Question:
Why are lysosomes known as suicide bags?
Answer:
Lysosomes are organelles that contain digestive enzymes. They digest excess or worn out organelles, food particles, and engulfed viruses or bacteria. Lysosomes fuse with vacuoles and dispense their enzymes into the vacuole, digesting its contents. Sometimes, lysosomes digest the cells that contain them. It happens when cells get damaged or destroyed. That's why lysosomes are called suicidal bags.
E.g. When a tadpole develops into a frog, lysosomes within the cells of the tadpole's tail cause its digestion. Or Lysosomes help in defense by digesting germs, as in white blood cells.
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 world's smallest cell.
Q 12.
Name the biggest cell in human body.
Q 13.
Give examples of cells which are muti-nucleate (i.e. having many nuclei).
Q 14.
What is the plasma membrane composed of?
Q 15.
Is plasma membrane permeable or selectively permeable?
Q 16.
Will the temperature have any effect on the process of the osmosis?
Q 17.
Identify cell organelle and write down its name:
Jelly like substance containing particles and other organelles. What is it?
Q 18.
In which year electron microscope was invented?
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 coined the term 'protoplasm'?
Q 24.
Who proposed fluid-mosaic model of cell or plasma membrane?
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.
What would happen if the plasma membrane ruptures or breaks down?
Q 27.
Are plastids present in all cells? What are its types?
Q 28.
What are the components nucleus?
Q 29.
What are chromosomes?
Q 30.
Are there any exceptions to cell theory proposed by Schleiden & Schwann and Virchow? If yes, what are those?
Q 31.
Which of the following cell is better candidate to study lysosomes?
(a) White Blood Cell
(b) Muscle Cell
Q 32.
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 33.
Identify cell organelle and write down its name:
Called 'suicide bags' of a cell.
Q 34.
Who expanded cell theory by suggesting that all cells arise from pre-existing cells?
Q 35.
When chromosomes are visible in the nucleus?
Q 36.
What are centrosomes? What functions do they perform?
Q 37.
Which cell organelle is called 'transport system'?
Q 38.
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 39.
Why is mitochondria absent in red blood cells?
Q 40.
What is cytoskeleton?
Q 41.
Name the cell organelles which change energy from one form to another.
Q 42.
Identify cell organelle and write down its name:
A fluid-filled space surrounded by a membrane. Generally contains salts and sugars in plants.
Q 43.
Identify cell organelle and write down its name:
Present in some animal cells, help in locomotion.
Q 44.
Name the cell in human body which cannot reproduce.
Q 45.
Define Osmosis. What are different types of osmosis? Give examples of osmosis.
Q 46.
What is plasmolysis?
Q 47.
What will happen if a de-shelled egg in a concentrated salt solution for 5 minutes?
Q 48.
Who is known as Father of Biology?
Q 49.
Which organ of the plant body helps in osmoregulation?
Q 50.
What are the functions of Endoplasmic Reticulum (ER)?
