NEET 2014
- Exam
- NEET
- Year
- 2014
- Subject
- Botany
- Chapter
- Cell Cycle and Cell Division
NEET 2014 · Botany · Cell Cycle and Cell Division
The enzyme recombinase is required at which stage of meiosis:
The enzyme recombinase is required at which stage of meiosis:
Options
- APachytene
- BZygotene
- CDiplotene
- DDiakinesis
Correct answer
A. Pachytene
Step-by-step solution
The characters of Pachytene/Pachynema are as follows-
- Crossing over i.e. exchange of segments between non-sister chromatids of homologous chromosome occurs at this stage.
- Chromatids of pachytene chromosome are attached with centromere.
- A tetrad consists of two sets of homologous chromosomes each with two chromatids. Each tetrad has four kinetochore (two sister and two homologous).
- A number of electron dense bodies about 100 nm in diameter are seen at irregular intervals within the centre of the synaptonemal complex, known as recombination nodules.
- Enzyme recombinase is responsible for causing crossing over.
- Crossing over leads to recombination of genes and hence, variations.