The chemical equation for photosynthesis is CO2 + H2O + light energy ------> C6H12O6 + O2 + energy. Once photosynthesis takes place, carbon dioxide is converted into organic compounds, which are then used for the reproduction and growth of plants. http://www.plant-and-flower-guide.com/phototropism.html

  13. SP 7.1: The student can connect phenomena and models across spatial and temporal scales Explanation: Apoptosis is the body sending a signal to a cell, causing the cell to die. The formation of digits is determined by this programmed cell death of the interdigital regions between the digits. Separation of the cartilaginous condensations which are to become digits depend on the death of the mesenchymal cells that are in between these cells . This allows the adjacent cells to differentiate into the specific , individual digit or finger on the hand rather than be connected by webbing. This is why early developing fetuses have webbing between their fingers. When the cell undergoes apoptosis a specific enzyme will break down the proteins, organelles, and DNA. These parts are digested by vesicles and reused as building blocks for new cells. Apoptosis plays a vital role in the maintaining homeostasis as if it occurs too much or too little can lead to cancer or disease. For example if the DNA of a cell is damaged and cannot be repaired the cell must perform apoptosis or risk the defect being replicated and spread to other cells. MC Question: Which of the following will trigger a cell major caspase activation pathway causing apoptosis? A-cAMP B- cytocines C- cytochrome C D- apoptase FR Question: What medical problems could arise from the disruption of programmed cell death? Explain why these problems would occur? LO 2.34: The student is able to describe the role of programmed cell death in development and differentiation, the reuse of molecules, and the maintenance of dynamic homeostasis.

  14. Answer Key- LO 2.34 MC Question: Which of the following will trigger a cell major caspase activation pathway causing apoptosis? A-cAMP B- cytokines C- cytochrome C D- apoptase What medical problems could arise from the disruption of programmed cell death? Explain why these problems would occur? Some problems associated with disruption in programmed cell death are cancer, ALS, and huntington’s disease. Cancer can occur if programmed cell death does not occur as frequently as it should. This is because a cell, which has a defect of some sort that should undergo apoptosis, does not and passes the defect as it replicates leading to a collection of defective tissues or cancer. ALS and Huntington’s disease can occur from programmed cell death occuring more frequently than it should. Healthy cells are given the signal for apoptosis and degrade themselves. This can destroy healthy neurological pathways leading to a loss of functionality in an individual.

  15. LO 4.25: The student is able to use evidence to justify a claim that a variety of phenotypic responses to a single environmental factor can result from different genotypes within the population. SP 6.1: The student can justify claims with evidence. Explanation: A populations ability to respond to one environmental factor differently is occurring because of genetic variation within the population. Populations that are not able to have genetic variations are in danger of becoming extinct. Some examples of populations that didn’t have genetic diversity are the California Condor, the Black-footed Ferret, and Prairie Chickens. A very successful population that has genetic variation is the population of different finches on the Galapagos Islands that Darwin studied. The different birds adapted by growing different beaks for the different food sources so they wouldn’t compete for food. Also in some disease outbreaks within a population, individuals are affected differently because of their different genetic makeup. Some have major symptoms or even death, while others in the same population may experience nothing. All variations within a population can be modeled by the Hardy-Weinberg equation: p^2+2pq+q^2=1. The P^2 represents all the individuals within a population that have homozygous dominant alleles for the trait. The 2pq represents all the individuals within a population that have heterozygous alleles for the trait. The Q^2 represents all the individuals within a population that have the homozygous recessive alleles for the trait. This equation can also be represented in a punnett square which looks like the figure to the right. The hereditary tree to the right shows how traits are passed down from generation. Multiple Choice Question: Which of the following are results of genetic variation based on different environmental factors? I. Natural Selection II. The creation of antibiotic resistant pathogens III. Two offspring of homozygous dominant parents for all alleles mating to make their own babies IV. An Alaskan fox being able to change its coat color during seasonal change A) I & 2 only B) III only C) All of the above D) I, II, IV Free Response Question: The Nazca Booby is a type of bird that is indigenous to the western parts of South America but more recently they have started to inhabit one of the islands of the Galapagos. Because the island the Boobies inhabit have no natural predators they have become more accustomed to people being around them. Name a few different phenotypic responses that the Booby could display while it is laying on its eggs and a human is approaching them for a stress test. Justify your answer with evidence from other animal species.

  16. Multiple Choice: The answer to the multiple choice question is D). This is because natural selection, the creation of antibiotic resistant pathogens and an Arctic Fox being able to change its coat color during the different seasons are all examples of genetic variation in response to different environmental factor. Natural selection will favor the animal that has the best genetics for its environment, like finches in the Galapagos changing their beak style so they wont compete for food. With antibiotic resistant pathogens the pathogen that isn’t effected by the drug will survive and reproduce to live on. Lastly the Arctic Fox is able to change its coat color because during the winter its environment is snowy and white so it needs a white coat for camouflage to hunt and in the warmer months its environment is brown so it changes its coat color to brown to camouflage itself during warmer months. Free Response: Since the Booby has been isolated for so long from natural predators the humans could have multiple effects on them. I believe the most common response to someone stressing out the bird on their nesting site would be to become territorial and try to attack the person. This is displayed in multiple animal like the lioness for instance when she is protecting her territory. The bird may also have no idea what to do and just sit there because it has never encountered something like this before. You can see this when dear stop in the middle of the road in oncoming traffic because they are just so frightened they have no idea what to do. A third response could be that the Booby would just turn around and pretend that the person isn’t there. A perfect quote can display this, “out of sight, out of mind.” These are three different phenotypic responses that a population of Booby could have to the same environmental factor. Answers

