Consider the following statements regarding meiosis:
I: | At metaphase I, the microtubules from the opposite poles of the spindle attach to the pair of homologous chromosomes. |
II: | At anaphase I, the homologous chromosomes separate, while sister chromatids remain associated with each other. |
Of the two statements:
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
During meiosis, the bivalent chromosomes clearly appear as tetrads first at:
1. | Zygotene of Prophase I | 2. | Pachytene of Prophase I |
3. | Metaphase I | 4. | Anaphase I |
Consider the following key events:
I: | Chromosomes cluster at opposite spindle poles and their identity is lost as discrete elements. |
II: | Nucleolus, Golgi complex and ER reform. |
The stage of mitosis characterized by these key events is:
1. | Prophase | 2. | Metaphase |
3. | Anaphase | 4. | Telophase |
During diakinesis of prophase I:
I. Terminalisation of chiasmata takes place.
II. Meiotic spindle is assembled.
III. Nucleolus disappears and the nuclear membrane breaks down.
The correct statements are:
1. | I, II and III | 2. | I and II only |
3. | I and III only | 4. | II and III only |
Consider the following two statements:
I: | Plant cells undergo cytokinesis in a different manner than the animal cells. |
II: | Plant cells are enclosed by a relatively inextensible cell wall. |
Of the two statements:
1. Both I and II are correct and II explains I
2. Both I and II are correct but II does not explain I
3. I is correct but II is incorrect
4. I is incorrect but II is correct
What stage of the cell division is shown in the following diagram of a cell undergoing cell division?
1. | Prophase I | 2. | Prophase II |
3. | Telophase I | 4. | Telophase II |
At which stage of the cell cycle is the cell shown in the given diagram?
1. G1 | 2. S |
3. G2 | 4. M |
The most important significance of meiosis is that:
1. | It increases variations in the gene pool of the species that helps in evolution of that species. |
2. | It causes growth in the multicellular organisms. |
3. | It conserves specific number of chromosomes in each species across generations. |
4. | It is vital for repair and regeneration functions in the living organisms. |
With respect to meiosis, when does DNA replication occur?
1. | Before meiosis I only | 2. | After meiosis I only |
3. | Before and after meiosis I | 4. | After meiosis II |
Organisms prefer sexual mode of reproduction in adverse conditions because:
1. | It leads to a rapid proliferation of numbers |
2. | It requires two individuals that can support the progeny |
3. | It is less energy consuming than the asexual mode of reproduction |
4. | It provides protection and increases variations that may help progeny to survive |