Understanding Key Ecological Concepts: Energy Flow, Population Dynamics, and Sustainability
This concise guide covers fundamental ecological principles such as energy flow through ecosystems, the importance of biodiversity, and the processes behind carbon and nitrogen cycling. It elaborates on energy transfer between trophic levels, population growth dynamics, and the role of limiting factors affecting population density. The discussion also includes macromolecules, cellular structures, and key processes like photosynthesis and cellular respiration. Emphasizing sustainability, it suggests choices that support future ecological balance.
Understanding Key Ecological Concepts: Energy Flow, Population Dynamics, and Sustainability
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Presentation Transcript
Ecology Big Ideas
Energy • Energy flows through every ecological system • Inputs = what goes into the ecosystem • Outputs = what goes out of the system
Food Webs • Increased biodiversity means a healthier ecosystem
Energy Transfer between Trophic Levels • 10% Energy Transfer • Producers make up largest biomass
Bioaccumulations • Toxins cannot be removed and increase in amount between trophic levels
Carbon Cycle • Cyclescarbon through the ecosystem • Contains photosynthesis and cellular respiration • Opposite chemical reactions
Nitrogen Cycle • Cycles nitrogen through the system • Bacteria takes nitrogen from the atmosphere and transfers it to plants
Population Growth • Populations will grow exponentially if there are no limitingfactors
Population Growth • Populations will reach carryingcapacity because of limiting factors which include: • Abiotic (non-living) • Space & Water • Biotic (living) • Food & Predators
Population Density • Population Densityis the number of living things in an area • Example: • 500 moose in 10 sq. miles = 50 moose per mile
General Ecology • Non-native species usually DIE in a new environment, some survive and take over if they have no predators
Sustainability • Maintaining resources for future use • Choices we can make now that support sustainability • Substituting renewable (?) for non-renewable (?) resources • Recycling • Using fewer resources
Macromolecules • Carbohydrates: made of simple sugar units glucose, galactose, fructose • Lipids: fats, etc. • Triglycerides made of glycerol & 3 fatty acid tails • Phospholipids made of phosphate head & 2 fatty acid tails
Macromolecules • Proteins: made of amino acids • Nucleic Acids – DNA & RNA: made of nucleotides
Cell Structure & Function Big Ideas
Main Cell Types • Prokaryotes – no nucleus, nucleoid region of DNA; bacteria • Eukaryotes – DNA contained in nucleus, membrane bound organelles; everything except bacteria
Key Cell Components/Organelles • Nucleus – DNA • Ribosomes – Site of Protein Synthesis • Endoplasmic Reticulum – assembly of lipids & finishing work on proteins, etc. • Golgi Apparatus – modifies, sorts and packages proteins, etc. from ER for storage or release to outside of cell. • Mitochondria – breakdown of glucose into ATP • Chloroplasts – convert sun energy into sugars • Vacuoles & Vesicles – storage/movement of water, etc. • Lysosomes – bread down of macromolecules and old organelles.
Cell Boundaries & Movement of Materials Across Them • Cell wall – rigid structure outside cell membrane for support, protection; found in bacteria, fungi, plants • Cell membrane – flexible barrier between inside and outside of the cell • Composed of phospholipidbilayer, proteins • Selectively permeable – allows some things in/out, but not others.
Cell Transport • Passive Transport – no cellular energy used • Diffusion – movement of materials from high to low concentration • Facilitated diffusion – diffusion of molecules through protein channels (not directly through membrane) • Osmosis – movement of water from high to low concentration across a membrane (facilitated) • Active Transport - requires cellular energy • Movement of materials across the membrane from low to high concentration
Photosynthesis and Cellular Respiration Big Ideas
Photosynthesis & Cellular Respiration • Photosynthesis and cellular respiration are opposite chemical reactions
Photosynthesis: plants take carbondioxide (CO2) and water (H2O) and make glucose (C6H12O6) and oxygen (O2) • Plants make their own food!!!!!!!!!!!!!!!!