  17. Citations • http://www.google.com/imgres?imgurl=&imgrefurl=http%3A%2F%2Fbiology.westfield.ma.edu%2FBiol203%2Fpopulation-genetics-outline&h=0&w=0&tbnid=m8pIe-HRxZf29M&zoom=1&tbnh=109&tbnw=143&docid=BqfPGbH2OZZA3M&tbm=isch&ei=dq1hU8DFFLSksQS22IHgAg&ved=0CAgQsCUoAg • https://www.google.com/search?q=hardy+weinberg+equation&safe=off&tbm=isch&tbo=u&source=univ&sa=X&ei=RKxhU7e7JfTQsQT57YCgDg&ved=0CEoQsAQ&biw=1366&bih=685#q=genetic+variation+within+a+population&safe=off&tbm=isch&facrc=_&imgdii=_&imgrc=6_gppozc91-43M%253A%3Bkhqikx1KRVBpkM%3Bhttp%253A%252F%252Fevolution.berkeley.edu%252Fevolibrary%252Fimages%252Fnews%252Fpantheralleles.gif%3Bhttp%253A%252F%252Fevolution.berkeley.edu%252Fevolibrary%252Fnews%252F101201_panthers%3B487%3B274

  18. LO 2.5: The student is able to construct explanations of the mechanisms and structural features of cells that allow organisms to capture, store or use free energy. SP 6.2: The student can construct explanations of phenomena based on evidence produced through scientific practices. Explanation: Free energy measures the portion of a system’s energy that can perform work when temperature and pressures are uniform throughout the system. Autotrophs capture free energy from the environment. Photosynthetic organisms capture free energy from sunlight. During photosynthesis chlorophylls absorb free energy from light which boast electrons to a higher energy level in photosystems I and II. Light energy is harnessed in photosystem here photons of light energy strike a chlorophyll molecule and excite electrons to a higher energy level. The thylakoid membrane is populated by photosystem I and photosystem II. When electrons are transferred between molecules in a sequence of reaction as they pass through the ETC a gradient of hydrogen protons across the thylakoid membrane is established. The ETC uses chemiosmosis to power ATP synthesize to make ATP; the special chlorophyll hits it again sending an electron to a higher energy level where it is captured by a different primary electron receptor. The electrons are passed along a shorted ETC and are transferred to NADP+ to create NADPH which is used in the Calvin Cycle. The Calvin Cycle occurs in the stroma of the chloroplast and releases NADP+ and ADP which is used in light reactions. Heterotrophs capture free energy present in carbon compounds produced by other organisms. Cellular Respiration is a set of process that makes energy for cells. The first step is glycolysis which means the splitting of sugar and it rearranges the bonds in glucose molecules which takes ADP and makes ATP and then the end product is pyruvate. Pyruvate is then transported across the mitochondria membrane by active transport for the Krebs cycle. In the Krebs cycle carbon dioxide is released from organic intermediates and ATP is synthesized from ADP and phosphate thorough substrate phosphorylation and electrons are captured by coenzymes. In the cycle it spins twice for each glucose molecule and one for each pyruvate molecule. NADH and FADH2 carry electrons to the electron transport chain. The ECT is in the mitochondria during cellular respiration and during photosynthesis it occurs in the chloroplasts. In cellular respiration electrons are passed to electrons acceptors as they move down the chain the final electrons acceptor is oxygen and in photosynthesis the final acceptor is NADP+.As the ETC accepts and then donate electrons they pump hydrogen ions form the mitochondrial matrix into the intermembrane space or in plants into the thylakoid membrane . Chemical energy is transformed into a proton motive force a gradient of H+ across the membrane. The hydrogen ions flow back down their gradient through a channel in an ATP synthase. The ATP synthase harnesses the proton motive force to phosphorylate ADP forming ATP. The use of a H+ gradient to transfer energy from redox reactions to cellular chemiosmosis. Together electron transport and chemiosmosis compose oxidative phosphorylation. All of these processes make free energy for organisms to use and expend in the environment.

  19. MC Question: Tom has never had any energy to do the things he needs to do throughout the day. He is taken to the doctor for some test and they discover that his mitochondria produces more lactate than the average person. What is the best explanation for his problem? • He does not have the transport protein that transports pyruvate across his mitochondria • His mitochondria is unable to perform cellular respiration • His body can not make pyruvate in glycolysis • He can not make ATP in his mitochondria • FRQ: A same plant species was observed in tow different lakes. The amount of oxygen dissolved was recorded through out the day. Using the graph and the data chart below and on the next slide compare the oxygen consumed in each lake and predict why there was a difference between the plants in each lake.

  20. Data Time Lake 1 O2 consumption Lake 2 O2 consumption 6AM (0) .5 mg .9 mg 8AM (1) 3.0 mg 2.2 mg 10PM (2) 4.6 mg 3.4 mg 12PM (3) 5.7 mg 4.8 mg 2PM (4) 7.2 mg 6.4 mg 4PM (5) 8.0 mg 7.0 mg 6PM (6) 7.1 mg 6.2 mg 8PM (7) 6.2 mg 5.3 mg 10PM (8) 4.5 mg 3.1 mg 12AM (9) 2.5 mg 2 mg

  21. Answers M.C :A. He does not have the transport protein that transports pyruvate across his mitochondria A is the correct answer because since he produces so much lactate it is converted back to pyruvate but he does not have the transport protein that moves the pyruvate into the mitochondria to continue through cellular respiration in the citric acid cycle. Therefore his body does not produce ATP that gives him energy which explains why he is tired. Free Response: Overall lake number 1 consumed more oxygen that lake 2. As the time went on in the day the oxygen consumption increased then reached its highest point in the afternoon. Then as the time passed the oxygen consumption decreased. The reason why both increased was because the sun was rising and it was getting hotter in the day as the sun set the oxygen consumption decreased. A reason why the plants in lake 1 has a higher oxygen consumption could be because it is exposed to more sunlight than lake 2. Which allows the plants in lake 1 to go thorough more photosynthesis which would explain why it has a higher oxygen consumption. http://legacy.owensboro.kctcs.edu/gcaplan/bio/notes/BIO%20Notes%20E%20Photosynthesis.htm

