Question

When a crossover occurs within the inversion loop of a pericentric inversion, each recombinant chromatid will have

Check All That Apply

• a dicentric bridge.

• a duplication of some genes in the inverted region..

• a deletion of some genes in the inverted region..

• one copy of each gene, with some genes in a different order than normal.al.

• one copy of each gene in the normal order.

Answer 1

This question based on concept of lnversion in chromosome

When a segment of chromosome break and reunite at same locus but in reverse orientation(180o) its called Inversion

2 Types

1) Paracentric = when centromere is not involved in inverted segment

2) Pericentric = when centromere is involved in inverted segment

Question is asking When a crossover occurs within the inversion loop of a pericentric inversion, each recombinant chromatid will have

As you can see above when cross over take place within inversion loop

In Non recombinant strand where no crossing over occur 1/2 have genes in Normal order and 1/2 have genes in inverted order

In recombinant strand formed after crossing over occur

deletion of some gene occur in normal order strand

duplication of some gene occur in inverted region

Now coming to the option one by one

Option 1 is false because dicentric bridge forms in Paracentric Inversion.In pericentric Inversion chromosome are Monocentric

Option 2 It is correct as we have seen above Duplication of some gene occur in inverted region

Option 3 It is false as duplication occur in inverted region not deletion

Option4&5 One copy of each gene, with some genes in a different order than normal &One copy of each gene in the normal order.

It is false because this occur when there is No crossing over within inversion loop and question asking about recombinant strand when there is crossing over within inversion loop

Hence correct answer is option 2

plz upvote my answer Thank you ?