Bio 130 – Quiz April 11

1. Bio 130 – Quiz April 11

2. Q. 1 - Chromosomal rearrangements can occur after chromosomes break. Which of the following statements are most accurate with respect to alterations in chromosome structure? • Chromosomal rearrangements are more likely to occur in mammals than in other vertebrates. • Translocations and inversions are not deleterious because no genes are lost in the organism. • Chromosomal rearrangements are more likely to occur during mitosis than during meiosis. • An individual that is homozygous for a deletion of a certain gene is likely to be more damaged than is an individual that is homozygous for a duplication of that same gene because loss of a function is more likely to be lethal.

3. Q. 2 - Imagine that a deleterious allele occurs on the W chromosome of a chicken (2n = 78). Where would it be most likely to appear first in a genetics experiment? (Remember birds are ZW female, ZZ male) • in a male because there is no possibility of the presence of a normal, dominant allele • in a male because it is haploid • in a female because there is no possibility of this deleterious allele showing up in a male • in a female because the Z chromosome will form a Barr Body • none of the above

4. Q. 3 – Determine the sequence of genes along a chromosome based on the following recombination frequencies: A-B, 8 map units; A-C, 15 map units; A-D, 25 map units; B-C, 20 map units; B-D, 33 map units. • In order A – B – C – D • In order B – A – C – D • In order B – C – A – D • In order B – C – D – A • In order D – B – A - C