  22. LO 3.37 The student is able to justify claims based on scientific evidence that changes in signal transduction pathways can alter cellular response. SP 6.1 The student can justify claims with evidence. Explanation: A signal transduction pathway takes place during cell communication. Cells communicate by using neurotransmitters for short distances and hormones for long distances. The three stages of cell signaling include reception, transduction, and response. Reception is when a signal molecule (ligand) binds to the receptor protein on the outside of a target cell. Next, transduction (a series of events involving secondary messengers) occurs as the binding of the ligand causes a change in the receptor protein, which then brings about a specific cellular response. If there is a change in the signal transduction pathway, this can ultimately alter the cellular response, as the pathway in which the message is being carried along and amplified, controls whether or not the response occurs. Transduction occurs as a series of events, but it can also occur as a series of unfortunate events. Examples based on scientific evidence where pathways may be interrupted or altered include drugs, poisons, or diseases in the body. Poisons, such as those found in anthrax can cause a disruption in signal transduction pathways. Normally, a ligand would bind to a G-protein which then releases an alpha subunit that creates cAMP, which is a secondary messenger that amplifies the message and targets different parts within the cell. But when the poison that is found in anthrax is present, it targets the enzyme adenylate cyclase thus changing it’s shape, making it not able to convert ATP to cAMP. As a result, the signal transduction pathway is disrupted and the cellular response is altered. Another example is diabetes. Diabetes is a disease in which the body has shortage of insulin, a decreased ability to use insulin, or both. Insulin is a hormone that allows glucose to enter cells and be converted to energy. In each of our bodies there is an insulin receptor that sits on the surface of specific target cells. Once insulin binds to that receptor, a series of events occurs within the cell including an effect on the glucose transporter (GLUT) which allows the cell to take in glucose to make use of it by storing it as glycogen. With Type 1 Diabetes, a person is not producing insulin, therefore it doesn’t have the capabilities of binding with the receptor. With Type 2 Diabetes, the insulin receptor is ignoring the message that is trying to come through ultimately disrupting the signal transduction pathway by inactivating GLUT and as a result the person doesn’t take in glucose. • MC Question: • If the insulin receptor located on a target cell was to become inhibited, what would most likely be the result of this disruption? • (Look at diagram to the right) • Insulin would still bind to the receptor protein but no message would be relayed. • Insulin would diffuse through the cell membrane and target an intracellular receptor that was active. • The amount of glucose would increase. • The cells would eventually die due to the fact that there was no cellular activity (cell communication) taking place because the receptors were inhibited. • Free response: A group of scientists are designing an experiment in which they are trying to figure out how to inhibit a disruption in the signal transduction pathway via cell communication. • Describe the process that occurs during normal cell communication • Discuss one thing that could help the inhibition of these pathways • Provide evidence of a real life disease that results in a disruption to these pathways

  23. MC Question: • If the insulin receptor located on a target cell was to become inhibited, what would most likely be the result of this disruption? • Insulin would still bind to the receptor protein and a message would be relayed. • Insulin would diffuse through the cell membrane and target an intracellular receptor that was active. • The amount of glucose would increase. • The cells would eventually die due to the fact that there was no cellular activity (cell communication) taking place because the receptors were inhibited. A is not correct because if insulin were to bind to a receptor that is inhibited then the message would not be relayed. B is not correct because insulin can’t diffuse through a cell because it is a protein (hormone) and it would be too big to pass through. D is not correct because cells don’t die because there isn’t any cellular activity, they die from programmed cell death or exposure to harmful environments. C is the answer because since the receptors are inhibited, insulin can’t bind which then can’t open the glucose transporter (GLUT) so the amount of glucose levels would increase since glucose can’t be taken into the cell for storage as glycogen. • Free response: A group of scientists are designing an experiment in which they are trying to figure out how to inhibit a disruption in the signal transduction pathway via cell communication. • Describe the process that occurs during normal cell communication • Discuss one thing that could help the inhibition of these pathways • Provide evidence of a real life disease that results in disruption to these pathways Cell communication can occur through short or long distances. Cell communication starts out with reception when a ligand binds to a receptor, then transduction when the message is being amplified through a series of steps with the use of secondary messengers, and it finally results in a cellular response. One way that the scientists could inhibit this disruption is to inhibit the receptor in which the ligand binds to. If that is inhibited then no message can be relayed causing no disruption in the signal transduction pathway, also creating no cellular response. A real life disease in which this occurs is diabetes. With Type 1 Diabetes, a person is not producing insulin, therefore it doesn’t have the capabilities of binding with the receptor. With Type 2 Diabetes, the insulin receptor is ignoring the message that is trying to come through ultimately disrupting the signal transduction pathway by inactivating GLUT and as a result the person doesn’t take in glucose.

  24. LO 1.11: The student is able to design a plan to answer scientific questions regarding how organisms have changed over time using information from morphology, biochemistry, and geology. (See SP 4.2) • SP 4.2: The student can design a plan for collecting data to answer a particular scientific question. • Explanation: All organisms can be linked to other organisms in some way by common ancestry , and over a long period of time have branched off into their own species. Determining how organisms have evolved can be done by looking at physical features of the current organism and comparing them to those in fossils of the ancestor or to other organisms with similar structures. Depending on which rock layer a fossil is found in gives a rough estimate of when that organism lived, which helps scientists more easily place that species on a phylogenetic tree for comparisons and sequencing of ancestry. Genetic analysis shows similarities between organisms in terms of how many base pairs or amino acids are different. As time goes on, DNA/RNA sequences will change, leading to evolution of a species or the creation of a whole new species. To determine how organisms have changed over time, compare fossils or genetic sequences to see changes in physical structures or compare DNA sequences to see how mutations have led to evolution.

  25. MC Question: Three fossils of now-extinct organisms are found: one in rock layer B, one in C, and one in D. Which one will have physical structures that most resemble those of an organism that thrives today? A) The one in rock layer B B) The one in rock layer C C)The one in rock layer D D) Cannot be determined LL/FRQ Style Question: Assume that a particular species of frog and a particular species of lizard have a common ancestor, which is now extinct. Where the frogs and lizards live now was covered by water many hundreds of thousands of years ago, but now is mostly dried up. A) Describe the best way to learn the physical structures of the common ancestor. B) Assume the common ancestor is a fish with two pectoral and two abdominal fins. When the water dried up, what structural changes would you expect to see happening over a gradual period of time? Biochemistry involves the study of DNA sequences and genes. Morphology involves the study of the form and structure of organisms and their specific structural features. C) Using evidence from either biochemistry or morphology, describe one way that you would find evidence to show how species change over time and become different than their ancestor. Describe how that evidence proves that a species has changed from its common ancestor. A B C D

