Q24
2 marksVery Short AnswerSection B

Some unicellular organisms such as Plasmodium and Leishmania differ in the manner in which they reproduce. Name and explain the reproductive process taking place in them.

How do Organisms Reproduce?
Fission in Unicellular Organisms
Official Answer

The reproductive processes in Leishmania and Plasmodium differ as follows:


  1. Leishmania (Binary Fission):
  • Leishmania reproduces by binary fission.
  • It has a whip-like structure (flagellum) at one end of the cell.
  • Because of this organized body structure, cell division occurs in a definite orientation (longitudinal plane) in relation to the whip-like structure, splitting the parent cell into two equal daughter cells.

  1. Plasmodium (Multiple Fission):
  • Plasmodium reproduces by multiple fission.
  • The single-celled malarial parasite divides into many daughter cells simultaneously within a protective wall, which then ruptures to release them.
Leishmaniabinary fissiondefinite orientationwhip-like structurePlasmodiummultiple fissionmany daughter cells simultaneously

Marking Scheme

  • 11 Mark: Naming and explaining binary fission in Leishmania with reference to its definite orientation.
  • 21 Mark: Naming and explaining multiple fission in Plasmodium where it divides into many daughter cells simultaneously.

Hint

Recall how many daughter cells are produced at a time in each organism and whether there is any specific body orientation involved.

Quick Oral Answer

Leishmania reproduces by binary fission in a definite orientation due to its whip-like flagellum, whereas Plasmodium reproduces by multiple fission, dividing into many daughter cells simultaneously.

Analysis & Explanation

Unicellular organisms exhibit different patterns of fission based on their cellular organization. Leishmania has a whip-like structure at one end, which constrains the plane of division, leading to binary fission in a definite orientation. On the other hand, Plasmodium undergoes multiple fission where the nucleus divides repeatedly to produce many daughter cells simultaneously, allowing rapid multiplication inside the host.

Common Mistakes

  1. 1Students often write 'binary fission' for both without specifying the 'definite orientation' for Leishmania, or they confuse multiple fission with fragmentation.

Interesting Facts

Plasmodium uses multiple fission as an evolutionary strategy to rapidly multiply inside the host's red blood cells and liver cells, causing the symptoms of malaria in a very short time.

Spotted a mistake or something unclear?

Tell us — we fix reported answers fast.

Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2024?

This question carries 2 marks in the CBSE Class 10 Science 2024 examination.

Which chapter does this question come from in Science?

This question is from the chapter "How do Organisms Reproduce?" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Fission in Unicellular Organisms" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2024 paper?

This is a Very Short Answer question from Section B in the CBSE Class 10 Science 2024 paper.