Answer the following questions.... My answers are as follows.... False, False, T

Question

Answer the following questions....

My answers are as follows.... False, False, True, and C.

1. A dominant allele will always increase in frequency over time.

2. When a gene has two alleles, the allele frequencies in a population automatically move toward an equilibrium of 50:50, then stay there.

3. All else being equal, alleles associated with higher reproductive sucess increase in frequency more so than other alleles.

4. Flower color in Linanthus parryae is controlled largely by a single gene with two alleles, Individuals with genotype BB or Bb are blue; individuals with genotype bb are white. Linanthus parryae grows in patches in the desert. Some patches have only blue individuals, some have only white, and some are mixed. Based only on this information, which explaination is possible? Check all that apply.

a. The difference among patches is due to natural selection. Blue individuals have higher reproductive success in some patches, white plants have higher succes in some patches, and the two colors do equally well in some patches

b. The difference among patches is due to the founder effect. Some patches were founded by homozygous blue individuals, some patches by white individuals, and some patches by individuals carrying both alleles

c.The difference among patches is due to genetic drift. Particularly if population size in a patch is small, one color or the other might be lost simply as a result of chance events, such as drought or herbivory

My answers are as follows.... D and B

5. Bollworms experience a trade-off between development time on normal cotton and survival on Bollgard cotton. Why is this trade-off important to the management of Bt-resistance?

a. Because this trade-off is the reason that Bt-resistance is heritable

b. Becasue without this trade-off, pink bollworms would have no need to become resistance to Bt-toxin

c. Because longer overall development time on Bollgard cotton means that individual pink bollworms develop resistance to Bt-toxin more slowly

d. Because if Bt-resistance bollworms did just as well as susceptible bollworms on normal cotton, resistance would tend to evolve in any field containing even a small portion of Bollgard

6. Farmers growing Bollgard cotton should reserve some space in their field for normal cotton because:

a. Normal cotton has higher yield

b. A refuge allows Bt-susceptible bollworms to survive, thereby reducing the fitness advantage of being resistant

c. Planting normal cotton is the only way to find out whether a field is susceptible to infestation by pink bollworms

d. Normal cotton is less expensive

7. The boll weevil, an insect native to Mexico and Central America, is another pest of commercial cotton. When chemical insecticides were first discovered, they proved highly effective in controlling boll weevil outbreaks. Within a few decades, however, may boll weevil populations were resistant. Using what you've learned in this chapter, explain how the boll weevil populations changed.

Not 100% about this question.

Explanation / Answer

1. A dominant allele will always increase in frequency over time : False

2. When a gene has two alleles, the allele frequencies in a population automatically move toward an equilibrium of 50:50, then stay there. : False

3. All else being equal, alleles associated with higher reproductive sucess increase in frequency more so than other alleles. : TRUE

4.
b. The difference among patches is due to the founder effect. Some patches were founded by homozygous blue individuals, some patches by white individuals, and some patches by individuals carrying both alleles

5.
d. Because if Bt-resistance bollworms did just as well as susceptible bollworms on normal cotton, resistance would tend to evolve in any field containing even a small portion of Bollgard

6.
b. A refuge allows Bt-susceptible bollworms to survive, thereby reducing the fitness advantage of being resistant

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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