  26. MC Question: Three fossils of now-extinct organisms are found: one in rock layer B, one in C, and one in D. Which one will have physical structures that most resemble those of an organism that thrives today? A) The one in rock layer B B) The one in rock layer C C)The one in rock layer D D) Cannot be determined • A is correct because the fossil in layer B will be the youngest of the three, because the further down in the ground a fossil is, the older it is. Because the fossil in layer B is the youngest, it will be most closely related to an animal that lives today, meaning that their structures will be the most similar. LL/FRQ Style Question: • A) The best way to learn the physical structures of the common ancestor are to look at fossils of it. Fossils provide a depiction of what exactly the organism looked like, and therefore, we will learn the structures the organism had based on what structures we see in the fossil. • B) We would expect to see the fins gradually take the shape of legs. We know that lizards and frogs have legs, and they need them to travel on land. As the water dried up, there was no need to have fins anymore, and organisms with structures allowing them to be more mobile on land would be favored. Also, the four fins are already in an ideal place to become legs.

  27. C) Biochemistry: To find evidence of how the species has changed over time, sequence the DNA of the ancestor and the present day species that is a descendant of the ancestor. By finding differences in the sequences of their DNA, it can be determined what genes are different than the ancestor. By having differences in the sequencing of DNA, we can see how exactly on a molecular level the species has changed over time. OR Morphology: To find evidence of how the species has changed over time, examine the structures of the current day animal and the ancestor by using fossils, and make observations of the similarities and differences. By finding different physical features, we know that the species has changed over time from its ancestor. Similarities in form will show ancestry, but there still should be some differences in structure as some structures are favored over others as conditions change. This picture shows similar structure in four different organisms. We know by the similar structure that there is common ancestry involved, however, the structures are slightly different. The common ancestor must have encountered some environmental pressure that made it need different functions for its limbs, leading to a physical change in structure.

  28. LO 4.9 The student is able to predict the effects of a change in a component(s) of a biological system on the functionality of an organism(s).SP 6.4 The student can make claims and predictions about natural phenomena based on scientific theories and models. Explanation: A Biological system is one uses free energy to maintain equilibrium, reproduce, and grow. They further use different means to obtain and utilize free energy and other resources. The goal outlined by Learning Objective 4.9 is to allow for the student to better understand the effects that are associated with changes to components of living systems, and how any changes would effect the ways in which the organism functions and adapts accordingly. Using SP 6.4, a student should be able to draw parallels between different scientific evidence to assess potential results that would occur with these changes. MC Question: What effects upon an organism would occur if it has contracted diabetes and the pancreas is no longer able to produce any or sufficient insulin? • The blood sugar levels of the organism would decrease. • The blood cells would become turgid due to the lack of homeostasis. • The blood sugar levels of the organism would increase. • There would be increased blockage in the organism’s arteries. Learning Log/FRQ: Describe how the Human Immunodeficiency Virus attacks the components of an organism and affects the functionality of the immune system? Identify what type of virus the HIV virus is and describe how it reproduces itself in the host biological system. Assess why a multitude of AIDS patients ultimately die of common illnesses.

  29. LO 4.9/ SP 6.4 (Answers) • Multiple Choice Answer: • (C) is the correct answer because the lack of insulin would make it hard for the body to break down sugars, leaving higher glucose concentration in the blood, which would make (A) incorrect. (B) is incorrect because the insulin or lack of insulin has no effect on the concentration of the blood cells, which affect turgidity, and (D) is incorrect because the diabetes has no correlation to increase of plaque in arteries • Learning Log/FRQ Answer The HIV virus attacks important immune system cells known as helper-T cells that lyses infected cells, so without these helper-T cells, the immune system would not work properly and leave the individual to be vulnerable to diseases. . The HIV Virus is a type of retrovirus that reproduces by binding to a blood cell and injecting the nucleic acid and reverse transcriptase into the cell that will translate the RNA into DNA and transport it to the nucleus of the cell where it will be integrated with the DNA of the host cell. Thus the cell creates more HIV cells and once it reaches full capacity the blood cell lyses and releases the reproduced HIV cells that can repeat the process on other blood cells. Once this stage has occurred, the organism has contracted AIDS, and their immune system is heavily compromised. Thus, they are left vulnerable to diseases, and could potentially die of common illnesses due to the helper T-cells being unable to properly carry out their jobs.

  30. LO 2.24: The student is able to analyze data to identify possible patterns and relationships between a biotic or abiotic factor and a biological system (cells, organisms, populations, communities or ecosystems). SP 5.1: The student can analyze data to identify patterns or relationships. Explanation: In regards to cell activity, for example, a plant would lose some of its water through evapotranspiration if it’s exposed to too much sunlight. (If the data were recorded it would show how as light exposure increased so would the rate of evapotranspiration.) In contrast, if a short night plant isn’t exposed to sufficient sunlight it won’t flower since the night wasn’t shorter than a critical duration.(Data would show low flowering rates in relation to low amounts of light exposure.) Also, a plant cell will produce abscisic acid when it’s cold (low temperatures) which will inhibit the growth of this organism. (Low temperatures would then correlate with decreased growth of individuals.) An organism’s activities are also affected by its interactions with biotic and abiotic factors. Such an example would be that when temperatures get severely low (long, cold winters) some animals hibernate; woodchucks’ heartbeats go from 80 to 4 or 5 beats per minute, also dropping body temperatures 60 degrees (oF) below normal. (If data were to be recorded it would show the relationship between cold weather and the hibernation patterns of animals.) The stability of populations, communities, and ecosystems is also affected by interactions with factors such as water availability, food chains, and population density. Such as how most plant populations won't thrive during droughts (Decreased water becoming correlated with the decrease of those plant populations.), or how more competition may lower the survival rate of a certain species (Increased population of one species decreasing that of another.). M.C. Question: Based on the data provided which can be inferred? I. The abiotic factor has no association/correlation with the size of the population. II. Crop production increases as annual precipitation increases.III. The biological system presented in this question affects the abiotic factor shown. A) Only IIIB) II and IIIC) I, II, and IIID) Only IIE) I and II Slide 1 of 4

