From the following diagrams, select the correct ones showing stages of binary fission in Amoeba :
From the following diagrams, select the correct ones showing stages of binary fission in Amoeba :
Options
The correct diagrams showing the actual stages of binary fission in Amoeba are I, II, and III (Option A).
Marking Scheme
- 10.5 marks
- 20.5 marks
Hint
Look for the stages that represent a single parent cell, nuclear elongation, and equal cytoplasmic constriction. Exclude diagrams showing budding or multiple unequal divisions.
Quick Oral Answer
The three main stages of binary fission in Amoeba are: first, the parent cell stage; second, the karyokinesis stage where the nucleus elongates and divides; and third, the cytokinesis stage where the cytoplasm constricts to form two daughter cells.
Analysis & Explanation
Binary fission in Amoeba consists of specific, well-defined morphological changes:
Diagram I (Parent Cell): Shows a normal, single-celled Amoeba* with pseudopodia and a single nucleus.
- Diagram II (Nuclear Division): Shows the elongation of the nucleus, which is the initial phase of division.
- Diagram III (Cytoplasmic Division): Shows the constriction of the cell body and the separation of the two nuclei.
Distractor Analysis:
Diagram IV is incorrect because it depicts budding (unequal division where a small bud remains attached to the parent body), which is characteristic of yeast or Hydra, not Amoeba*.
Diagram V is incorrect because it shows multiple fission or irregular fragmentation, which does not represent the equal binary splitting of Amoeba* under normal conditions.
- Therefore, options containing IV or V (Options B, C, and D) are incorrect, making Option A (I, II, III) the only correct choice.
Common Mistakes
- 1Mistaking budding (IV) as a stage of binary fission in Amoeba, or failing to recognize that binary fission always results in two equal halves.
Interesting Facts
During binary fission, the parent cell completely loses its individual identity because its entire body is divided to form the two new daughter cells.
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Frequently Asked Questions
How many marks does this question carry in CBSE Class 10 Science 2012?
This question carries 1 mark in the CBSE Class 10 Science 2012 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" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2012 paper?
This is a MCQ question from Section B in the CBSE Class 10 Science 2012 paper.