Cell Biology Questions and Answers
Cell Biology Questions
1. What are the 3 principal parts of a cell?
– plasma membrane, cytoplasm, nucleus
2. What are the characteristics/properties of the plasma membrane?
– fluidity, selective permeability, asymmetry
3. If you observed that a cell did not have a centrosome, what could you predict about its capacity for cell division?
– the cell probably would not be able to undergo cell division
4. You would expect a cell with an extensive Golgi apparatus to:
– secrete a lot of proteins
5. Regarding the structure of the plasma membrane, which statement is WRONG?
– glycolipids appear only in the membrane layer that faces the extracellular fluid
6. Which organelles are surrounded by a membrane?
– peroxisomes, mitochondria, nucleus
7. How does crossing-over affect the genetic content of the haploid gametes?
– the result of crossing-over is that 4 haploid gametes are genetically unlike each other and genetically unlike the starting cell that produced them
8. What is the significance of interphase?
– to obtain 2 identical duplicated copies of each chromosome prior to entering cell division
9. Which of the following organelles function primarily in decomposition reactions?
– peroxisomes and lysosomes
10. Which of the following statements is NOT part of the cell theory?
– cells are classified in eukaryotes and prokaryotes
11. In which order proteins destined to be secreted move through the secretory pathway?
– Rough ER —> transport vesicles —> Golgi complex —> secretory vesicles —> cell surface
12. Select the CORRECT sequence of steps involved in the gene expression process:
– transcription of a gene from DNA into RNA, export to cytoplasm, translation of RNA into a corresponding sequence of amino acids
13. Which of the following statements regarding the nucleus is TRUE?
– phosphorylation of lamins causes the disassembly of the nuclear lamina and the nucleus
14. The membranous compartmentalization of a cell:
– allows different metabolic processes to occur simultaneously
15. How does anaphase I of meiosis differ from anaphase of mitosis?
– during anaphase I of meiosis, the paired chromatids are held together by a centromere and do not separate. During anaphase of mitosis, sister chromatids separate and the centromeres split.
16. The Na+/K+ pump:
– helps to maintain normal cell tonicity, ensuring that cells neither shrink nor swell due to movement of water
17. What would be the corresponding complementary RNA base sequence from this DNA template base sequence ATG CAT?
– UAC GUA
18. Prolonged administration of the sedative penobarbital results in increased tolerance to the drugs; the same dose no longer produces the same degree of sedation. Which organelle might be involved in the drug tolerance process?
– Smooth ER
19. Examine the following cell.
Based on the internal structure, the cell is likely to be:
– a cardiac cell
20. The enzymes of oxidative metabolism are located in the:
– matrix and inner mitochondrial membrane
21. How does the low pH of lysosomes protect the rest of the cell from lysosomal enzymes in case the lysosome breaks?
– all of the lysosomal enzymes are active at the acidic pH that is maintained within lysosomes but not at the neutral pH characteristic of the rest of the cytoplasm
22. What are the main differences between prokaryotic cell and eukaryotic cell?
– prokaryotic cells lack nucleus and organelles while eukaryotic cells present both nucleus and organelles
23. The hormone insulin regulates metabolism by promoting the absorption of especially glucose from blood to the cells. This action best represents which membrane protein function?
– receptor
24. Regarding the transport of substances across the plasma membrane:
– some substances are transported in vesicles in a passive process out of a cell (exocytosis) or into a cell (endocytosis)
25. The process of a white blood cell engulfing a bacterium is:
– phagocytosis
Answers
1. plasma membrane, cytoplasm, nucleus 2. fluidity, selective permeability, asymmetry 3. the cell probably would not be able to undergo cell division 4. secrete a lot of proteins 5. glycolipids appear only in the membrane layer that faces the extracellular fluid 6. peroxisomes, mitochondria, nucleus (nucleolus & ribosomes DON’T have a membrane) 7. the result of crossing-over is that 4 haploid gametes are genetically unlike each other and genetically unlike the starting cell that produced them 8. to obtain 2 identical duplicated copies of each chromosome prior to entering cell division 9. peroxisomes and lysosomes 10. cells are classified in eukaryotes and prokaryotes 11. Rough ER —> transport vesicles —> Golgi complex —> secretory vesicles —> cell surface 12. transcription of a gene from DNA into RNA, export to cytoplasm, translation of RNA into a corresponding sequence of amino acids 13. phosphorylation of lamins causes the disassembly of the nuclear lamina and the nucleus 14. allows different metabolic processes to occur simultaneously 15. during anaphase I of meiosis, the paired chromatids are held together by a centromere and do not separate. During anaphase of mitosis, sister chromatids separate and the centromeres split. 16. helps to maintain normal cell tonicity, ensuring that cells neither shrink nor swell due to movement of water 17. UAC GUA 18. Smooth ER 19. cardiac cell (because of the large mitochondria) 20. matrix and inner mitochondrial membrane 21. all of the lysosomal enzymes are active at the acidic pH that is maintained within lysosomes but not at the neutral pH characteristic of the rest of the cytoplasm 22. prokaryotic cells lack nucleus and organelles while eukaryotic cells present both nucleus and organelles 23. receptor 24. some substances are transported in vesicles in a passive process out of a cell (exocytosis) or into a cell (endocytosis) 25. phagocytosis