1. What is Chromatin material and how does it change just before the cell division? 2. Write two similarities and one dissimilarity between mitochondria and plastid. 3. Distinguish between cell wall and cell membrane. 4. Give reason for the following: a) Plastids are able to make their own proteins. b) Growth in plants is restricted to certain regions. c) Epidermal cells of the roots generally have hair like parts. 5. List two points of differences between parenchyma and sclerenchyma. 6. a) Voluntary muscles are also known as skeletal muscles. Justify b) Give two structural characteristics of these voluntary muscles. 7. Animals of colder region and fishes of cold water have thicker layer of subcutaneous fat. Explain why? 8. How does a cell wall help a plant to withstand hypotonic external media without bursting? 9. Write a short note on connective tissue. 10. The quantity and the quality of the food is decreasing day by day. As population is increasing drastically, mention the steps taken to improve this condition. 11. List the constituents of phloem. What will happen if the phloem at the base of a branch is removed? 12. Write a note on protective tissue in plant. 13. How do you think meristematic tissues are important for the plants? 14. Explain how the crop variety improvement is necessary and give one example (research based question) 15. What is a nervous tissue? Explain the structure of a neuron with a diagram. What functions do they perform in our body?
Answers
Answer: 1) Chromatin is a substance within a chromosome consisting of DNA and protein. it change when The DNA carries the cell's genetic instructions and the major proteins in chromatin are hi-stones, which help package the DNA in a compact form that fits in the cell nucleus.
2)these are the similarities:Presence of double membrane envelope.
(2)Formation of involutions from the inner membrane.
(3)Both are semi-autonomous.
(4)DNA is naked in both.
(5)Take part in energy transduction.
(6)Both of them produce ATP.
number 3:Cell wall is completely permeable to ordinary macromolecules . Cell membrane is selectively permeable or semi- permeable allowing only certain molecules to pass through. Cell wall determines the cell shape and offers protection. please this is the one i know