  31. a. Identify two abiotic factors that could cause the fluctuations seen in the graph provided. i. Elaborate on one of the abiotic factors you identified. b. Identify two biotic factors that could cause the fluctuations seen in the graph provided. i. Elaborate on one of the biotic factors you identified. Learning Log/FRQ-style Question: Biological systems such as populations are affected by both biotic and abiotic factors. Slide 2 of 4

  32. ANSWER KEY-LO 2.24 Based on the data provided which can be inferred? I. The abiotic factor has no association/correlation with the size of the population. II. Crop production increases as annual precipitation increases.III. The biological system presented in this question affects the abiotic factor shown. A) Only IIIB) II and IIIC) I, II, and IIID) Only IIE) I and II -------------------------------------------------------------------------------------------------------------------------------------------------------------------- A) III is wrong since the biological system (population-size) is the response variable not the explanatory one.B) Can’t be right since it includes III (see A).C)Can’t be right since it includes III and I (see A for III, and E for I).D) II is right since as X (annual precipitation) increases then Y (crop production) increases.E) Can’t be right since it includes I; I is wrong since there is an association evident between the explanatory variable (annual precipitation-abiotic factor) and the response variable (population size) (positive slope seen). Slide 3 of 4

  33. Biological systems such as populations are affected by both biotic and abiotic factors. a. Identify two abiotic factors that could cause the fluctuations seen in the graph provided. i. Elaborate on one of the abiotic factors you identified. b. Identify two biotic factors that could cause the fluctuations seen in the graph provided. i. Elaborate on one of the biotic factors you identified. a. One abiotic factor that could cause these fluctuations is rain, which affects water availability. Such as how some years there are droughts and during others there’s plenty of water available and isn’t a concern to the populations found within a given area. Another abiotic factor could be wind. Such as how wind helps/aids in the dispersion of dandelion seeds. If winds aren’t strong enough during a pollination season it would decrease the population of the next generation. i. During a period of drought the population size of a grass would decrease due to lack of water. After the period of drought the population would once again flourish and be abundant in its location of growth. Due to all the land that was available too much grass flourished depleting the amount of nutrients in the soil causing the population to once again decrease. Then once there’s a good amount of rain in a certain period that would help restore some of the nutrients in the land. Changes would continue to happen in this manner going from plenty of individuals to the population number dropping again. b. One biotic factor that could cause the fluctuations seen would be the amount of plants available. Such as not enough grass being able to maintain the current population of rabbits. Another biotic factor would be an animal. Such as there being more of a predatory population than the prey population, affecting one another. i. During a year when the population of rabbits(the prey) increases the population of wolves would then increase as well (the predator). The wolf population would then exceed its carrying capacity by overhunting the rabbit population of rabbits, decreasing one of their resources. Then the wolf population would decrease due to starvation/competition for resources, allowing for the population of rabbits to once again be restored. This increase and decrease (the fluctuations observed on the graph) in wolf population would continue in this manner. Slide 4 of 4

  34. Learning Object 2.36: The student is able to justify scientific claims with evidence to show how timing and coordination of physiological events involve regulation. Science Practice 6.1: The student can justify claims with evidence. Explanation: The timing and coordination of physiological events like hibernation, estivation, circadian rhythms, and such are in response to internal and external cues both environmental and systemic. Physiological events occur in tandem with environmental changes, like hibernation during the winter or a nocturnal species sleeping during the daylight. In hibernation, species go into torpor, or a low activity state with decreased metabolism, which allows them to conserve energy in times where temperatures are extreme or food is not easily available. Squirrels, for example, provide evidence of this situation: in the winter the Belding’s ground squirrel drops body temperature from 37 C to close to freezing and regulates its metabolism down to about 5-8 kcal per day from around 85 kcal per day. Plants respond mainly to the stimuli of phototropism and photoperiodism or the response to light or length of light, which generally corresponds to certain times during each day. • Free Response Question: A study was done on a representative group of ground squirrels whose body temperature and metabolic rates were measured for one month. The results are summarized in the graph to the right. The dashed line represents the mean metabolic rate for the ground squirrels during the summer time when they do not hibernate. Considering the diagram to the right, answer the following questions: • Describe the graph and explain what the changes in body temperature and metabolic rate indicate in terms of hibernation. • Explain the evolutionary advantage of hibernation for ground squirrels. Justify your conclusions using evidence from the graph. • Identify and describe the method of regulation of metabolic rate during hibernation and what triggers it. • Multiple Choice: Which of the following scenarios is not an example of regulation of physiological events by timing or coordination? • Plants like clover and carnations are long-day plants while hemp and cotton are short-day plants based on the length of the night • Bees dance in specific patterns to alert fellow bees where food can be found • A biological clock triggers stomata to open and close in an approximately 24 hour cycle • Bacteria use quorum sensing based on density to organize antibiotic resistance, virulence, and biofilm formation http://ajpregu.physiology.org/content/ajpregu/302/1/R15/F1.large.jpg?width=800&height=600

