Biology

The Fundamental Unit of Life

Question:

What are the function of nucleus?

Answer:

  1. Nucleus controls all the cellular activities of the cell.
  2. Nucleolus is involved in synthesis of ribosomes.
  3. Nucleus contains hereditary information of cell.
  4. It is responsible for cell division (reproduction) and transmission of genetic information from parents to offspring.

Surface Area to Volume Ratio

Surface Area of a cube (SA) = (length x Width) x 6 Faces Volume of cube (V) = length x length length Surface Area to Volume Ratio = SA/V SA/V ratio of cube of 1 cm length = 6:1 SA/V ratio of cube of 2 cm length = 24/8 = 3:1 SA/V ratio of cube of 4 cm length = 96/64 = 1.5: 1 ⇒ SA/V ratio decreases as the sizes of the cube increases
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The Fundamental Unit of Life

Q 1.

Which cell organelle is known as 'protein factory'?

Q 2.

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

Q 3.

Is plasma membrane permeable or selectively permeable?

Q 4.

Which cell organelle is called 'kitchen of plant'?

Q 5.

What is the plasma membrane composed of?

Q 6.

Name the two postulates of the cell theory.

Q 7.

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

Q 8.

Why is mitochondria absent in red blood cells?

Q 9.

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

Q 10.

What are chromosomes?

Q 11.

What is the full form of DNA and RNA?

Q 12.

Name the biggest cell in human body.

Q 13.

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

Q 14.

Define Cell

Q 15.

Name the sac like structure which form the grana?

Q 16.

Who observed the cells the first time?

Q 17.

Who proposed the cell theory?

Q 18.

Name the smallest cell in human body.

Q 19.

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

Q 20.

What are the function of nucleus?

Q 21.

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 22.

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

Q 23.

What are different types transport of components across cell membrane?

Q 24.

What is plasmolysis?

Q 25.

What are the conditions for osmosis?

Q 26.

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 27.

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

Q 28.

Who coined the term 'protoplasm'?

Q 29.

What is diffusion?

Q 30.

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

Q 31.

Which organ of the plant body helps in osmoregulation?

Q 32.

Which cell organelle is called 'control center'?

Q 33.

In which year electron microscope was invented?

Q 34.

Who proposed fluid-mosaic model of cell or plasma membrane?

Q 35.

Who discovered Golgi apparatus?

Q 36.

When chromosomes are visible in the nucleus?

Q 37.

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 38.

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

Q 39.

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

Q 40.

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

Q 41.

Who is known as 'Father of Microscopy'?

Q 42.

What are the components nucleus?

Q 43.

What is the function of nucleoplasm?

Q 44.

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 45.

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

Q 46.

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

Q 47.

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 48.

Name the longest cell in human body.

Q 49.

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

Q 50.

Why are lysosomes known as suicide bags?