Question 1: Indicate whether the following statements are True (T) or False (F).
Answer: (a) True, (b) True, (c) False, (d) True
Question 2: Make a sketch of the human nerve cell. What function do nerve cells perform?
Answer: Nerve cells carry signals between organs and brain.
Question 3: Write short notes on the following: (a) Cytoplasm (b) Nucleus of a cell
Question 4: Which part of the cell contains organelles?
Answer: Cytoplasm
Question 5: Make sketches of animal and plant cells. State three differences between them.
Answer:
Difference Between Plant Cell and Animal Cell | |
---|---|
Plant Cell | Animal Cell |
Cell wall is present. | Cell wall is absent. |
Chloroplast is present. | Chloroplast is absent. |
Vacuoles are large. | Vacuoles are much smaller or absent. |
Question 6: State the difference between eukaryotes and prokaryotes.
Answer:
Prokaryotes | Eukaryotes |
---|---|
Nucleus is absent. | Nucleus is present. |
All are unicellular. | Can be unicellular and multicellular. |
Examples: Bacteria and blue-green algae | Examples: man, lion, horse, etc. |
Question 7: Where are chromosomes found in a cell? State their function.
Answer: Chromosomes are found inside the nucleus. Chromosomes are responsible for inheritance of characters from one generation to the next generation.
Question 8: ‘Cells are the basic structural units of living organisms’. Explain.
Answer: All organisms are made up of cells. The way a building is made up of bricks, an organism is made up of cells. Many cells group together to make a tissue, many tissues come together to make an organ, many organs come together to make an organ system and many organ systems make an organism. Thus, it is clear that cells are the basic structural units of living organisms.
Question 9: Explain why chloroplasts are found only in plant cells?
Answer: Chloroplast contains a green pigment called chlorophyll. Photosynthesis takes place in chloroplast. We know that green plants are capable of photosynthesis but animals do not have this capability. Hence, chloroplasts are found only in plant cells.
Copyright © excellup 2014