A student was given two permanent slides, one of binary fission in amoeba and other of budding in yeast. He was asked to identify any one difference in the nucleus of the two. One such difference, he identified correctly was:
A student was given two permanent slides, one of binary fission in amoeba and other of budding in yeast. He was asked to identify any one difference in the nucleus of the two. One such difference, he identified correctly was:
Options
Official answer
The correct option is 2: Presence of two nuclei in centrally constricted amoeba, one in yeast cell and one in its bud.
Marking scheme
- 1.1 mark
Hint
Consider the stage of division. A centrally constricted Amoeba is in the middle of cytokinesis, meaning its nucleus has already split into two.
Quick oral answer
In a centrally constricted Amoeba undergoing binary fission, we observe two nuclei because nuclear division (karyokinesis) is completed before the cell splits. In budding yeast, both the parent cell and the attached bud contain one nucleus each.
Common mistakes
- 1.Selecting option 4, assuming that since they are single-celled, they always have only one nucleus, forgetting that during division the nuclei must duplicate and separate.
Analysis and explanation
Let us analyze the nuclear division in both processes:
- Binary Fission in Amoeba: During binary fission, karyokinesis (division of the nucleus) occurs first. When the cell body is centrally constricted (cytokinesis stage), the nucleus has already divided into two distinct nuclei, one moving to each half of the constricting cell. Thus, a centrally constricted Amoeba contains two nuclei.
- Budding in Yeast: In yeast, the parent cell has one nucleus. During budding, the nucleus divides, and one daughter nucleus migrates into the developing bud. Thus, the parent yeast cell has one nucleus and its attached bud has one nucleus.
Therefore, Option 2 is the only correct statement.
Interesting facts
In Amoeba, the splitting of the cell during binary fission can take place in any plane, unlike in Leishmania where it occurs in a definite orientation relative to its whip-like structure.
Question details
Q37 of 36 questions
- Board
- CBSE
- Class
- Class 10
- Subject
- Science
- Year
- 2011
- Section
- Section B
- Marks
- 1
- Type
- MCQ
- Chapter
- How do Organisms Reproduce?
- Topic
- Asexual Reproduction - Binary Fission and Budding
- Bloom's level
- Analyze
- Syllabus topic
- Asexual reproduction: fission, fragmentation, regeneration, budding, vegetative propagation, spore formation
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Frequently asked questions
How many marks does this question carry in CBSE Class 10 Science 2011?
This question carries 1 mark in the CBSE Class 10 Science 2011 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 "Asexual Reproduction - Binary Fission and Budding" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2011 paper?
This is a MCQ question from Section B in the CBSE Class 10 Science 2011 paper.