Cell Cycle and Cell Division

Given below are two statements: In the light of the above statements, choose the most appropriate answer from the options given below:

1. Both Statement I and Statement II are incorrect.
2. Statement I is correct but Statement II is incorrect.
3. Statement I is incorrect but Statement II is correct.
4. Both Statement I and Statement II are correct.

Which one of the following never occurs during mitotic cell division?

1. Spindle fibres attach to kinetochores of chromosomes
2. Movement of centrioles towards opposite poles
3. Pairing of homologous chromosomes
4. Coiling and condensation of the chromatids

The appearance of recombination nodules on homologous chromosomes during meiosis characterizes:

1. Synaptonemal complex
2. Bivalent
3. Sites at which crossing over occurs
4. Terminalization

Regarding Meiosis, which of the statements is incorrect?

1. There are two stages in Meiosis, Meiosis-I and II
2. DNA replication occurs in S phase of Meiosis-II
3. Pairing of homologous chromosomes and recombination occurs in Meiosis-I
4. Four haploid cells are formed at the end of Meiosis-II

Select the incorrect statement with reference to mitosis :

1. All the chromosomes lie at the equator at metaphase
2. Spindle fibres attach to centromere of chromosomes
3. Chromosomes decondense at telophase
4. Splitting of centromere occurs at anaphase

Which stage of meiosis can last for months or years in the oocytes of some vertebrates?

1. Diakinesis
2. Leptotene
3. Pachytene
4. Diplotene

In meiosis, crossing over and exchange of genetic material between homologous chromosomes are catalyzed by the enzyme

1. Polymerase
2. Phosphorylase
3. Recombinase
4. Transferase

Identify the correct sequence of events during Prophase I of meiosis: Choose the correct answer from the options given below:

1. A, C, D, E, B
2. A, B, C, D, E
3. B, C, D, E, A
4. B, A, C, E, D

Bivalent or Tetrad formation is a characteristic feature observed during

1. Chiasmata in zygotene stage
2. Synaptonemal complex in zygotene stage
3. Chiasmata in Diplotene stage
4. Synaptonemal complex in Pachytene stage

With respect to metaphase, which of the following statements is incorrect?

1. Chromosomes lie at the equator of the cell
2. Complete disintegration of nuclear envelope takes place
3. Chromosomes are highly condensed
4. Metaphase chromosomes are made up of four sister chromatids held together by centromere