10. Cell and Cell Organelles
1. Who am I ?
a. I
am ATP producing factory.
Ans: a.
Mitochondria
b. I am
single layered, but maintain cellular osmotic pressure.
Ans: Cell wall
c. I support the cell, but I am not cell wall.
I have a body resembling net.
Ans: Cell
membrane
d. I am
chemical factory of the cell.
Ans: Mitochondria
e.
Leaves are green because of me.
Ans: Chlorophyll
2. What would have happened ?
If.......
a. RBCs had mitochondria.
Ans: Mitochondria continuously carry out oxidation
and form energy inside the cell. They produce energy-rich compound, ATP. In
this process, they utilize carbohydrates, fats and proteins present in the
cell. If RBCs has mitochondria, they would have used oxygen for this purpose
than carrying it to all the cells of the body. The cells would not have
obtained oxygen.
b.There
had been no difference between mitochondria and plastids.
Ans: Mitochondria carry out oxidation of
carbohydrates, fats, etc. with the help of enzymes. Plastids are synthesising
carbohydrates with the help of solar energy and chlorophyll. Both the cell
organelles have their own sets of different enzymes as per their role. If there
would have been no difference between mitochondria and plastids, the specific
functions would not have been taken place.
c.
Genes had been absent on the chromosomes.
Ans: Genes are functional segments on the
chromosomes which are responsible for transmitting the hereditary information.
d.
Plasma membrane had not been selectively permeable.
Ans: Selectively permeable membrane allows some
substances to enter the cell, while prevents other unwanted or harmful
substances. If plasma membrane would not have been selectively permeable, there
would be no control over entry and exit of any substances. The process of
osmosis would also be erroneous in such case.
e. Plants lacked anthocyanin.
Ans: If
plants lacked anthocyanin, no part of the plant would display purple or blue
colour. Anthocyanin attracts the insects for pollination and seed dispersal.
These processes will be affected due to lack of anthocyanin. These pigments are
also said to be protective in nature for the plant. This protection will not be
given to the plant in absence of anthocyanin.
3. Who is odd man among us? Give reason.
a.
Nucleolus, mitochondria, plastids, endoplasmic reticulum
Ans: Plastids are
the odd one out because they are organelles which are found only in plant
cells. Rest all the organelles are found in both plants and animals.
b. DNA,
Ribosomes, Chlorophyll
Ans: Chlorophyll
is the odd one out beacuse it is a type of pigment which is found in plants
only. DNA and ribosomes are found in both plants and animals.
4. Give functions.
a.
Plasma membrane
Ans: Functions of the plasma
membrane:
- It gives shape
and support to the cell.
- It acts as a
mechanical barrier to protect the internal contents of the cell.
- It separates
the contents of the cell from its surrounding medium.
- It performs
physical activities such as diffusion and osmosis.
b.
Cytoplasm
- It is the
medium for all cellular chemical reactions.
- It is a medium
in which the organelles remain suspended.
- It helps in
the movement of the different cellular elements.
c. Lysosome
Ans:
1.
Immune system - It destroys viruses and bacteria that attack the cell.
2.
Demolition squads - It is destroys worn out cellular organelles and
organic debris. (Autolysis)
3.
Suicide Bags - When a cell becomes old or is damaged, lysosomes burst
and enzymes digest their own cells.
4. During starvation, lysosomes digest stored
proteins, fats.
d. Vacuole
Ans: 1. To maintain the osmotic pressure of
the cell.
2. To
store metabolic byproducts and end products. (Glycogen, proteins, water etc).
3. In animal cell, they store waste products
and food, while in amoeba it stores food before digestion.
4. In
plant cell, vacuoles are full of cell sap and provide turgidity, rigidity to
them.
e. Nucleus
Ans: 1.
It controlls all metabolic activities of the cell and also the cell
division.
2. It
is involved in the transmission of hereditary characters from parents to
offsprings.
5. Who gives me the colour? (Select
the correct option.
a. Red tomato 1. Chlorophyll
b. Green leaf 2. Carotene
c. Carrot 3.
Anthocyanin
d.
Violet 4. Lycopene
|
a. Red
tomato |
4.
Lycopene |
|
b. Green
leaf |
1.
Chlorophyll |
|
c. Carrot |
2.
Carotene |
|
d. Violet |
3.
Anthocyanin |