Question

Question 5

2 pts

A couple decides that they want to have three daughters. What is the probability that this will actually occur?

  

1/4

   

1/16

   

1/8

   

1/2

Question 6

2 pts

Which of the following is incorrectly matched?

  

pleiotropy: a single allele contributes to several traits

   

multiple alleles: an individual acquires more than two alleles for a given trait

   

polygenic inheritance: several alleles contribute to a single trait

  

incomplete dominance: an allele is partially expressed and produces an intermediate phenotype

Question 7

2 pts

Beak color in a certain species of bird is controlled by a single gene. You mate a homozygous finch (with an orange beak) with a homozygous finch (with an ivory beak). All the offspring have pale, peach colored beaks. The most likely genetic explanation is _____.

  

a mutation occurred

   

multiple alleles

   

incomplete dominance

   

codominance

Question 8

2 pts

An allele known as BRCA1 is often found in women with breast and ovarian cancer. However, some women develop those cancers and do not have the BRCA1 allele. In addition, some women who have BRCA1 never develop breast or ovarian cancer. How can this be explained?

  

Something other than the allele must factor into whether cancer develops or not.

   

This must be an example of pleiotropy.

   

The BRCA1 allele must be dominant.

   

These types of cancers are in no way associated with specific alleles.

Question 9

2 pts

Hemophilia is a sex-linked disorder. Which is the best prediction of the offspring if the mother is a carrier and the father has hemophilia?

Fifty percent of the sons will have hemophilia, and 50% of the daughters will have hemophilia.

  

All sons will have hemophilia and all daughters will be normal.

   

All sons and daughters will have hemophilia.

  

Twenty-five percent of the daughters will have hemophilia, and all the sons will have hemophilia.

  

All sons and all daughters will be normal.

Answer 1