Question:
What are centrosomes? What functions do they perform?
Answer:
Centrosome is a small, star shaped protoplamic organelle and is present near to nucleus. In animal cells, it consists of two small granules called centrioles. These centrioles are orthogonally arranged i.e. lie at right angles to each other. In plant cells, centrioles are absent.
Functions of Centrosomes:
- Initiate cell division
- During cell division, centrioles move to opposite poles of the cell and help in spindle formation.
- They form basal bodies (microtubules like sturtures) which form cillia or flagella.
The Fundamental Unit of Life
Q 1.
Which cell organelle is known as 'protein factory'?
Q 2.
Are plastids present in all cells? What are its types?
Q 3.
Identify cell organelle and write down its name:
A tough, non-living layer, it prevents plant cells from bursting, freely permeable
Q 4.
Is plasma membrane permeable or selectively permeable?
Q 6.
What is the plasma membrane composed of?
Q 7.
Which cell organelle is called 'kitchen of plant'?
Q 8.
Identify cell organelle and write down its name:
A network of flattened cavities surrounded by a membrane, which links with the nuclear membrane. Help in packaging proteins.
Q 9.
Identify cell organelle and write down its name:
Slipper or oval shaped, its inner membrane is multi-folded and has lot of chemical activity
Q 10.
Which of the following cell is better candidate to study lysosomes?
(a) White Blood Cell
(b) Muscle Cell
Q 11.
Name the two postulates of the cell theory.
Q 12.
Give an example of anucleate cell i.e. cell without nucleus.
Q 13.
What are different types transport of components across cell membrane?
Q 14.
What is the full form of DNA and RNA?
Q 15.
Will the temperature have any effect on the process of the osmosis?
Q 16.
What are the function of nucleus?
Q 17.
Why is mitochondria absent in red blood cells?
Q 18.
Name the biggest cell in human body.
Q 19.
Name the sac like structure which form the grana?
Q 20.
What are chromosomes?
Q 22.
What are the conditions for osmosis?
Q 23.
Who proposed fluid-mosaic model of cell or plasma membrane?
Q 24.
Which organ of the plant body helps in osmoregulation?
Q 25.
Name the smallest cell in human body.
Q 26.
Who expanded cell theory by suggesting that all cells arise from pre-existing cells?
Q 27.
Identify cell organelle and write down its name:
Powehouse of cell
Q 28.
Who observed the cells the first time?
Q 29.
Name the cell type that have internal membranes which compartmentalize their functions.
Q 30.
Identify cell organelle and write down its name:
Membrane-bound vesicles arranged approximately parallel to each other. Active in synthesis, modification, sorting, and Secretion of cell products
Q 31.
Identify cell organelle and write down its name:
Called 'suicide bags' of a cell.
Q 32.
Identify cell organelle and write down its name:
Detoxify drugs and poisons specially in liver cells.
Q 33.
Who coined the term 'protoplasm'?
Q 34.
Who is known as 'Father of Microscopy'?
Q 35.
What is the thickness of cell membrane?
Q 36.
Identify cell organelle and write down its name:
Digestive organelle where macromolecules are hydrolyzed
Q 37.
Who proposed the cell theory?
Q 38.
Put dried raisins in plain water and leave them for some time. Then place them in concentrated solution of sugar or salt. What do you observe in both cases?
Q 39.
Who is known as Father of Biology?
Q 40.
Are Viruses Prokaryotic or Eukaryotic?
Q 41.
Identify cell organelle and write down its name:
Present in some animal cells, help in locomotion.
Q 42.
In which year electron microscope was invented?
Q 43.
Name the longest cell in human body.
Q 44.
Who discovered Golgi apparatus?
Q 45.
When chromosomes are visible in the nucleus?
Q 46.
Which cell organelle is called 'control center'?
Q 47.
What are the components nucleus?
Q 48.
Who discovered Virus?
Q 49.
Name the cell organelles involved in synthesis, packaging and movement of protein (or other macromolecules) inside a cell.
Q 50.
Identify cell organelle and write down its name:
A fluid-filled space surrounded by a membrane. Generally contains salts and sugars in plants.