  35. Free Response Question: A study was done on a representative group of ground squirrels whose body temperature and metabolic rates were measured for one month. The results are summarized in the graph to the right. The dashed line represents the mean metabolic rate for the ground squirrels during the summer time when they do not hibernate. Considering the diagram to the right, answer the following questions: • Describe the graph and explain what the changes in body temperature and metabolic rate indicate in terms of hibernation. • Explain the evolutionary advantage of hibernation for ground squirrels. Justify your conclusions using evidence from the graph. • Identify and describe a possible method of regulation of metabolic rate during hibernation and what triggers it. • Sample Answer: • a. The graph has three peaks that reach about 40 degrees C and a metabolic rate of 5 mL O2h-1 g-1 that last for very short periods of time around a few hours. Between these spikes are much lower fluctuating periods with a small variability. These areas stay rather steady at 4 degrees C and oscillate in metabolic rate between above 0 and 1 mL O2h-1g-1 . The lower extended periods last about ten minutes and represent the torpor stage of the hibernation. In this period, the core body temperature lowers such that all protein activity slows and the overall metabolic rate slows. The spikes indicate the animal waking up to complete maintenance type functions that require a higher metabolic rate before returning to the torpor. • Multiple Choice: Which of the following scenarios is not an example of regulation of physiological events by timing or coordination? • Plants like clover and carnations are long-day plants while hemp and cotton are short-day plants based on the length of the night • Bees dance in specific patterns to alert fellow bees where food can be found • A biological clock triggers stomata to open and close in an approximately 24 hour cycle • Bacteria use quorum sensing based on density to organize antibiotic resistance, virulence, and biofilm formation • B is the correct answer. Choice A involves the regulation of plant flowering based on the critical darkness periods that the plant receives. Choice C is an example of a circadian rhythm triggering stomata to open and close based on the daytime in response to transpiration. Choice D is bacteria responding to density based cues to coordinate a response to various stimuli. The figure below demonstrates this effect. The triangles represent quorum sensing molecules that are a form of communication between bacteria. Choice B, however, is a reference to the studies of Karl von Frisch who observed the manners in which honey bees communicate to other bees. b. Hibernation is an adaptive evolutionary trait that allows ground squirrels a better chance to survive and pass on the trait. During hibernation, the squirrels can conserve a large amount of energy by existing in a low metabolic rate state. The metabolic rate is the sum of all chemical reactions occurring within the organism, many of which require ATP. In the winter there food is less available due to the cold and therefore minimized opportunities to obtain glucose to power cellular respiration to produce ATP. Further, more energy would be required for squirrels to maintain their usual high core temperature during the cold because of their endothermic nature. The total area under the graph of the metabolic rate for the hibernation is much less than the area underneath the mean summer metabolic rate, which lies at about 1.3 O2 h-1 g-1, much higher than the around 0.2 O2 h-1 g-1 norm for hibernation. For the aforementioned reason of cold temperature requiring more energy to maintain body heat, the mean metabolic rate for winter without hibernation may even be higher than that for summer when there is already heat. This overall conservation of energy allows the ground squirrel a much better chance of surviving the winter and reproducing. c. Hibernation is triggered by a prolonged change in temperature. Periods of cold weather slow down the body’s metabolic processes by lowering kinetic energy and thus overall energy and reactions. Thus, in hibernation, animals like ground squirrels allow their body temperatures to drop very low such that the metabolic rate is greatly slowed as kinetic energy takes a sharp decline. As seen in the graph, temperature and metabolic rate are closely linked such that this explanation can be backed that the lowering of temperature leads to the slowing of the metabolic rate. http://1.bp.blogspot.com/-9AB7B7u_JqM/TdMrztsRrCI/AAAAAAAAJMw/k0wKULTSMKg/s1600/bob1.jpg

  36. LO 2.20 The student is able to justify that positive feedback mechanisms amplify responses in organisms. • SP 6.1 The student can justify claims with evidence. • Regarding the numerous processes in biological organisms, responses are amplified by positive feedback mechanisms. Positive feedback involves a change in some variable that triggers mechanisms that amplify rather than reverse the change. For example, during childbirth, the pressure of the baby’s head against receptors near the opening of the uterus stimulates uterine contractions, which cause greater pressure against the uterine opening, heightening the contractions, which still causes greater pressure. As a result, the response initiated by the variable moves farther away from the initial set-point. Another example deals with the ripening of fruit. A ripening apple, for instance, releases the plant hormone ethylene , which accelerates the ripening of unripe fruit in its vicinity. This causes the surrounding fruits to produce more ethylene, amplifying the process. • MC: Which of these conditions indicate positive feedback has occurred? • A) Vigorous exercise raises body temperatures above normal, and sweat is produced. • B) Once a vessel is damaged, platelets start to cling to the injured site and release chemicals that attract more platelets. • C) When the body temperature drops, blood vessels constrict, and shivering begins. • D) A decrease in oxygen causes the kidneys to secrete erythropoietin, a hormone that stimulates the production of red blood cells. • FR: Distinguish the difference between positive feedback and negative feedback, and provide examples for each. Why are feedback loops important?

  37. MC: Which of these conditions indicate positive feedback has occurred? A) Vigorous exercise raises body temperatures above normal, and sweat is produced. B) Once a vessel is damaged, platelets start to cling to the injured site and release chemicals that attract more platelets. C) When the body temperature drops, blood vessels constrict, and shivering begins. D) A decrease in oxygen causes the kidneys to secrete erythropoietin, a hormone that stimulates the production of red blood cells. B is the correct answer because it is the only answer choice that demonstrates positive feedback. With blood clotting, the platelets continue to pile up and release chemicals until a clot is formed, thus initiating an amplified response. Answer choices A, C, and D are all examples of negative feedback. We know this because in each case, a change in the variable being monitored triggers the control mechanism to counteract further change in the same direction. When the body temperatures are above normal or below normal, sweat or shivering is the response that is used to reverse the output. Same thing with D, if there is a lack of oxygen, a hormone that stimulates the production of red blood cells is secreted. FR: Distinguish the difference between positive feedback and negative feedback, and provide examples for each. Why are feedback loops important? With negative feedback, the output reduces the original effect of the stimulus. In a positive feedback system, the output enhances the original stimulus. An example of negative feedback is the control of blood sugar with insulin. When blood sugar rises, receptors in the body sense a change . In turn, the pancreas secretes insulin into the blood effectively lowering blood sugar levels. Once blood sugar levels reach homeostasis, the pancreas stops releasing insulin. An example of positive feedback is lactation. As the baby suckles on the nipple there is a nerve response into the spinal cord and up into the hypothalamus of the brain, which then stimulates the pituitary gland to produce more prolactin to produce more milk. Feedback loops are important in ensuring the receptor will not continue to stimulate the effector, leading to an overcorrection and causing a deviation in the opposite direction. Image courtesy of http://biology-forums.com/index.php?action=gallery;sa=view;id=1077

  38. LO 1.10 The student is able to refine evidence based on data from many scientific disciplines that support biological evolution. SP 5.2: The student can refine observations and measurements based on data analysis. Explanation: Natural selection is a major component in supporting biological evolution. Natural selection was exposed broadly by Charles Darwin. Natural selection is the theory that states the more favorable a phenotype is more likely it is to survive and pass the gene through offspring. Also another piece of evidence would be homologous structures. Homologous structures are structures that have various development and structures with different functions. Analogous structures are the complete opposite these organisms have the same function with no trace of a common ancestor. These biological theories can be measured and refined through a series of process such as analysis of cladograms, analysis of phylogenetic trees and measurements of fitness(reproductive success). M.C. Based on the cladogram provided which specie has the most recent common ancestor to the Rodents and Rabbits ? ( next page) A. Birds B. Amniotic Egg C. Primates D. Sharks F.R. / L.L: Based on your knowledge of biological evolution explain the following: A.) Compare & contrast divergent and convergent evolution and its significance to Biological evolution.

