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 1.
What is the plasma membrane composed of?
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 known as 'protein factory'?
Q 4.
What is the full form of DNA and RNA?
Q 6.
What are chromosomes?
Q 7.
Why is mitochondria absent in red blood cells?
Q 8.
Is plasma membrane permeable or selectively permeable?
Q 9.
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 10.
Are plastids present in all cells? What are its types?
Q 11.
Which of the following cell is better candidate to study lysosomes?
(a) White Blood Cell
(b) Muscle Cell
Q 12.
Name the sac like structure which form the grana?
Q 13.
Which cell organelle is called 'kitchen of plant'?
Q 14.
Identify cell organelle and write down its name:
Digestive organelle where macromolecules are hydrolyzed
Q 15.
Name the two postulates of the cell theory.
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.
In which year electron microscope was invented?
Q 19.
Who expanded cell theory by suggesting that all cells arise from pre-existing cells?
Q 20.
Who coined the term 'protoplasm'?
Q 21.
Name the biggest cell in human body.
Q 22.
Give examples of cells which are muti-nucleate (i.e. having many nuclei).
Q 23.
Which organ of the plant body helps in osmoregulation?
Q 24.
What are the function of nucleus?
Q 25.
Who proposed the cell theory?
Q 26.
Give an example of anucleate cell i.e. cell without nucleus.
Q 27.
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 28.
Which cell organelle is called 'transport system'?
Q 29.
Identify cell organelle and write down its name:
Called 'suicide bags' of a cell.
Q 30.
Name the smallest cell in human body.
Q 31.
What are different types transport of components across cell membrane?
Q 32.
What is the thickness of cell membrane?
Q 33.
Identify cell organelle and write down its name:
Contains green colour pigment, traps light energy. Present in some plant cells.
Q 34.
Identify cell organelle and write down its name:
Present in some animal cells, help in locomotion.
Q 35.
Give an example of cells containing two nuclei (Binucleate).
Q 37.
What is plasmolysis?
Q 38.
When chromosomes are visible in the nucleus?
Q 39.
What are the conditions for osmosis?
Q 40.
Will the temperature have any effect on the process of the osmosis?
Q 41.
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 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.
Identify cell organelle and write down its name:
Powehouse of cell
Q 44.
Name the cell in human body which cannot reproduce.
Q 45.
Who proposed fluid-mosaic model of cell or plasma membrane?
Q 46.
Who is known as 'Father of Microscopy'?
Q 47.
Who discovered nucleus in the cell?
Q 48.
Name the cell type that have internal membranes which compartmentalize their functions.
Q 49.
Identify cell organelle and write down its name:
Jelly like substance containing particles and other organelles. What is it?
Q 50.
Identify cell organelle and write down its name:
Appear brown dots either present freely in cell or bound to a membrane and make proteins.
