Question

Consider your body cells. Which of the following cellular components will not be present in your cells? 

a Cytoplasm
b Mitochondria
c Plastids
d Ribosomes​

Answer 1

Explanation:

If we consider our body cells [animal cells]. The cellular component which will not be present is :

• Plastids

Let's know about these :

》Cytoplasm

1. They are present in both animal, plant cells.
2. All the parts together inside the plasma membrane excluding nucleus.
3. Contains a mixture of water and soluble organic and inorganic compounds and various organelles.
4. All metabolic activities occur in it.
5. Medium for initial steps of respiration, anaerobic respiration and production of pyruvic acid.

》Mitochondria

1. They are present in both animal, plant cells.
2. Have their own DNA.
3. Also contain their own ribosomes.
4. Synthesis of respiratory enzymes.
5. Release of energy from pyruvic acid and produced in cytoplasm in the form of ATP. Seat of cellular aerobic respiration and stores energy.

》Ribosomes

1. They are present in both animal, plant cells.
2. Their function is protein synthesis.
3. Small granules either scattered in the cytoplasm or attached to the outside of endoplasmic reticulum.
4. Single walled.
5. They are dense, spherical bodies, composed mainly of RNA.

》Plastids

1. They are present only in plant cells.
2. They are several kinds, most common ones are chloroplasts containing green pigment chlorophyll.
3. Double membraned, proteinaceous matrix, contain DNA.
4. Disc-like structures called thylakoids contain chlorophyll.

TYPES OF PLASTIDS :

• Chloroplasts : green in color, trap solar energy for photosynthesis, contain the pigment chlorophyll.
• Leucoplasts : colorless, store starch and have no pigment.
• Chromoplasts : variously colored, impart color to flowers and fruits, contain the pigments Xanthophyll, Carotene. They also indirectly help in pollination by attracting different pollinators which then help disperse seeds.

...ッ