BIO 206 CH:6

What is genetic mapping?

• The process of determining the locations of genes on chromosomes

• The process of sequencing DNA

• The process of cloning genes

• The process of editing genes.

In a linkage map, the distance between two loci is measured in ____.

• base pairs

• map units

• centimeters

• inches

What does the term 'synteny' refer to?

• A) Genes located on different chromosomes

• B) Genes located on the same chromosome

• C) Genes that are always inherited together

• D) Genes that mutate frequently.

Linked genes do not obey the law of independent assortment, unless ______ occurs between the two genes.

• mutation

• crossing over

• replication

• deletion

What happens to the offspring when linked genes do not undergo crossing over?

• Only parental offspring are produced.

• Only recombinant offspring are produced.

• 50% parental and 50% recombinant offspring are produced.

• More than 50% recombinant offspring are produced.

In Scenario 3, linked genes undergo crossing over. Fill in the blank: When crossing over occurs, testcrossed dihybrids produce ______ parental and <50% recombinant offspring.

• <50%

• >50%

• 50%

• 100%

Which of the following best describes the relationship between linkage and crossing over?

• A) Linkage increases the likelihood of crossing over.

• B) Linkage decreases the likelihood of crossing over.

• C) Linkage has no effect on crossing over.

• D) Linkage and crossing over are unrelated.

In linkage mapping, to determine if genes are linked, one must observe the phenotypic ratios. Fill in the blank: If the observed phenotypic ratio deviates significantly from the expected ratio, the genes are likely ________.

• A) unlinked

• B) linked

• C) mutated

• D) deleted

What is the expected result for the genetic cross resulting in 'y+ w+' in the table?

• 1159

• 17

• 12

• 1017

In the linkage mapping of Drosophila, y+ represents ______.

• yellow body

• gray body

• red eyes

• white eyes