Question 2 - Case Based Questions (MCQ) - Chapter 8 Class 10 - How do Organisms Reproduce?

Study the process depicted in the picture given below and answer any four question from (a) to (e):

(a) Which of these organisms divides by the above process?

(i) Amoeba

(ii) Spirogyra

(iii) Leishmania

(iv) Yeast

(b) How the above process is different from multiple fission.

(c) Which of the following statement is correct about the above type of reproduction?

(i) It involves two individuals.

(ii) It involves a mature parent cell.

(iii) It involves union of two types of gametes.

(iv) All of these

(d) Differentiate between fission in above organism and Leishmania.

(e) Which of these are the characteristics of vegetative reproduction?

I. Involves two individuals

II. Daughter cells are genetically identical to the parent.

III. The cell division is only mitotic.

(i) I and II only

(ii) I, and III only

(iii) II and III only

(iv) All of these

Answer:

(a)

The process depicted in the above image is binary fission.

Checking the options:

• (i) Amoeba - Reproduces through binary fission.
• (ii) Spirogyra - Reproduces through fragmentation. 
• (iii) Leishmania - Reproduces through binary fission.
• (iv) Yeast - Reproduces through budding.

Even though Amoeba and Leishmania reproduce through binary fission, Leishmania undergoes binary fission along a definite plane with respect to its flagellum whereas Amoeba undergoes binary fission along any plane.

In the process depicted above, binary fission does not occur along a definite plane. 

So, the correct answer is (i) Amoeba.

(b)

In binary fission, the parent organism splits into 2 daughter cells whereas in multiple fission, the parent organism splits into many daughter cells simultaneously.

(c)

Binary fission is an asexual mode of reproduction in which a single mature parent cell splits into 2 daughter cells.

Checking the options

• (i) It involves two individuals - This is incorrect.
• (ii) It involves a mature parent cell - This is correct.
• (iii) It involves union of two types of gametes - This is incorrect.
• (iv) All of these

 So, the correct answer is (ii)It involves a mature parent cell.

(d)

(e) 

Vegetative reproduction is an asexual method of reproduction in which mitotic cell division leads to the formation of new plants obtained from the parts of old plants like stem, roots and leaves.

Checking the options

• I. Involves two individuals   - This is incorrect.
• II. Daughter cells are genetically identical to the parent - This is correct.
• III. The cell division is only mitotic - This is correct.

So, the correct answer is (iii) II and III only.