Biology

The Fundamental Unit of Life

Question:

Are there any exceptions to cell theory proposed by Schleiden & Schwann and Virchow? If yes, what are those?

Answer:

Yes there are exceptions to cell theory. These are:
  1. Cell theory do not explain nature of Virus. They become live and multiply though they are made up of non-living material.
  2. How come the first living cell originated or how life began on the earth. (Scientists J.B.S. Haldane, Stanley L. Miller and Harold C. Urey did experiments to on this.).
  3. Mitochondria and chloroplasts have their own genetic material and can reproduce independently.
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The Fundamental Unit of Life

Q 1.

Give examples of cells which are muti-nucleate (i.e. having many nuclei).

Q 2.

What is diffusion?

Q 3.

What is the full form of DNA and RNA?

Q 4.

Who discovered Golgi apparatus?

Q 5.

Name the sac like structure which form the grana?

Q 6.

Identify cell organelle and write down its name:
Called 'suicide bags' of a cell.

Q 7.

What is plasmolysis?

Q 8.

What is the energy currency of the cell called?

Q 9.

What is osmoregulation?

Q 10.

Which organelle of the cell in animals helps in osmregulation?

Q 11.

Identify cell organelle and write down its name:
A structure involved in production of ribosomes, present inside a nucleus.

Q 12.

In which year electron microscope was invented?

Q 13.

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 14.

Who is known as Father of Biology?

Q 15.

What are the conditions for osmosis?

Q 16.

Identify cell organelle and write down its name:
Contains green colour pigment, traps light energy. Present in some plant cells.

Q 17.

Give an example of anucleate cell i.e. cell without nucleus.

Q 18.

What are chromosomes?

Q 19.

Name the smallest cell in human body.

Q 20.

Define Passive Transport.

Q 21.

Why are lysosomes known as suicide bags?

Q 22.

Which cell organelle is called 'control center'?

Q 23.

What is the function of nucleoplasm?

Q 24.

What are the function of nucleus?

Q 25.

What is the thickness of cell membrane?

Q 26.

Why is mitochondria absent in red blood cells?

Q 27.

Which of the following cell is better candidate to study lysosomes?
(a) White Blood Cell
(b) Muscle Cell

Q 28.

Identify cell organelle and write down its name:
A tough, non-living layer, it prevents plant cells from bursting, freely permeable

Q 29.

Identify cell organelle and write down its name:
Thread like structures made up of in DNA and proteins. Converts to chromosomes when cell is dividing.

Q 30.

Name the longest cell in human body.

Q 31.

Is plasma membrane permeable or selectively permeable?

Q 32.

Define Exocytosis.

Q 33.

Which organ of the plant body helps in osmoregulation?

Q 34.

Are Viruses Prokaryotic or Eukaryotic?

Q 35.

Which cell organelle is called 'kitchen of plant'?

Q 36.

Who discovered Virus?

Q 37.

Why can't single cells grow very large? Or Big organisms like human beings are multi-cellular? Why can't such big organisms be a single large cell?

Q 38.

Name the cell organelles involved in synthesis, packaging and movement of protein (or other macromolecules) inside a cell.

Q 39.

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 40.

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 41.

Identify cell organelle and write down its name:
Digestive organelle where macromolecules are hydrolyzed

Q 42.

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 43.

Identify cell organelle and write down its name:
Present in some animal cells, help in locomotion.

Q 44.

Identify cell organelle and write down its name:
Detoxify drugs and poisons specially in liver cells.

Q 45.

Define Cell

Q 46.

Name the book in which Robert Hooke published his observations about cork cells.

Q 47.

Which cell organelle is known as 'protein factory'?

Q 48.

What are the functions of Endoplasmic Reticulum (ER)?

Q 49.

What are the components nucleus?

Q 50.

What is cytoskeleton?