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.
The Fundamental Unit of Life
Q 2.
Which organelle of the cell in animals helps in osmregulation?
Q 3.
What is the full form of DNA and RNA?
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.
Who proposed the cell theory?
Q 6.
Which cell organelle is called 'kitchen of plant'?
Q 7.
What is the thickness of cell membrane?
Q 8.
Identify cell organelle and write down its name:
A tough, non-living layer, it prevents plant cells from bursting, freely permeable
Q 9.
Identify cell organelle and write down its name:
Digestive organelle where macromolecules are hydrolyzed
Q 10.
Name the two postulates of the cell theory.
Q 11.
Name the biggest cell in human body.
Q 12.
Give examples of cells which are muti-nucleate (i.e. having many nuclei).
Q 13.
What is the plasma membrane composed of?
Q 14.
Is plasma membrane permeable or selectively permeable?
Q 15.
Will the temperature have any effect on the process of the osmosis?
Q 16.
Identify cell organelle and write down its name:
Jelly like substance containing particles and other organelles. What is it?
Q 17.
In which year electron microscope was invented?
Q 18.
Name the world's smallest cell.
Q 19.
Give an example of cells containing two nuclei (Binucleate).
Q 20.
Which cell organelle is known as 'protein factory'?
Q 21.
Name the sac like structure which form the grana?
Q 22.
What are the function of nucleus?
Q 23.
Who proposed fluid-mosaic model of cell or plasma membrane?
Q 24.
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 25.
What would happen if the plasma membrane ruptures or breaks down?
Q 26.
Are plastids present in all cells? What are its types?
Q 27.
What are the components nucleus?
Q 28.
What are chromosomes?
Q 29.
Are there any exceptions to cell theory proposed by Schleiden & Schwann and Virchow? If yes, what are those?
Q 30.
Which of the following cell is better candidate to study lysosomes?
(a) White Blood Cell
(b) Muscle Cell
Q 31.
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 32.
Who expanded cell theory by suggesting that all cells arise from pre-existing cells?
Q 33.
Who coined the term 'protoplasm'?
Q 34.
When chromosomes are visible in the nucleus?
Q 35.
What are centrosomes? What functions do they perform?
Q 36.
Which cell organelle is called 'transport system'?
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.
Why is mitochondria absent in red blood cells?
Q 39.
Name the cell organelles which change energy from one form to another.
Q 40.
Identify cell organelle and write down its name:
A fluid-filled space surrounded by a membrane. Generally contains salts and sugars in plants.
Q 41.
Identify cell organelle and write down its name:
Present in some animal cells, help in locomotion.
Q 42.
Identify cell organelle and write down its name:
Called 'suicide bags' of a cell.
Q 43.
Name the cell in human body which cannot reproduce.
Q 44.
Define Osmosis. What are different types of osmosis? Give examples of osmosis.
Q 45.
What is plasmolysis?
Q 46.
What will happen if a de-shelled egg in a concentrated salt solution for 5 minutes?
Q 47.
Which organ of the plant body helps in osmoregulation?
Q 48.
What is cytoskeleton?
Q 49.
Why are lysosomes known as suicide bags?
Q 50.
Who is known as Father of Biology?
