H. Answer the following questions in detail.
1. What are the features that make a cell from a plant body different from that of an animal?
Explain with the help of diagrams.
2. Write a brief account of the nucleus also termed as the brain of the cell.
3. What is a plastid? What are its types? Explain its function in the organism where it is found.
Answers
Answer :-
1. Features that make a plant cell different from that of an animal cell are -
=> Cell wall - It is only present in the plant cell, not in animal cell.
=> Vacuoles - These are present in both plant cell and animal cell. But vacuoles in plant cell are large and prominent whereas vacuoles in animal cell are small and temporary.
=> Plastids - These are present only in plant cell not in animal cells.
=> Centrosome - These are absent in a plant cell whereas it is present in animal cell.
Diagram - in attachment.
2. Nucleus is a large spherical body, surrounded by a double layered nuclear membrane with nuclear pores, which lies in the center of the cytoplasm. It contains a network of coloured fibres which is known as chromatin fibres. Nucleus also known as the brain of the cell because it regulates all cell functions and if it is removed, the cell will die.
3. Plastids are double-membraned and proteinceous organelles which are found in the plant cells. It is of three types :-
=> Chloroplasts - It green in colour. It contains the pigment chlorophyll. It traps solar energy for photosynthesis.
=> Leucoplasts - It is colourless. It contains no pigment. It stores starch.
=> Chlomoplasts - It is of various colours. It contains the pigment Xanthophyll and Carotene. It imparts colours to flowers and fruits.
