Genetics Answers

A gene of curly hair structure dominates over a gene of straight hair structure and hemophilia is X-linked recessive disease in a human. A healthy woman with curly hair got married to a healthy man with straight hair. They had two children: a hemophilic son with curly hair and a healthy daughter with straight hair. Determine the genotypes of the parents and their children. Determine the probability of birth of a healthy son with straight hair structure

A brown-eyed girl with normal sight got married to a blue-eyed man with normal sight. The father of the girl was blue-eyed and color-blind. What is F1? It is known that gene of brown color of eye dominates over the gene of blue eye color. The gene of color blindness is recessive and X-linked.

The gene of daltonism is recessive X-linked. Woman with normal sight, whose father had daltonism, got married to sick man. Determine the phenotypes and genotypes of children in this family, and the probability of birth of healthy children.

UN2005/UN2401 ’18 Exam #3 Nov 15, 2018
1. You have a double stranded (ds) DNA molecule. You want to use PCR to make multiple copies of a section of it. Suppose you start with one molecule of ds DNA and do 5 cycles of PCR.
A-1. How many different primers will you need? (1) (2) (3) (4) (5) (>5).
A-2. How many molecules of each primer will you need? (1) (2) (3) (4) (5) (>5).
A-3. Your primers are most likely to be (ss RNA) (ssDNA) (dsRNA) (dsRNA) (ss, but equally likely to be RNA or DNA). No explanation required for A-1 to A-3. Note: ds = double stranded; ss = single stranded.
A-4. Consider two different primers. (There may or may not be more, but stick to 2.) The two primers are probably (complementary) (unrelated in sequence) (the same sequence but one is ‘backwards’).

In Drosophila (fruit flies), cut wings are controlled by a recessive X – linked allele
(ct), and fuzzy body is controlled by a recessive autosomal allele (fy). When a
fuzzy female is mated with a cut male, all the members of the F1 generation are
wildtype. What are the genotypic and phenotypic ratios of the F2 by sex?

Hybridization of a homozygous dominant and homozygous recessive plant was conducted. What is the probability that the F2 will have the phenotype big oval shaped yellow leaves, white flowers, and pink fruits?

You found morning glory plants in a field by your house with flowers that can have two different colors: dark purple (CPCP) or white (CWCW). You pollinate purple flowers with pollen from white flowers. When you grow the F1 progeny you get plants with only light purple flowers! (1) Name the inheritance pattern that likely led to these phenotypes. If you self-pollinate the F1 progeny, use a Punnett square to predict (2) the genotypic ratio and (3) phenotypic ratio for flower color in the F2 progeny.