MCQ Questions

Which of the following statements is not related to the endoplasmic reticulum?

1. It behaves as a transport channel for proteins between the nucleus and cytoplasm.
2. It transports materials between various regions in cytoplasm.
3. It can be the site of energy generation.
4. It can be the site of some biochemical activities of the cell.

Answer:

The endoplasmic reticulum is a network of tubes and sheets .

• It looks like long tubules or round or oblong bags .
• This organelle makes and transports proteins in the cell.
• There are two kinds of Endoplasmic Reticulum:

• • Rough endoplasmic reticulum(RER) : It is responsible for production of proteins .
  • Smooth endoplasmic reticulum(SER) : It is responsible for production of fats and steroids . 

On the other hand, Mitochondria is the site of energy generation .

So, the correct answer is (c).

You must have observed that a fruit when unripe is green but it becomes beautifully coloured when ripe. According to you, what is the reason behind this colour change?

1. Chloroplasts change to chromoplasts
2. Chromoplasts change to chromosomes
3. Chloroplasts change to chromosomes
4. Chromoplasts change to chloroplasts

Answer:

• Action of enzymes in the fruit causes ripening . 
• These enzymes break down chloroplasts containing chlorophyll  into chromoplasts . 
• Chromoplasts are also pigment-containing plastids which lend the fruit its colour.

Anjali wanted to eat rice and kidney bean (rajmah). She requested her mother to cook the same the next day. At night her mother took a cup of kidney beans and put them in a container with some water and then kept the container covered overnight. Next day it was observed that the kidney beans got swollen and were ready to be cooked. What is this phenomenon due to which kidney beans get swollen is known as?

1. Osmosis                             
2. Diffusion
3. Endosmosis                     
4. Exosmosis

Choose the correct option among the following:

         (a) Only (iii)

         (b) Both (i) and (iii)

         (c) Both (i) and (iv)

         (d) Only (i)

Answer: 

Osmosis is a process in which water moves from a region of high water concentration to a region of low water concentration through a semipermeable membrane.

• Endosmosis is a type of osmosis where the water moves into the cell due to lower concentration of water inside it.
• Exosmosis is a type of osmosis where the water moves out of the cell due to lower concentration of water outside it.
• Diffusion is a process where a gas moves from a region of higher concentration to lower concentration. 

Therefore , the answer is (b) Both (i) and (iii)

Which among the following is not a function of the vacuole?

1. They help to store the toxic metabolic by-products of the plant cell.
2. They provide turgidity and rigidity to the plant cell.
3. They help to maintain the osmotic pressure in the cell.
4. They help the plant in its growth by the process of cell division.

Answer:

• Vacuoles are nothing but storage bags for the cell .
• Vacuoles can store oils, fats, waste, food, cell sap etc.
• They also help in maintaining osmotic pressure in plant cells, as well as provide rigidity and turgidity .
• However, they play no role in the process of cell division .

Therefore, the correct answer is (d).