1. Insertion and deletion mutations can be caused by which of the following? a.

Question

1. Insertion and deletion mutations can be caused by which of the following?

a. strand slippage during replication

b. unequal crossing over between homologous chromosomes

c. depurinatin

d. A and B

e. A, B and C

2.  the greater degree of phenotypic variation observed in human females compared to males is explained by

a. genomic imprininting

b. mosaicism

c. chromosomal nondisjunction

d. genetic epistasis

e. incomplete dominance

3. Most cases of Down's syndrome are ......and result from ......but a few rare cases are ....and result from .....

a. hereditary, a translocation between chromosome 21 and an autosome-usually chromosome 14 or 15 , non hereditary, having 3 copies of chromosome 21

b. hereditary, having 3 copies of chromosome 21 nonhereditary, hereditary, a trasnlocation between chromosome 21 and an autosome usually chromosome 14 or 15.

c. nonhereditary, a translocation between chromosome 21 and an autosome-usually chromosome 14-15, hereditary, having 3 copies of chromosome 21

d. nonhereditary, having 3 copies of chromosome 21, hereditary, a translocation between chromosome 21 and an autosome usually chromosome 14 or 15.

4.

Genotype.                    Number

S1S1.                                                  3

S1S2.                                                   44

S2S2.                                            103

Based upon the phosphoglucose isomerase genotypes determined in a water flea population and tabulated above, what is the frequency of the S1 allele in this population?

0.1

0.17

c. 0.3

0.6

5. If 4 distinct loci A,B,C,and D contribute equally and incrementally to the height of a plant and each locus has 2 distinct alleles ( one completely dominant over the other), how many different phenotypes exists for the trait?

a.4

b.8

c.9

d.12

e.13

6. The number of chromosomes in each daughter cell at the end of Mitosis is ................. the number of chromosomes per cell at the beginning of Mitosis and the number of chromosomes In a cell at the beginning of Meiosis is ............... the number of chromosomes in each daughter cell at the end of Meiosis.

a.equal to; half

b. half;twice

c.equal;twice

d. twice; half

e.half; equal to

7. Assume that long ear lobes manifests in a population as an autosomal dominant trait that exhibits 50% penetrance. A person who is heterozygous for long ear lobes mates with person who has typical ear lobes. What is the probability that their first child will have long ear lobes?

a. 50%

b.30%

c.15%

d.25%

e.35%

Explanation / Answer

1. e. A, B and C

A permanent change in the sequence of nucleotides of the genome is called mutation, which results in altered or absence of corresponding protein synthesis. Mutation may occur either in DNA or RNA, and can be inherited. Based on the way of change in base sequence in the genome, they are classified into point mutations and chromosomal mutations.

Insertion or deletion of single base pairs in DNA results in frame shift mutations, in this; the reading frame shifts at the point of mutation and results in non-functional proteins. This may occur during depurination (deletion of purine nucleotides), unequal crossing over between homologous chromosomes or due to strand slippage during replication.

2.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.