Question:
What are the function of nucleus?
Answer:
- Nucleus controls all the cellular activities of the cell.
- Nucleolus is involved in synthesis of ribosomes.
- Nucleus contains hereditary information of cell.
- 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
The Fundamental Unit of Life
Q 1.
What is the plasma membrane composed of?
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.
Which cell organelle is known as 'protein factory'?
Q 4.
What is the full form of DNA and RNA?
Q 6.
What are chromosomes?
Q 7.
Why is mitochondria absent in red blood cells?
Q 8.
Is plasma membrane permeable or selectively permeable?
Q 9.
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 10.
Are plastids present in all cells? What are its types?
Q 11.
Which of the following cell is better candidate to study lysosomes?
(a) White Blood Cell
(b) Muscle Cell
Q 12.
Name the sac like structure which form the grana?
Q 13.
Which cell organelle is called 'kitchen of plant'?
Q 14.
Name the two postulates of the cell theory.
Q 15.
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 16.
Identify cell organelle and write down its name:
Digestive organelle where macromolecules are hydrolyzed
Q 17.
Who observed the cells the first time?
Q 18.
In which year electron microscope was invented?
Q 19.
Who expanded cell theory by suggesting that all cells arise from pre-existing cells?
Q 20.
Who coined the term 'protoplasm'?
Q 21.
Give examples of cells which are muti-nucleate (i.e. having many nuclei).
Q 22.
Who proposed the cell theory?
Q 23.
Name the biggest cell in human body.
Q 24.
Give an example of anucleate cell i.e. cell without nucleus.
Q 25.
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 26.
Which organ of the plant body helps in osmoregulation?
Q 27.
Which cell organelle is called 'transport system'?
Q 28.
What are the function of nucleus?
Q 29.
Identify cell organelle and write down its name:
Called 'suicide bags' of a cell.
Q 30.
Name the smallest cell in human body.
Q 31.
What are different types transport of components across cell membrane?
Q 32.
What is the thickness of cell membrane?
Q 33.
Identify cell organelle and write down its name:
Present in some animal cells, help in locomotion.
Q 34.
Give an example of cells containing two nuclei (Binucleate).
Q 36.
When chromosomes are visible in the nucleus?
Q 37.
What are the conditions for osmosis?
Q 38.
Will the temperature have any effect on the process of the osmosis?
Q 39.
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 40.
Identify cell organelle and write down its name:
Contains green colour pigment, traps light energy. Present in some plant cells.
Q 41.
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 42.
Identify cell organelle and write down its name:
Powehouse of cell
Q 43.
Who proposed fluid-mosaic model of cell or plasma membrane?
Q 44.
What is plasmolysis?
Q 45.
Who discovered nucleus in the cell?
Q 46.
Name the cell in human body which cannot reproduce.
Q 47.
Who is known as 'Father of Microscopy'?
Q 48.
Name the cell type that have internal membranes which compartmentalize their functions.
Q 49.
Identify cell organelle and write down its name:
Jelly like substance containing particles and other organelles. What is it?
Q 50.
Identify cell organelle and write down its name:
Appear brown dots either present freely in cell or bound to a membrane and make proteins.
