Animal and Plant Cells Lesson | KS3 Biology | RevisionTown

1. What are the basic characteristics of all living cells?

Answer: All living cells share basic characteristics, including having a cell membrane, cytoplasm, genetic material (DNA/RNA), and the ability to perform essential life processes such as metabolism, growth, and reproduction.

2. What are the similarities between animal and plant cells?

Answer: Both animal and plant cells have:

• Nucleus: Controls cell activities and contains genetic material.
• Cytoplasm: Jelly-like substance where chemical reactions occur.
• Cell membrane: Controls the movement of substances into and out of the cell.
• Mitochondria: Sites of cellular respiration, which releases energy.

3. What unique structures are found in plant cells?

Answer: Unique structures in plant cells include:

• Cell wall: Rigid outer layer made of cellulose, providing strength and support.
• Vacuole: Large central space filled with cell sap, aiding in maintaining cell structure and storing nutrients.
• Chloroplasts: Contain chlorophyll and are the site of photosynthesis.

4. What is the function of the nucleus in a cell?

Answer: The nucleus controls cell activities, stores genetic information, and regulates gene expression and cell division.

5. How does the cytoplasm function in a cell?

Answer: The cytoplasm is a jelly-like substance that houses organelles and is the site of numerous chemical reactions necessary for the cell’s survival and function.

6. What role does the cell membrane play in a cell?

Answer: The cell membrane controls the movement of substances into and out of the cell, providing a barrier that maintains the internal environment of the cell.

7. Why are mitochondria important in cells?

Answer: Mitochondria are the powerhouse of the cell, where cellular respiration occurs, releasing energy in the form of ATP that the cell uses for various activities.

8. What is the purpose of the cell wall in plant cells?

Answer: The cell wall provides structural support, protection, and rigidity to plant cells, helping them maintain their shape.

9. How do vacuoles function in plant cells?

Answer: Vacuoles store nutrients, waste products, and help maintain turgor pressure, which supports the plant cell’s structure and rigidity.

10. What is the significance of chloroplasts in plant cells?

Answer: Chloroplasts contain chlorophyll and are the site of photosynthesis, where light energy is converted into chemical energy in the form of glucose.

11. Can animal cells perform photosynthesis?

Answer: No, animal cells do not have chloroplasts and therefore cannot perform photosynthesis.

12. Do plant cells have mitochondria?

Answer: Yes, plant cells have mitochondria to perform cellular respiration, in addition to chloroplasts for photosynthesis.

13. What types of cells are eukaryotic?

Answer: Both animal and plant cells are eukaryotic, meaning they have a nucleus and other membrane-bound organelles.

14. What is the main difference between prokaryotic and eukaryotic cells?

Answer: Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and membrane-bound organelles.

15. How can cells be viewed under a microscope?

Answer: Cells can be viewed under a microscope by placing them on a slide, staining them to enhance contrast, and using the microscope’s lenses to magnify the image.

16. What is the function of ribosomes in cells?

Answer: Ribosomes are the site of protein synthesis, where genetic information is translated to build proteins necessary for cell function.

17. Do plant cells have lysosomes?

Answer: Plant cells have similar structures to lysosomes, such as vacuoles containing digestive enzymes, but they do not have lysosomes as commonly found in animal cells.

18. What are peroxisomes, and what do they do?

Answer: Peroxisomes are organelles that contain enzymes to break down fatty acids and detoxify harmful substances, playing a role in metabolism.

19. What is the function of the endoplasmic reticulum (ER) in cells?

Answer: The ER is involved in protein and lipid synthesis, with rough ER being studded with ribosomes for protein synthesis and smooth ER being involved in lipid synthesis and detoxification.

20. How does the Golgi apparatus function in cells?

Answer: The Golgi apparatus modifies, sorts, and packages proteins and lipids for transport to different parts of the cell or for secretion outside the cell.

21. What are vesicles, and what is their role in cells?

Answer: Vesicles are small membrane-bound sacs that transport materials within the cell, including proteins, lipids, and waste products.

22. How do plant cells differ in shape from animal cells?

Answer: Plant cells typically have a fixed, rectangular shape due to their rigid cell wall, while animal cells have a more flexible and varied shape.

23. What is the function of the cytoskeleton in cells?

Answer: The cytoskeleton provides structural support, helps in cell movement, and aids in the transport of materials within the cell.

24. Do animal cells have a cell wall?

Answer: No, animal cells do not have a cell wall. They only have a cell membrane.

25. What is the function of plasmodesmata in plant cells?

Answer: Plasmodesmata are channels that connect plant cells, allowing the transport of materials and communication between cells.

