Question:
Define Osmosis. What are different types of osmosis? Give examples of osmosis.
Answer:
Osmosis is a special type of diffusion i.e. passage of water (solvent) across a selectively permeable membrane, from a region of high water concentration (dilute solution) to the region of low water concentration (concentrated solution). Osmosis is also a passive transport i.e. no external energy is required for the passage. There are two type of osmosis:
- Endosmosis: The process in which the water molecules enter into the cell is known as endosmosis.
- Exosmosis: The process in which the water molecules move out of the cell is known as exosmosis.
Examples of Osmosis are:
- Absorption of water by plant roots.
- Absorption of water by alimentary canal.
- Re-absorption of water by tubules of the nephron in kidneys.
The Fundamental Unit of Life
Q 1.
Name the sac like structure which form the grana?
Q 2.
Identify cell organelle and write down its name:
Called 'suicide bags' of a cell.
Q 4.
What is the full form of DNA and RNA?
Q 5.
Give examples of cells which are muti-nucleate (i.e. having many nuclei).
Q 6.
What are the function of nucleus?
Q 7.
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 8.
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 9.
Who discovered nucleus in the cell?
Q 10.
Who discovered Golgi apparatus?
Q 11.
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 12.
Identify cell organelle and write down its name:
A tough, non-living layer, it prevents plant cells from bursting, freely permeable
Q 13.
Identify cell organelle and write down its name:
Powehouse of cell
Q 14.
Give an example of anucleate cell i.e. cell without nucleus.
Q 15.
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 16.
What is the energy currency of the cell called?
Q 17.
What are the components nucleus?
Q 18.
What is the function of nucleoplasm?
Q 19.
Name the cell organelles involved in synthesis, packaging and movement of protein (or other macromolecules) inside a cell.
Q 21.
Define Passive Transport.
Q 22.
What are the conditions for osmosis?
Q 23.
Which organelle of the cell in animals helps in osmregulation?
Q 24.
Identify cell organelle and write down its name:
Detoxify drugs and poisons specially in liver cells.
Q 25.
In which year electron microscope was invented?
Q 27.
Are plastids present in all cells? What are its types?
Q 28.
Which cell organelle is called 'kitchen of plant'?
Q 29.
What are chromosomes?
Q 30.
Who discovered Virus?
Q 31.
Why is mitochondria absent in red blood cells?
Q 32.
Which of the following cell is better candidate to study lysosomes?
(a) White Blood Cell
(b) Muscle Cell
Q 33.
Identify cell organelle and write down its name:
Appear brown dots either present freely in cell or bound to a membrane and make proteins.
Q 34.
Name the smallest cell in human body.
Q 35.
Name the longest cell in human body.
Q 36.
Who proposed fluid-mosaic model of cell or plasma membrane?
Q 37.
Is plasma membrane permeable or selectively permeable?
Q 38.
What would happen if the plasma membrane ruptures or breaks down?
Q 39.
Why are lysosomes known as suicide bags?
Q 40.
What is osmoregulation?
Q 41.
Which cell organelle is called 'control center'?
Q 42.
Are there any exceptions to cell theory proposed by Schleiden & Schwann and Virchow? If yes, what are those?
Q 43.
Identify cell organelle and write down its name:
Jelly like substance containing particles and other organelles. What is it?
Q 44.
Identify cell organelle and write down its name:
A fluid-filled space surrounded by a membrane. Generally contains salts and sugars in plants.
Q 45.
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 46.
Identify cell organelle and write down its name:
Present in some animal cells, help in locomotion.
Q 47.
Identify cell organelle and write down its name:
A structure involved in production of ribosomes, present inside a nucleus.
Q 48.
Name the book in which Robert Hooke published his observations about cork cells.
Q 49.
Define Osmosis. What are different types of osmosis? Give examples of osmosis.
Q 50.
What is plasmolysis?