Cellular Respiration: plants AND animals make energy (ATP) by transforming glucose (C6H12O6)and oxygen (O2) into carbondioxide (CO2) and water (H2O) • CHEMICAL Energy in glucose is transformed into the energy to live (ATP) • Very similar to setting something on fire (combustion), which releases carbon dioxide (CO2) into the atmosphere
Be able to trace the path of a carbon atom from air through photosynthesis, cellular respiration and back to the air
Mitosis and Meiosis Big Ideas
Mitosis & Meiosis • Division of Chromosomes in a cell • Chromosomes are made of DNA • DNA is replicated (copied) before each process • Each chromosome contains many sections of DNA called genes which contain the code for a protein
Mitosis • Mitosis: produces twoIDENTICAL cells from one cell for growth and repair of body cells • 2N cells produce 2N cells
Meiosis • Meiosis: produces four UNIQUE sex cells for reproduction • Each cell is 1N – ½ the chromosomes of the body cells • Females: Eggs • Males: Sperm • Allows for differences (variation) in populations • Fertilization restores the 2N number in offspring
DNA and Genetics Big Ideas
DNA & Genetics DNA: deoxyribonucleic acid; is a code for your physical (phenotype) traits - PHYSICAL TRAIT
Traits • Proteins: can be used to make bodystructures, hormones and enzymes • Enzymes act to speedup (catalyze) chemical reactions in the body • Ex. Digestion of food, making DNA, and regulating glucose
GeneticsVocabulary • Phenotype: What your physically look like • Ex. Blue Eyes OR Brown Eyes • Genotype: What your genesare • Ex. Bb, bb, or BB
Vocabulary • Dominant:Trait/gene that is shown • Ex. BB = Brown EyesBb = Brown Eyes • Recessive: Trait/gene that is hidden by a dominant gene • Ex. bb = Blue Eyes Bb = Brown Eyes
Vocabulary • Heterozygous: different genes • Ex. Bb for Brown Eyes • Homozygous: same genes • Ex. bb for Blue Eyes
PunnettSquare: used to predict offspring • Ex. Two heterozygous bunnies are crossed; black fur is the dominant trait • Phenotype ratio • Ex. 25% white bunnies, 75% black bunnies • Genotype ratio • Ex. 25% bb, 50% Bb, 25% BB F f F FF Ff f Ff ff
A detached earlobe man (EE) has children with an attached earlobe woman (ee). What are the possible genotypes (gene combination)? What are the possible phenotypes (physical trait)? Earlobes (E)
A heterozygous tongue roller (Tt) mates with a non-tongue roller (tt), what percentage of their children will be tongue rollers?
What is the percent chance two heterozygous tongue roller will have a non-tongue roller offspring?
Dihybrid crosses – chance of inheriting 2 traits togetherCross 2 heterozygous for color and height (Green & Tall are dom; Yellow & Short are rec.) TG tGTgtg TG tG Tg tg Red = tall Black= short
Protein Synthesis • Transcription • The code in DNA is copied into mRNA • This nucleotide sequence determines the sequence of amino acids in the protein. • mRNA leaves the nucleus and forms a “protein factory” complex with rRNA called a ribosome. • Translation • The nucleotide sequence in mRNA is read 3 nucleotides at a time – a codon. • Each codon corresponds to a specific amino acid. • tRNA brings the needed amino acid to the ribosome. • The amino acids are bonded together to form a protein.
Evolution Big Ideas
Evolution • Evolution: change over time All living things are related to a COMMON ANCESTOR!!!
Evidence of Evolution • Evidence: • Presence of Fossils found in rock layers • Homologous and Vestigial Structures • Homologous: Similar Structures • Vestigial: Unused structures; whale pelvis, human wisdom teeth
Fossil Record Homologous Structures
Evidence of Evolution • DNA Comparisons • Humans and mice are 99% similar in DNA, so they are closely related • Embryos • Closely related organisms have similar embryos
DNA Comparisons Embryos
Natural Selection • Natural Selection: “survival of the fittest, failure of the worst” • Over reproduction sets up a struggle for existence • Natural selection selects for variations in the population (result of mutation & sexual reproduction( that are adaptive • The “goal” of life is to survive and reproduce (pass adaptive genes to next generation)
Mutations in DNA: can (not always) lead to unique traits, which may help or hinder survival!!