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.
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 2.
Name the two postulates of the cell theory.
Q 3.
What is the plasma membrane composed of?
Q 4.
Which of the following cell is better candidate to study lysosomes?
(a) White Blood Cell
(b) Muscle Cell
Q 6.
What is the full form of DNA and RNA?
Q 7.
Identify cell organelle and write down its name:
A tough, non-living layer, it prevents plant cells from bursting, freely permeable
Q 8.
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 9.
Identify cell organelle and write down its name:
Digestive organelle where macromolecules are hydrolyzed
Q 10.
Name the cell organelles which change energy from one form to another.
Q 11.
Identify cell organelle and write down its name:
Jelly like substance containing particles and other organelles. What is it?
Q 12.
Is plasma membrane permeable or selectively permeable?
Q 13.
Are plastids present in all cells? What are its types?
Q 14.
Name the cell type that have internal membranes which compartmentalize their functions.
Q 15.
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 16.
Will the temperature have any effect on the process of the osmosis?
Q 17.
Which cell organelle is called 'kitchen of plant'?
Q 18.
What are chromosomes?
Q 19.
Identify cell organelle and write down its name:
Present in some animal cells, help in locomotion.
Q 20.
Name the biggest cell in human body.
Q 21.
What will happen if a de-shelled egg in a concentrated salt solution for 5 minutes?
Q 22.
Name the sac like structure which form the grana?
Q 23.
What is the thickness of cell membrane?
Q 24.
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 25.
Who expanded cell theory by suggesting that all cells arise from pre-existing cells?
Q 26.
In which year electron microscope was invented?
Q 27.
Who coined the term 'protoplasm'?
Q 28.
Which cell organelle is known as 'protein factory'?
Q 29.
Which organelle of the cell in animals helps in osmregulation?
Q 30.
What is cytoskeleton?
Q 31.
Identify cell organelle and write down its name:
Powehouse of cell
Q 32.
Define Passive Transport.
Q 33.
What would happen if the plasma membrane ruptures or breaks down?
Q 34.
What is the energy currency of the cell called?
Q 35.
Why is mitochondria absent in red blood cells?
Q 36.
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 37.
Who observed the cells the first time?
Q 38.
Name the smallest cell in human body.
Q 39.
Name the cell in human body which cannot reproduce.
Q 40.
Give an example of cells containing two nuclei (Binucleate).
Q 41.
Give examples of cells which are muti-nucleate (i.e. having many nuclei).
Q 42.
Which organ of the plant body helps in osmoregulation?
Q 43.
What are centrosomes? What functions do they perform?
Q 44.
Which cell organelle is called 'transport system'?
Q 45.
What are the functions of Endoplasmic Reticulum (ER)?
Q 46.
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 47.
Name the world's smallest cell.
Q 48.
Define Osmosis. What are different types of osmosis? Give examples of osmosis.
Q 49.
Who is known as 'Father of Microscopy'?
Q 50.
Identify cell organelle and write down its name:
A fluid-filled space surrounded by a membrane. Generally contains salts and sugars in plants.
