Chapter 15

Question 1

The chromosomal theory of inheritance

Answer 1

-menadelian genes have specific loci on chromosomes
-chromosomes undergo segregation and independent assortment

Question 2

Non disjunction

Answer 2

Members of a pair of chromosomes do not move apart during meiosis 1 or sister chromatids fail to separate during meiosis 2

Question 3

Genomic imprinting

Answer 3

Variation in the phenotype depending on whether the allele was inherited from the male or female parent

Question 4

SRY

Answer 4

A gene on the Y chromosome required for the development of testes and it codes for a protein that regulates other genes

Question 5

Sturtevant’s prediction

Answer 5

The farther apart two genes are, the higher the probability that a crossover will occur between them and therefore the higher the recombination frequency

Question 6

Name and describe the alteration of chromosome structure

Answer 6

1. Deletion-a chromosomal fragment is lost
   2.Duplication- a “deleted” fragment reattaches to a sister chromatid/a non sister chromatid
   3.Inversion- the fragment reattaches to its original chromosome but in the reverse orientation
2. Translocation- the fragment joins a non homologous chromosome