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 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.
Which cell organelle is called 'kitchen of plant'?
Q 4.
Is plasma membrane permeable or selectively permeable?
Q 5.
What is the plasma membrane composed of?
Q 6.
Are plastids present in all cells? What are its types?
Q 7.
What are chromosomes?
Q 8.
What is the full form of DNA and RNA?
Q 9.
Which of the following cell is better candidate to study lysosomes?
(a) White Blood Cell
(b) Muscle Cell
Q 10.
Name the two postulates of the cell theory.
Q 12.
Name the sac like structure which form the grana?
Q 13.
Why is mitochondria absent in red blood cells?
Q 14.
Name the biggest cell in human body.
Q 15.
What are different types transport of components across cell membrane?
Q 16.
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 17.
Who observed the cells the first time?
Q 18.
Which organ of the plant body helps in osmoregulation?
Q 19.
What are the function of nucleus?
Q 20.
Give an example of anucleate cell i.e. cell without 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.
Who coined the term 'protoplasm'?
Q 23.
Name the smallest cell in human body.
Q 24.
Identify cell organelle and write down its name:
Digestive organelle where macromolecules are hydrolyzed
Q 25.
Who proposed the cell theory?
Q 26.
What are the conditions for osmosis?
Q 27.
Will the temperature have any effect on the process of the osmosis?
Q 28.
Identify cell organelle and write down its name:
Powehouse of cell
Q 30.
Who proposed fluid-mosaic model of cell or plasma membrane?
Q 31.
What is plasmolysis?
Q 32.
When chromosomes are visible in the nucleus?
Q 33.
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 34.
Which cell organelle is called 'control center'?
Q 35.
Which cell organelle is called 'transport system'?
Q 36.
Identify cell organelle and write down its name:
Contains green colour pigment, traps light energy. Present in some plant cells.
Q 37.
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 38.
Identify cell organelle and write down its name:
Called 'suicide bags' of a cell.
Q 39.
In which year electron microscope was invented?
Q 40.
Who is known as 'Father of Microscopy'?
Q 41.
What is the thickness of cell membrane?
Q 42.
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 43.
Who expanded cell theory by suggesting that all cells arise from pre-existing cells?
Q 44.
Name the longest cell in human body.
Q 45.
Give an example of cells containing two nuclei (Binucleate).
Q 46.
Define Osmosis. What are different types of osmosis? Give examples of osmosis.
Q 47.
Who discovered Golgi apparatus?
Q 48.
What is Endoplasmic Reticulum(ER)? Name its types?
Q 49.
What is the function of nucleoplasm?
Q 50.
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?
