Question

In: Biology

2. In butterflies, round eyes (re) and white body (wb) are encoded by two mutant alleles...

2. In butterflies, round eyes (re) and white body (wb) are encoded by two mutant alleles that are recessive to those that produce wild-type traits (re+ and wb+); these two genes are on the same chromosome. A butterfly homozygous for round eyes and white body is crossed with a butterfly homozygous for the wild-type traits. The F1 have normal eyes and normal body. The F1 are crossed with butterflies that have round eyes and white body in a testcross. The progeny of this testcross are:

wild-type eyes, wild-type body 418

round eyes, wild-type body 19

wild-type eyes, white body 16

round eyes, white body 426

a. What phenotypic proportions would be expected if the genes for round eyes and white body were located on different chromosomes?

b. What is the percent recombination between the genes for round eyes and white body?

Expert Solution

2. Parental cross rere wbwb x re+re+ wb+wb+

Parental gametes re wb (From rere wbwb) & re+ wb+ (From re+re+ wb+wb+)

F1 re+re wb+wb

Test cross re+re wb+wb x rere wbwb

Test cross gametes re+ wb+, re+ wb, re wb+ & re wb (From re+re wb+wb); re wb (From rere wbwb)

a) When genes are located on the different chromosomes, they will assort independently. In this case, F1 heterozygous individuals are testcrossed & genes are assorted independently. As a result, we will expect to observe 1:1:1:1 phenotypic ratio for the given four phenotypes- (wild type eyes, wild type body), (round eyes, wild type body), (wild type eyes, white body) & (round eyes, white body).

b) Parental progeny are always highest in numbers. So, (wild type eyes, wild type body) & (round eyes, white body) are parental (non-recombinant) traits; (round eyes, wild type body) & (wild type eyes, white body) are recombinant traits. It can be also seen from the test cross gametes.

Now, recombination frequency = (Number of recombinant progeny / Total number of progeny) x 100%

So, recombination frequency between the round eyes & white body genes = [(19+16) / (418+19+16+426)] x 100% = 3.98% (Up to 2 decimals)

gladiator answered 2 years ago

A female fruit fly with the recessive mutant phenotype of white eyes and miniature wings is...

A female fruit fly with the recessive mutant phenotype of white eyes and miniature wings is mated with a male possessing the wild-type phenotype of red eyes and normal wings. Among the F1s, all the females are wild-type while all the males exhibit the mutant phenotype. The F2s resulting from a test cross exhibit predominantly (63%) parental phenotypes. How do you explain these results?

Why do yellow gene mutations impact body color in the fly? Do the two mutant alleles...

Why do yellow gene mutations impact body color in the fly? Do the two mutant alleles from a female yellow fly need to be the same mutation (same allele)?

In Drosophila the recessive alleles for white eyes is X-linked (normal eye color is red) and...

In Drosophila the recessive alleles for white eyes is X-linked (normal eye color is red) and the recessive allele for vestigial wings is autosomal. A female heterozygous for both of these traits is crossed with a white-eyed vestigial male. What proportion of the FEMALE progeny will be white-eyed with vestigial wings.? (a) 100 % (b) 75 % (c) 50 % (d) 25 % (e) 0 %

Question 9 [10 marks / 10 minutes] Suppose there are two different mutant alleles of the...

Question 9 [10 marks / 10 minutes] Suppose there are two different mutant alleles of the same gene. Sequence analysis shows that both alleles are single nucleotide substitutions, and that different nucleotide positions within the gene are affected in each allele. Phenotypic analysis shows that one allele is a null allele, and the other is dominant negative (antimorphic). Explain what this information reveals about the two mutations. Give a hypothesis for how these two mutant alleles could show such markedly...

In a bird species, the shape of the beak is encoded by ONE SINGLE locus with TWO co-dominant alleles N^a and Nz.

In a bird species, the shape of the beak is encoded by ONE SINGLE locus with TWO co-dominant alleles N^a and Nz. N^a gives long beak in double dose, while individuals who are homozygous for N^z have short beak. In a population, the following genotype frequencies were observed: N^a N^a = 0.5N^a N^z = 0.3N^z N^z = 0.2 a) Assume a total of 600 individuals in the population. Set up a hypothesis, will the frequency be in Hardy-Weinberg equilibrium?...

Two pairs of alleles interact to determine cyanide production in different strains of white clover: some...

Two pairs of alleles interact to determine cyanide production in different strains of white clover: some strains have high cyanide content, while others have low cyanide content. When a true-breeding strain (“H”) that produces high amounts of cyanide was crossed to a true-breeding strain (“L”) that produces low amounts of cyanide, the F1 plants all had high cyanide content. When the F1 plants were crossed to each other, the following resulted: Low cyanide content: 350 plants High cyanide content:...

2) If a gene locus for has two alleles and p is .33. What is q?...

2) If a gene locus for has two alleles and p is .33. What is q? 3) In a population of mice, coat color is controlled by a gene locus with two alleles, B and W. BB mice are brown, BW are tan and WW mice are white. What is this type of inheritance called? In this population there are 20 brown mice 15 tan mice and 30 white mice. Calculate p and q for this population where p =...

An urn has 2 red, 5 white, and 4 blue balls in an urn and two...

An urn has 2 red, 5 white, and 4 blue balls in an urn and two are drawn one after another without replacement. What is the probability that the two balls are both red given that they are the same color?

Suppose box 1 has four black marbles and two white marbles, and box 2 has two...

Suppose box 1 has four black marbles and two white marbles, and box 2 has two black marbles and five marbles. If you picked one marble from one of the two boxes at random, what it the probability that you picked from box 1 given that the marble you picked is black? A raffle has 5000 tickets with the following prizes: 1 ticket has $2000 prize, 10 tickets have $200 prize, and 20 tickets have $50 prize and 500 tickets...

2. Complete the following cost schedule. Round to two decimal places. Answer the questions below ...

2. Complete the following cost schedule. Round to two decimal places. Answer the questions below after completing the table. Rate of Output Total Cost Marginal Cost Average Fixed Cost Average Variable Cost Average Total Cost 0 $1000 1 1200 2 1450 3 1750 4 2100 5 2500 a. Use the cost data above to graph the ATC and MC curves. b. At what output rate is ATC minimized?