Question

After genotyping alleles on chromosome 18 the following genotypes were determined: Father-
5/8 Mother 6/3 Child 3/3/5 (each number represents a different allele for the same gene on a
different chromosome). In which parent and at what stage of meiosis did nondisjunction most
likely occur. Explain your reasoning.

Answer 1

Non-disjunction occurred during meiosis II in the maternal germinal line. Non-disjunction may occur during meiosis I or meiosis II.

What is non-disjunction?

Non-disjunction refers to the phenomena where homo-logous chromosomes or sister chromatids are not separated properly during cell division.

Non-disjunction during meiosis II is due to the failure of the sister chromatids to separate during Anaphase II.

In this case, the genotype of the father is 5/8, thereby transmitting alleles number 5 and 8.

Moreover, the genotype of the mother is 6/3, thereby she is able to transmit alleles number 6 and 3.

Learn more about non-disjunction here:

https://brainly.com/question/1274629