26. What is the role of the cell sap in the vacuole of plant cells?

Answer: Cell sap helps maintain pressure inside the vacuole, supporting the cell structure and storing nutrients, waste products, and other substances.

27. How do cells in multicellular organisms differ from single-celled organisms?

Answer: Cells in multicellular organisms are specialized to perform specific functions and work together, while single-celled organisms perform all life processes within one cell.

28. What is the function of chlorophyll in chloroplasts?

Answer: Chlorophyll captures light energy, which is then used in photosynthesis to convert carbon dioxide and water into glucose and oxygen.

29. Can plant cells survive without sunlight?

Answer: Plant cells need sunlight for photosynthesis to produce energy, but they can survive for some time by using stored energy or through cellular respiration.

30. What is cellular respiration, and where does it occur in cells?

Answer: Cellular respiration is the process by which cells convert glucose and oxygen into energy (ATP), carbon dioxide, and water. It occurs in the mitochondria.

31. How do animal cells obtain energy?

Answer: Animal cells obtain energy by consuming food, which is broken down into glucose and other nutrients. These nutrients are then used in cellular respiration to produce ATP.

32. What are the main differences between plant and animal cells?

Answer: The main differences are:

• Plant cells have a cell wall, chloroplasts, and a large central vacuole.
• Animal cells lack a cell wall and chloroplasts and have smaller, multiple vacuoles.

33. Do plant cells have centrioles?

Answer: Most plant cells lack centrioles, which are typically found in animal cells and are involved in cell division.

34. How do plant cells contribute to photosynthesis?

Answer: Plant cells with chloroplasts carry out photosynthesis, producing glucose and oxygen from carbon dioxide and water using light energy.

35. What is the function of the nucleolus in a cell?

Answer: The nucleolus is located within the nucleus and is responsible for producing and assembling ribosome components.

36. How do cells communicate with each other?

Answer: Cells communicate through chemical signals, such as hormones and neurotransmitters, and through direct connections like plasmodesmata in plant cells and gap junctions in animal cells.

37. What is the function of the nuclear membrane?

Answer: The nuclear membrane encloses the nucleus, protecting the genetic material and regulating the exchange of substances between the nucleus and cytoplasm.

38. What role do lysosomes play in animal cells?

Answer: Lysosomes contain digestive enzymes that break down waste materials, cellular debris, and foreign invaders, playing a crucial role in cellular cleanup and recycling.

39. How do cells maintain homeostasis?

Answer: Cells maintain homeostasis by regulating the movement of substances across the cell membrane, managing metabolic processes, and responding to changes in the environment.

40. What are the different types of plastids found in plant cells?

Answer: Plastids include chloroplasts (photosynthesis), chromoplasts (pigment synthesis), and leucoplasts (storage of starch, oils, and proteins).

41. How do plant cells store energy?

Answer: Plant cells store energy in the form of starch, which is stored in plastids like amyloplasts, and in the central vacuole as sugars and other compounds.

42. What is endocytosis and exocytosis in cells?

Answer: Endocytosis is the process by which cells engulf external substances by enclosing them in a membrane, while exocytosis is the process of expelling substances from the cell by fusing vesicles with the cell membrane.

43. How do cells repair and replace damaged parts?

Answer: Cells repair and replace damaged parts through processes like autophagy (breaking down and recycling cellular components) and mitosis (cell division).

44. What is the significance of cell differentiation in multicellular organisms?

Answer: Cell differentiation allows cells to specialize and perform specific functions, contributing to the overall functioning and complexity of multicellular organisms.

45. How do cells respond to external stimuli?

Answer: Cells respond to external stimuli through signal transduction pathways, where receptors on the cell surface detect signals and initiate a response within the cell.

46. What are microtubules and microfilaments in the cytoskeleton?

Answer: Microtubules are hollow tubes that provide structural support and help in cell division and transport, while microfilaments are thin, thread-like structures involved in cell movement and shape maintenance.

47. How do cells undergo division?

Answer: Cells divide through processes like mitosis (for growth and repair) and meiosis (for producing gametes in sexual reproduction).

48. What is the function of the Golgi apparatus in protein modification?

Answer: The Golgi apparatus modifies, sorts, and packages proteins synthesized in the ER for transport to their final destinations inside or outside the cell.

49. How do plant cells contribute to the carbon cycle?

Answer: Plant cells contribute to the carbon cycle by absorbing carbon dioxide during photosynthesis and releasing it during respiration, helping to regulate atmospheric carbon levels.

50. What is the role of ATP in cells?

Answer: ATP (adenosine triphosphate) is the primary energy carrier in cells, providing energy for various cellular processes, including metabolism, transport, and cell division.