Biology

The Fundamental Unit of Life

Question:

What are chromosomes?

Answer:

Chromosomes are compact rod like bodies, which are formed at the time of cell division from chromatin material. They are made up of DNA and carry genes (unit of inheritance).
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Questions and Answers

The Fundamental Unit of Life

Q 1.

What is the full form of DNA and RNA?

Q 2.

Which organelle of the cell in animals helps in osmregulation?

Q 3.

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 4.

Define Cell

Q 5.

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

Q 6.

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 7.

What will happen if a de-shelled egg in a concentrated salt solution for 5 minutes?

Q 8.

Name the sac like structure which form the grana?

Q 9.

What is the plasma membrane composed of?

Q 10.

Which cell organelle is known as 'protein factory'?

Q 11.

When chromosomes are visible in the nucleus?

Q 12.

Which cell organelle is called 'kitchen of plant'?

Q 13.

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

Q 14.

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

Q 15.

Name the two postulates of the cell theory.

Q 16.

What are the components nucleus?

Q 17.

Identify cell organelle and write down its name:
Jelly like substance containing particles and other organelles. What is it?

Q 18.

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

Q 19.

Who observed the cells the first time?

Q 20.

Name the biggest cell in human body.

Q 21.

Is plasma membrane permeable or selectively permeable?

Q 22.

What are the function of nucleus?

Q 23.

What is the thickness of cell membrane?

Q 24.

Identify cell organelle and write down its name:
A fluid-filled space surrounded by a membrane. Generally contains salts and sugars in plants.

Q 25.

Who coined the term 'protoplasm'?

Q 26.

What are different types transport of components across cell membrane?

Q 27.

Place a de-shelled egg in water for five minutes. What do you observe? (Note: De-shelled egg means,the shell of an egg is removed by dissolving it in dilute hydrochloric acid. The shell is mostly calcium carbonate. A thin outer skin now encloses the egg.)

Q 28.

Who is known as Father of Biology?

Q 29.

Are plastids present in all cells? What are its types?

Q 30.

What are the conditions for osmosis?

Q 31.

Will the temperature have any effect on the process of the osmosis?

Q 32.

Which organ of the plant body helps in osmoregulation?

Q 33.

What are the functions of Endoplasmic Reticulum (ER)?

Q 34.

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

Q 35.

Why is mitochondria absent in red blood cells?

Q 36.

In which year electron microscope was invented?

Q 37.

Name the smallest cell in human body.

Q 38.

Define Osmosis. What are different types of osmosis? Give examples of osmosis.

Q 39.

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 40.

What is osmoregulation?

Q 41.

What are centrosomes? What functions do they perform?

Q 42.

What are chromosomes?

Q 43.

Name the cell type that have internal membranes which compartmentalize their functions.

Q 44.

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

Q 45.

Identify cell organelle and write down its name:
A partially permeable layer prevents cell contents from escaping controls what substances enter and leave the cell. Identify?

Q 46.

Identify cell organelle and write down its name:
Powehouse of cell

Q 47.

Who expanded cell theory by suggesting that all cells arise from pre-existing cells?

Q 48.

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

Q 49.

Who discovered nucleus in the cell?

Q 50.

Name the world's smallest cell.