Lecture 10

Question 1

Principle of Segregation

Answer 1

Alleles separate during meiosis

Question 2

Law of Independent Assortment

Answer 2

Alleles at one locus sort independently from alleles at another locus

Question 3

Recombination

Answer 3

Alleles sort into new combinations

Question 4

Crossing Over

Answer 4

Complete linkage of alleles leads to nonrecombinant gametes and nonrecombinant progeny; crossing over disrupts linked alleles and leads to recombinant gametes and recombinant progeny

Question 5

How do you calculate recombination frequency?

Answer 5

Recombination Frequency = (# of recombinations /total # of progeny) x 100

Question 6

Coupling Configuration (Cis Configuration) of Linked Genes

Answer 6

One chromosome contains both wild-type alleles, one chromosome contains both mutant alleles

Question 7

Repulsion Configuration (Trans Configuration) of Linked Genes

Answer 7

Wild-type allele and mutant allele are found on the same chromosome

Question 8

Coefficient of Coincidence

Answer 8

of observed double crossovers/# of expected double crossovers

Question 9

Interference

Answer 9

1 - Coefficient of Coincidence

Question 10

Haplotype

Answer 10

Set of DNA variations, or polymorphisms, that tend to be inherited together

Question 11

Centimorgan

Answer 11

Unit for measuring genetic linkage; abbreviated as cM or map unit (m.u.)

Question 12

Genetic Maps

Answer 12

Illustrate the arrangement of genes and DNA markers on a chromosome and the relative distances between positions are calculated using recombination frequencies

Question 13

Physical Maps

Answer 13

Illustrate the arrangement of genes and DNA markers on a chromosome based on the actual number of nucleotide pairs between loci

Question 14

What is somatic cell hybridization used for?

Answer 14

Used to determine which chromosome contains a gene of interest

Question 15

What is deletion mapping used for?

Answer 15

Used to determine the chromosomal location of a gene; an individual homozygous for a recessive mutation in the gene of interest is crossed with an individual heterozygous for a deletion

Question 16

What is fluorescence-in-situ hybridization used for?

Answer 16

Another technique used for determining the chromosomal location of a gene

Question 17

Genome-wide Association Studies

Answer 17

Examine genetic (sequence) variants across the entire genome to find those that are associated with a trait or a disease; each individual differs by million of sequence variants scattered across the genome; usually identifies variants that are higher in proportion in the study group, so the next step is to establish biological relevance

Variants associated with a trait often occur in noncoding parts of the genome