Bio 130 – Quiz April 11

Q. 1 - Chromosomal rearrangements can occur after chromosomes break. Which of the following statements are most accurate with respect to alterations in chromosome structure? A.Chromosomal rearrangements are more likely to occur in mammals than in other vertebrates. B.Translocations and inversions are not deleterious because no genes are lost in the organism. C.Chromosomal rearrangements are more likely to occur during mitosis than during meiosis. D.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.

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) A.in a male because there is no possibility of the presence of a normal, dominant allele B.in a male because it is haploid C.in a female because there is no possibility of this deleterious allele showing up in a male D.in a female because the Z chromosome will form a Barr Body E.none of the above

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. A.In order A – B – C – D B.In order B – A – C – D C.In order B – C – A – D D.In order B – C – D – A E.In order D – B – A - C