Question

Which of the following is NOT a normal event in prophase I of meiosis? Group of answer choices

1. synapsis of homologous chromosomes

2. meiotic recombination

3. formation of a synaptonemal complex

4. condensation of chromosomes

5. none of the above (i.e. all the above ARE features of prophase I of meiosis.)

Answer 1

5. None of the above ( all the above are features of prophase I of meiosis.

In prophase I of Meiosis Have five phases based on chromosomal behaviour, i.e., Leptotene, Zygotene, Pachytene, Diplotene and Diakinesis.

In leptotene, condensation/compaction of chromosomes occur.

In zygotene, chromosomes start pairing, this association is known as synapsis. Chromosomes are know as homologous chromosomes. Hence, synapsis of homologous chromosomes occur (known as bivalent Or tetrad) which is accompanied by the formation of complex structure called synaptonemal complex.

In pachytene, the four chromatids of each bivalent chromosomes becomes distinct and clearly appears as tetrads. This stage is characterised by the appearance of recombination nodules, the sites at which crossing over occurs between non-sister chromatids of the homologous chromosomes.

The beginning of diplotene is recognised by the dissolution of the synaptonemal complex and at end it has x shaped structures called chiasmata.

Diakinesis is marked by terminalisation of chiasmata. Complete conpaction takes place.

Since, all events given in question took place therfore the option 5 is correct.