Cell Unit Review

1. Cell Unit Review

2. Question 1. State one reason that most foods must be digested before they can enter a cell?

3. B B C C Question 2. The diagrams below represent two cells, x and Y. (a) Select one lettered organelle and write the letter of that organelle. Identify the organelle you selected.

4. B B C C Question 2. The diagrams below represent two cells, x and Y. (b) State one function of the organelle that you identified in part (a)

5. B B C C Question 3. Identify one process that is carried out in cell Y in the diagram that is not carried out in cell X.

6. Question 4. It was once thought that decaying meat turned into maggots (fly larvae). Careful experimentation by scientists demonstrated that maggots actually come from fly eggs and not meat. These experiments illustrate that new individuals result only from • Nutrition and replication • Metabolic homeostasis • Reproduction and development • Genetic engineering

7. Question 5. In a cell, all organelles work together to carry out • Information storage • Diffusion • Metabolic processes • Active transport

8. Question 6. Some human body cells are shown in the diagram below. These groups of cells represent different • Tissues in which similar cells function together • Organelles that carry out different functions • Organs that help to carry out a specific life activity • Systems that are responsible for a specific life activity

9. Question 7. Organelles carry out specific processes involving chemical reactions. In the chart below identify two organelles and, for each, identify a process involving chemical reactions that occurs there. Describe one specific way each process identified is important to the functioning of the organism.

10. Question 8. Muscle cells in athletes often have more mitochondria than muscle cells in nonathletes. Based on this observation, it can be inferred that the muscle cells in athletes • Have a smaller demand for cell proteins than the muscle cells of nonathletes • Have a greater demand for energy than the muscle cells of nonathletes • Have nuclei containing more DNA than nuclei in the muscle cells of nonathletes • Reproduce less frequently than the muscle cells of nonathletes

11. Question 9. After a hormone enters the bloodstream, it is transported throughout the body, but the hormone affects only certain cells. The reason only certain cells are affected is that the membranes of these cells have specific • Receptors • Carbohydrates • Tissues • Antibodies

12. Question 10. The diagram below represents two single-celled organisms. These organisms carry out the activities needed to maintain homeostasis by using specialized internal A) Tissues B) organs C) organelles D) systems

13. Question 11. Plants in areas with short growing seasons often have more chloroplasts in their cells than plants in areas with longer growing seasons. Compared to plants in areas with longer growing seasons, plants in areas with shorter growing seasons most likely • Make and store food more quickly • Have a different method of respiration • Grow taller • Have a higher rate of protein metabolism

14. Question 12. In a cell, information that controls the production of proteins must pass from the nucleus to the • Mitochondria • Chloroplasts • Ribosomes • Cell membrane

15. Question 13. Cellular communication is illustrated in the diagram below Information can be sent from • Cell A to Cell B because cell B is able to recognize signal 1 • Cell B to Cell A because cell B is able to recognize signal 2 • Cell B to Cell A because cell A is able to recognize signal 1 • Cell A to Cell B because cell A is able to recognize signal 2

16. Question 14. Which substance are found on cell surfaces and respond to nerve and hormone signals? • Vitamins and minerals • Subunits of DNA • Receptor molecules • Starches and simple sugars

17. Question 15. Hormones and secretions of the nervous system are chemical messengers that • Store genetic information • Extract energy from nutrients • Coordinate system interactions • Carry out the circulation of materials

18. Question 16. Every single-celled organism is able to survive because it carries out • Autotrophic nutrition • Sexual reproduction • Metabolic activities • Heterotrophic nutrition

19. Question 17. In multicelluar organisms, cells must be able to communicate with each other. Structures that enable most cells to communicate with each other are known as • Chloroplasts • Pathogenic agents • Receptor molecules • Antibiotics

20. Question 18. Studies of fat cells and thyroid cells show that fat cells have fewer mitochondria than thyroid cells. A biologist would most likely infer that fat tissue • Requires more energy than thyroid tissue • Has energy requirements equal to those of thyroid tissue • Does not require energy • Requires less energy than thyroid tissue

21. Question 19. Which statement regarding the functioning of the cell membrane of all organisms is not correct? • The cell membrane forms a boundary that separates the cellular contents from the outside environment. • The cell membrane forms a barrier that keeps all substances that might harm the cell from entering the cell. • The cell membrane controls the movement of molecules into and out of the cell. • The cell membrane is capable of receiving and recognizing chemical signals.

22. Question 20. While viewing a slide of rapidly moving sperm cells, a student concludes that these cells require large amounts of energy to maintain their activity. The organelles that most directly provide this energy are known as • Ribosomes • Chloroplasts • Mitochondria • Vacuoles

23. Question 21. In the given diagram of a single-celled organism, that arrows indicate various activities taking place. Which systems perform these same activities in humans? • Respiratory, nervous and endocrine • Excretory, respiratory, and reproductive • Digestive, circulatory, and immune • Respiratory, excretory, and digestive