  39. Answer Keys Answer Keys M.C. Based on the cladogram provided which specie has the most recent common ancestor to the Rodents and Rabbits ? A. Birds B. Amniotic Egg C. Primates D. Sharks C: Is the correct answer because the Primates and Rabbits are branched off from each other. This branch is a symbolizing the common ancestor. Compare & Contrast divergent and convergent evolution and its significance to biological evolution: Divergent evolution is one specie that develops into two species over time. For example the Wooly Mammoth(extinct) that developed into the common Elephant today. The newly created specie live in different ways from the common ancestor. They are created through migration or near extinction. Convergent evolution is when two different unrelated organisms develop common features because, of adapting in similar environments. This is is significant in biological evolution because it creates biological variation and ensures that each species plays out its niche.

  40. LO 3.34: The student is able to construct explanations of cell communication through cell-to-cell direct contact or through chemical signaling. SP 6.2:The student can construct explanations of phenomena based on evidence produced through scientific practices. Explanation: The process of cell communication is primarily executed via direct contact between two cells, mainly through means of surface receptors located on the outer membranes of cells, which, upon activation by a stimulus, subsequently trigger the signal transduction pathway within the recipient cell to trigger a response. Direct communication may also transgress via gap junctions or plasmodesmata that allow materials to be transported between animal and plant cells, respectively. Another form of cellular communication involves that of chemical signaling, which functions similarly to direct contact, save for the use of secreted chemical signals rather than membrane-integrated signal molecules to perform communicative tasks, such as with the intracellular activation of responses from chemical signals, localized synaptic signaling between neurons, and more long-distance hormonal signaling between an endocrine cell and its respective target cell. MC Question: Cell surface receptors consist of each of the following, excluding: a) G protein linked b) Enzymatic receptors c) Single-pass transmembrane proteins d) Chemically-gated ion channels FRQ Question:The endocrine system utilizes cell-to-cell communication to initiate responses upon any internal or external environmental change. Describe each of the three pathways that make up hormonal distribution in the body, taking note of specific chemical signals and receptors used in each to carry out cellular communication.

  41. MC Question: Cell surface receptors consist of each of the following, excluding: a) G protein linked b) Enzymatic receptors c) Single-pass transmembrane proteins d) Chemically-gated ion channels FRQ Question:The endocrine system utilizes cell-to-cell communication to initiate responses upon any internal or external environmental change. Describe each of the three pathways that make up hormonal distribution in the body, taking note of specific chemical signals and receptors used in each to carry out cellular communication. The simple endocrine pathway, in response a stimulus, triggers a receptor protein on an endocrine cell, which subsequently releases hormones into a blood vessel to the corresponding target cell, triggering the response. The simple neurohormone pathway, however, upon stimulation, triggers the activation of either the hypothalamus or posterior pituitary via sensory neurons, causing the release of neurohormones by a neurosecretory cell. The neurohormones then travel though a blood vessel to the target cells, triggering a response. Both simple endocrine pathways and simple neurohormone pathways appear present in the simple neuroendocrine pathway, which involves the stimulation or sensory neurons that activate receptors in the hypothalamus, signaling the release of neurohormones into a blood vessel, which then transport them to receptor sites on an endocrine cell. The cell subsequently releases hormones into another blood vessel that are then transported to the target cell, triggering the response.

  42. LO 3.21 The student can use representations to describe how gene regulation influences cell products and function.SP 1.4 The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively. • M.C. Question:The diagram above is one of an operon. Identify what type of operon it is AND what is needed in order for transcription to happen. • An inducible operon which a corepressor molecule will make the repressor protein inactive and allow transcription to occur. • An inducible operon which an inducer molecule will make the repressor protein inactive and allow transcription to occur. • A repressible operon which a corepressor molecule will make the repressor protein active and allow transcription to occur. • An inducible operon which a inducer molecule will make the repressor protein active and allow transcription to occur. Explanation The products and function of genes are the results from gene expression. While some genes are continually expressed, the expression of most genes are regulated. Regulation allows more efficient energy utilization, allowing an increase in metabolic fitness. Regulatory genes are able to control gene expression through environmental signals and developmental cascades. One of the best studied regulatory systems is the inducible and repressible regulatory systems that use operons in bacteria. Operons are made up of a promoter, an operator, and the genes they control. The operator acts as an “on, off” switch, which is controlled by a protein repressor. The repressor protein, when active, binds to the operator and switches the operon off by blocking RNA polymerase from transcribing the DNA into RNA. A repressible operon is an operon that has the transcription on but can only be inhibited when a corepressor molecule allosterically binds to the repressor protein and makes it active. An inducible operon is an operon that has the transcription off but can only be stimulated when an inducer interacts with repressor protein and makes it inactive. Learning Log/ FRQ-style Question: The diagram above is one of a trp operon that produces polypeptides that make up enzymes for tryptophan synthesis. The operon is inhibited when Trytophan binds to the repressor protein and the active repressor protein binds to the operator. An enzyme called Tryptophandestructase can also bind with tryptophan and denatures it. Suppose Tryptophandestructase was introduced, explain what will happen to the operon. Justify your answer.

