NEET 2016
- Exam
- NEET
- Year
- 2016
- Subject
- Botany
- Chapter
- Cell Cycle and Cell Division
NEET 2016 · Botany · Cell Cycle and Cell Division
Match the stages of meiosis of Column-I to their characteristic...
Match the stages of meiosis of Column-I to their characteristic features in Column-II and select the correct option using the codes given below:
| Column-I | Column–II | ||
| a. | Pachytene | (i) | The pairing of homologous chromosomes |
| b. | Metaphase I | (ii) | Terminalization of chiasmata |
| c. | Diakinesis | (iii) | Crossing-over takes place |
| d. | Zygotene | (iv) | Chromosomes align at the equatorial plate |
Options
- A(
)a b c d (iii) (iv) (ii) (i) - B(
)a b c d (i) (iv) (ii) (iii) - C(
)a b c d (ii) (iv) (iii) (i) - D(
)a b c d (iv) (iii) (ii) (i)
Correct answer
A. (
| a | b | c | d |
| (iii) | (iv) | (ii) | (i) |
Step-by-step solution
Zygotene:
- Chromosomes start pairing together. This process is called synapsis. The paired chromosomes are called homologous chromosomes.
- The formation of synapsis is accompanied by the formation of the synaptonemal complex.
- The synaptonemal complex by a pair of homologous chromosomes is called a bivalent or a tetrad.
Pachytene:
- Bivalent chromosomes clearly appear as tetrads, at this stage.
- Recombination nodules appear. These nodules are the sites at which crossing overtakes place between non-sister chromatids of the homologous chromosomes.
- The exchange of genetic materials between two homologous chromosomes takes place during crossing over. This leads to the recombination of genetic materials on the two chromosomes.
Diakinesis:
- Chiasmata is terminated at this stage.
- Meiotic spindles are formed to prepare the homologous chromosomes for separation.
- The nucleolus disappears and the nuclear envelope breaks down by the end of diakinesis.
Metaphase I:
- The bivalent chromosomes are aligned on the equatorial plate.
- Spindle fibres from opposite poles attach to the pair of homologous chromosomes.