Q.1. what are the various level of organisation in multicellular organism?
Ans: Cell performs similar functions are grouped into Tissue. A group of tissue that perform special functions are called organ. A group of organ is called organ system. Organ system work together and form organism
Q.2. Give two examples to explain there exist relation between cell shape and function?
Ans: The nerve cell cells are branched that help them to send message over longer distances. White blood cells have irregular shape as they have to move in different parts of tissue.
Q.3. Why mitochondria is called power house of cell?
Ans: Mitochondria is called power house of cell because it release energy by the oxidation of food.
Q.4. Why is Lysosomes called suicide bag?
Ans: When cell get damaged Lysosomes may burst and destroy the cell. For this activity Lysosomes are called suicide bag.
Q.5.Write the functions of: cell wall, cell membrane, chromosomes and cytoplasm
Ans: cell wall – Provide rigidity, shape and protection to plant cells.
cell membrane: It separate cell from surrounding and allow the moment of some substance.
Chromosomes: They carry hereditary information from parent to children
Cytoplasm : All chemical rection and function takes place here.
Q.6. Describe the part of the nucleus of cell?
Ans: Nucleus is a dense round spherical body in the centre of a cell. It was discovered by Robert brown in 1831. Nucleus is covered with a double layer porous covering called nuclear membrane. The dense fluid like substance present inside the nucleus i is called Nucleoplasm. There is a dense round spherical body in the centre of Nucleus is called the nucleolus which contains RNA.
Chromosomes are condensed form of the fine thread like structure in side nucleus called chromatin material (thread) which are seen only cell undergoing cell division. The chromatin thread are made up of DNA which organize into gene
Q.7. Distinguish between prokaryotic and eukaryotic?
- They are mainly unicellular
- Nuclear material is not surrounded by nuclear membrane
- They have only a few organelles
- DNA is circular
- DNA lies in the cytoplasm (Nucleus absent)
- Cell division occurs mostly through binary fission
- They are mainly multicellular except for Protista
- Nuclear material is surrounded by nuclear membrane
- Many organelles
- DNA is linear
- DNA is inside the nucleus
- Mitosis, meiosis or both take place.
Q.8. What are cell organelles. Give three examples?
Ans: Membrane bound structures present in the cytoplasm that perform specific functions are called cell organelles like mitochondria, Lysosomes, Golgi bodies.
Q.9. Why was cell discovered after the discovery of microscope?
Ans: cell was discovered after the discovery of microscope because cell is microscopic and cannot be seen by naked eyes.
Q.10. why plant cell have call wall but animal cell do not?
Ans: plants do not move from one place to another. Plant cells have cell wall that helps the plant to have a fixed shape and protect it from injury. The cell wall if present in the animal cell, they will not show movement.
Q11. Raghav viewed a slide under microscope: it had a cell wall and chloroplast. Was he viewing a slide of animal or plant cell?
Ans: plant cell
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