  43. LO 3.21 The student can use representations to describe how gene regulation influences cell products and function.SP 1.4 The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively. • M.C. Question:The diagram above is one of an operon. Identify what type of operon it is AND what is needed in order for transcription to happen. • An inducible operon which a corepressor molecule will make the repressor protein inactive and allow transcription to occur. • An inducible operon which an inducer molecule will make the repressor protein inactive and allow transcription to occur. • A repressible operon which a corepressor molecule will make the repressor protein active and allow transcription to occur. • An inducible operon which a inducer molecule will make the repressor protein active and allow transcription to occur. Sample Answer: Because Tryptophan makes the repressor protein active, tryptophan is a corepressor, this would make the trpoperon a repressible operon. Because the operon is repressible, it will continue to function unless the corepressor, tryptophan, binds with the repressor and inhibits the operon. Since tryptophan is being denatured by Tryptophandestructase, the repressor protein will remain inactive, the trpoperon will be uninhibited, and the operon will continue to produce polypeptides that make up enzymes for tryptophan synthesis. Learning Log/ FRQ-style Question: The diagram above is one of a trp operon that produces polypeptides that make up enzymes for tryptophan synthesis. The operon is inhibited when Tryptophan binds to the repressor protein and the active repressor protein binds to the operator. An enzyme called Tryptophandestructase can also bind with tryptophan and denatures it. Suppose Tryptophandestructase was introduced, explain what will happen to the operon. Justify your answer. Slide by Alex Varsik Inducible operon diagram from http://www.biologyjunction.com Trp operon from Campbell Reece Ap Biology Textbook 7th Edtion.

  44. LO 4.19:The student is able to use data analysis to refine observations and measurements regarding the effect of population interactions on patterns of species distribution and abundance.SP 5.2: The student can refine observations and measurements based on data analysis. Explanation: Interactions between populations affect population distribution and abundance because of processes such as competition, predation, and mutualism. The population interactions can have positive effects, where the population change is beneficial, or negative effects, where the change is hurtful. Populations may move out of an area to find more beneficial conditions, which changes both the old and new ecosystems with the loss or gain of a population. This can mean that one ecosystem gains a new species, but loses another because of over predation. Feedback controls play a role in how population changes affect symbiotic relationships within an ecosystem because if one animal preys on another, the preys population size decreases, the predators will not have a large enough food source for their entire population, and their population size will decrease. This shows that there is a very delicate balance between populations. If one population in an area changed in density or dispersion, this would dramatically change many other populations in the area because populations depend on each other. 1/5

  45. M.C Question:The graph shown here depicts the numbers of moose and wolf populations in an area. Infer from the graph what caused the spike in moose population in the years leading up to 1995. a) The increase in number of wolves meant that they had to find other prey, allowing more moose to survive. b) The wolf population was smaller than normal, causing there to be less predators for the moose and more could survive. c) There were extremely good environmental conditions during the moose mating season. d) The moose developed an adaptation that allowed them to escape the wolves. source: http://p4stsbio2010.blogspot.com/2010_09_01_archive.html 2/5

  46. Learning Log/FRQ-style Question: In the graph below, it shows the population changes of a hare and a lynx. Assuming that the lynx is a predator to the hare, answer the following questions about the populations. a) Explain in detail the population changes and why there are peaks and dips in the population size. b) Are the hare and lynx showing positive or negative feedback? How do you know? c) Supposing that the hare is the main food source for the lynx, what would happen to each population if the hare developed an adaptation that protected it from the lynx. What effects would this have on the ecosystem? Source of graph: http://myweb.rollins.edu/jsiry/LeolopoldMountainMeans.html 3/5

  47. Answers Key - LO 4.19 • M.C Question:The graph shown here depicts the numbers of moose and wolf populations in an area. Infer from the graph what caused the spike in moose population in the years leading up to 1995. • a) The increase in number of wolves meant that they had to find other prey, allowing more moose to survive. b) The wolf population was smaller than normal, causing there to be less predators for the moose and more could survive. c) There were extremely good environmental conditions during the moose mating season. d) The moose developed an adaptation that allowed them to escape the wolves. We know the answer is B because in the graph, you can see there is a sharp increase in the moose population at the same time the wolf population is at its lowest points. This means that more moose can survive because there is less threat of predators. 4/5

  48. Answers Key - LO 4.19 • In the graph below, it shows the population changes of a hare and a lynx. Assuming that the lynx is a predator to the hare, answer the following questions about the populations. a) Explain in detail the population changes and why there are peaks and dips in the population size. b) Are the hare and lynx showing positive or negative feedback? How do you know? c) Supposing that the hare is the main food source for the lynx, what would happen to each population if the hare developed an adaptation that protected it from the lynx. What effects would this have on the ecosystem? a) The populations of the hare and the lynx are connected, and change together. When the hare’s population increases, so does the population in the lynx because they have more of their food source, causing a peak in the populations. The predation of the hare from the increased lynx population results in the decrease of the number of hare, also causing a dip in the lynx populations. b) The hare and the lynx are showing positive feedback because they move in the same direction. When one population goes up, so does the other and vice-versa. c) If the hare adapted something to protect it from the lynx, than the hare population would increase without predation while the lynx population decreased because of their loss of food supply. In the ecosystem, this could have disastrous effects because the hares would need more food to feed their growing population, and without a proper check on the hare population, their population would consume all the food in the area, disrupting the entire food chain. 5/5

  49. Learning Objective 2.1 LO 2.1: The student is able to explain how biological systems use free energy based on empirical data that all organisms require constant energy input to maintain organization, to grow and to reproduce. SP 6.2: The student can construct explanations of phenomena based on evidence produced through scientific practices. We can tell organisms use energy and need energy for metabolic processes because of the exchange between the different trophic levels. The law of thermodynamics, which states that matter cannot be created or destroyed, helps explain how energy is used for organisms. Organisms obtain energy from other organisms and use that energy in energy coupling reactions. This means that there must be a constant energy input in order increase or decrease the entropy. There is a transfer of energy by photosynthesis or chemosynthesis from free energy reactions. There is evidence of this energy transfer in metabolic rates, physiological changes, variations in reproductive strategies, and effects of changes in free energy availability. If there is an offset of free energy availability for a clover population, a change in population size can be seen in that autotrophic population as well as a rabbit population (heterotrophic) that uses the clovers for energy. M.C. Question: If someone standing still on the edge of a diving board was pushed off the board into a pool below the board, which of the following is true? • The diver will move toward a more stable state the closer to the water they get • The free energy of the diver would increase the closer to the water they get • The movement of the diver from the board to the water is a spontaneous reaction that releases free energy a) I only b) II only c) II and III only d) I and III only FRQ: Using the figure, describe where each organism is obtaining energy, two chemical processes responsible for the harnessing of energy, and what happens to the energy as it is transferred from each trophic level.