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.
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 associates 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
Identify the correct statement regarding meiosis amongst the following:
I. Meiosis involves two sequential cycles of nuclear and cell divisions but only a single cycle of DNA replication.
II. Meiosis II is initiated after the parental chromosomes have replicated to produce identical sister chromatids at the S phase
III. Meiosis involves pairing of bivalents and recombinations between them.
1. I only
2. I and II only
3. I and III only
4. I, II and III
The enzymes that catalyse removal of groups from substrates by mechanisms other than hydrolysis leaving double bonds are called as:
1. Oxidoreductases
2. Hydrolases
3. Ligases
4. Lyases
Consider the following two statements:
I. The growth of multi-cellular organisms is due to mitosis.
II. Mitosis results in the production of diploid daughter cells with identical genetic complement usually.
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
Consider the following two statements:
III. Plant cells undergo cytokinesis in a different manner than the animal cells
IV. 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
Consider the following enzymes:
I. Catalase
II. Peroxidase
III. Carboxypeptidase
Which of these enzymes require haem as a cofactor for their activity?
1. I only
2. I and II only
3. II and III only
4. I, II and III