I think the anser is d that what i think Is
Answer:
Man encourages his sister to see a genetic counselor in order to find out that she has the genetic disease or not.
Explanation:
Cystic fibrosis is genetic disease that can transfer from parents to their offspring. This is a very dangerous disease which decrease the life span of patient and the patient die in early stages of life. The man with Cystic fibrosis disease encourage his sister to go to the genetic counselor to find out the presence of disease in her blood because she is planning a baby and we know that this is a hereditary disease so if she has this disease it will transfer to her child.
1.What is the probability that a sperm from the father will contain the PKU allele?
Probability = ½
2.What is the probability that an egg from the mother will contain the PKU allele?
Probability = ½
3.What is the probability that their next child will have PKU?
Probability = ¼ (because each parent has ½ chance ½ X ½ = ¼)
4.What is the probability that their next child will be heterozygous for the PKU gene?
Probability = ½ (because each parent has ½ chance of donating the ‘P’ allele and ½ chance of donating the ‘p’ allele (½ x ½) + (½ x ½) = ½
Answer:
The options
a. New combinations of genes yielding genotypes of greater fitness
b. Few heterozygotes because of underdominance
c. Frequency-dependent selection, leading to fluctuations in fitness
d. Heterozygotes with greater fitness, owing to overdominance
e. A random assortment of genotypes because of genetic drift
The CORRECT ANSWER IS b.
b. Few heterozygotes because of under dominance
Explanation:
In genetics, underdominance (at times called "negative overdominance") is the opposite of overdominance.
It is the selection against the heterozygote, that leads to disruptive selection and divergent genotypes. It occurs in cases of inferior and reduced fitness (As in our case study, it is the different chromosomal fusions and inversions)
of the heterozygotic genotype to the dominant or recessive homozygotic genotype. It is unstable as it causes fixation of either allele.
Another example is the African butterfly species Pseudacraea eurytus, which makes use of Batesian mimicry to avoid predation. This species carries two alleles that gives a coloration that is alike to a different local butterfly species that is harmful to its predator. The butterflies who are heterozygous for this trait are observed to be intermediate in coloration and thus encounter an higher risk of predation and a decrease in the total fitness.
