UPSC Prelims 2020 Question:

Which of the following statements are correct regarding the general difference between plant and animal cells?

1. Plant cells have cellulose cell walls whilst animal cells do not.
2. Plant cells do not have plasma membrane unlike animal cells which do.
3. Mature plant cell has one large vacuole whilst an animal cell has many small vacuoles.
   
   

Select the correct answer using the code given below:

Explanation:

• Plant cells have a rigid outer covering called the cell wall. It lies outside the plasma membrane. The plant cell wall is mainly composed of cellulose. Cellulose is a complex substance and provides structural strength to plants. Animal cells lack cell wall. Plant cells can withstand much greater changes in the surrounding medium than animal cells because of their cell walls. So, statement 1 is correct.
  
  
• Plasma membrane, also called cell membrane. It is the outermost covering of the cell that separates the contents of the cell from its external environment. It is flexible and is made up of organic molecules called lipids and proteins. It allows or permits the entry and exit of some materials in and out of the cell. It also prevents movement of some other materials. It is found in all cells (plants as well as animals). So, statement 2 is not correct.
  
  
• Vacuoles are storage sacs for solid or liquid contents. Vacuoles are of small size in animal cells while plant cells have very large vacuoles. The central vacuole of some plant cells may occupy up to 90 percent of the cell volume. In plant cells vacuoles are full of cell sap and provide turgidity and rigidity to the cell. Many substances of importance in the life of the plant cell are stored in vacuoles. So, statement 3 is correct.
  
  

Therefore, option (3) is the correct answer.

Subject: Science & Technology | Biology