Biology

The Fundamental Unit of Life

Question:

What is diffusion?

Answer:

Diffusion is the net movement of molecules from high to regions of lower concentration as a result of random molecular motion. Diffusion tends to distribute molecules uniformly. Exchange of gases like CO2 and O2 in lungs, plants, blood cells, O2 entering stomata of leaves are examples of diffusion. Diffusion is passive transport i.e. no external energy is provided for the movement of molecules. The natural kinetic energy of the particle supplies the energy.
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The Fundamental Unit of Life

Q 1.

What is the full form of DNA and RNA?

Q 2.

Define Cell

Q 3.

Which organelle of the cell in animals helps in osmregulation?

Q 4.

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 5.

Which cell organelle is called 'kitchen of plant'?

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.

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

Q 8.

Name the sac like structure which form the grana?

Q 9.

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

Q 10.

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

Q 11.

Name the biggest cell in human body.

Q 12.

Give an example of cells containing two nuclei (Binucleate).

Q 13.

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

Q 14.

Which cell organelle is known as 'protein factory'?

Q 15.

What are chromosomes?

Q 16.

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

Q 17.

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

Q 18.

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

Q 19.

Is plasma membrane permeable or selectively permeable?

Q 20.

What are different types transport of components across cell membrane?

Q 21.

When chromosomes are visible in the nucleus?

Q 22.

What are centrosomes? What functions do they perform?

Q 23.

What are the functions of Endoplasmic Reticulum (ER)?

Q 24.

What are the components nucleus?

Q 25.

What is the thickness of cell membrane?

Q 26.

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

Q 27.

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

Q 28.

Who observed the cells the first time?

Q 29.

Who proposed the cell theory?

Q 30.

Name the world's smallest cell.

Q 31.

What is the plasma membrane composed of?

Q 32.

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 33.

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

Q 34.

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

Q 35.

Which organ of the plant body helps in osmoregulation?

Q 36.

What are the function of nucleus?

Q 37.

In which year electron microscope was invented?

Q 38.

Name the smallest cell in human body.

Q 39.

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

Q 40.

What would happen if the plasma membrane ruptures or breaks down?

Q 41.

Who is known as Father of Biology?

Q 42.

Who discovered Golgi apparatus?

Q 43.

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 44.

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

Q 45.

Name the cell organelles which change energy from one form to another.

Q 46.

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

Q 47.

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 48.

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

Q 49.

Name the two postulates of the cell theory.

Q 50.

Who is known as 'Father of Microscopy'?