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
Cells at the end of prophase of mitosis, when viewed under the microscope, do not show:
I. Golgi complexes
II. Endoplasmic reticulum
III. Nucleolus
IV. Nuclear envelope
1. Only I and II are correct
2. Only III and IV are correct
3. Only II, III and IV are correct
4. I, II, III and IV are correct
The stage of mitosis at which morphology of chromosomes is most easily studied is the:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
Consider the following events:
I. Centromere split and chromatids separate.
II. Chromatids move to opposite poles
The stage of mitosis characterized by these two events is:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
The property of the water molecule that is most important for the maintenance of homeostasis in living organisms is:
1. High latent heat of vaporization
2. High latent heat of fusion
3. High specific heat
4. Liquid form more dense than solid form
Chitin, a complex polysachharide is found in:
1. Plant cell wall
2. The exoskeleton of arthropods and cell walls of most fungi
3. Bacterial cell wall
4. Cartilage and other connective tisuue