EXAM 3 Study Guide

Question 1

What is the law of segregation?

Answer 1

The principle that alleles for a trait separate during gamete formation.

Question 2

What is a monohybrid cross?

Answer 2

A genetic cross between individuals that differ in one trait.

Question 3

What is a dihybrid cross?

Answer 3

A genetic cross between individuals that differ in two traits.

Question 4

What is a test cross?

Answer 4

A cross between an individual with an unknown genotype and a homozygous recessive individual.

Question 5

What statistical test is used to analyze linkage?

Answer 5

Chi-squared test.

Question 6

What does recombination refer to in genetics?

Answer 6

The production of non-parental types of gametes due to crossing over.

Question 7

How is map distance calculated?

Answer 7

Percent recombination.

Question 8

What is triple cross mapping used for?

Answer 8

To determine gene order and map distances between pairs of genes.

Question 9

What does negative interference indicate?

Answer 9

More recombination than expected.

Question 10

What is sex-linkage?

Answer 10

Inheritance patterns associated with genes located on sex chromosomes.

Question 11

What is pseudoautosomal inheritance?

Answer 11

Inheritance where both sex chromosomes carry the same gene.

Question 12

What is the function of the SRY gene?

Answer 12

Determines male sex characteristics.

Question 13

What does ZZ/ZW refer to?

Answer 13

A type of sex determination system.

Question 14

What are the characteristics of a recessive pedigree?

Answer 14

Traits that skip generations and appear in offspring of unaffected parents.

Question 15

What are the characteristics of a dominant pedigree?

Answer 15

Traits that appear in every generation and affect both sexes equally.

Question 16

What is a sex-linked trait?

Answer 16

A trait associated with genes on sex chromosomes.

Question 17

What is mitochondrial inheritance?

Answer 17

Inheritance of traits through maternally derived mitochondria.

Question 18

What is Y chromosome inheritance?

Answer 18

Traits inherited through the paternally derived Y chromosome.

Question 19

What is lethality in genetics?

Answer 19

A condition where certain genotypes result in death, often conditional.

Question 20

What is incomplete dominance?

Answer 20

When a heterozygote exhibits a phenotype that is intermediate between the two homozygotes.

Question 21

What are multiple alleles?

Answer 21

More than two alleles exist for a given gene, such as in rabbit coat color.

Question 22

What is codominance?

Answer 22

A situation where both alleles express their traits equally, as in the ABO blood group.

Question 23

What does overdominance refer to?

Answer 23

When heterozygotes have a fitness advantage over homozygotes.

Question 24

What is incomplete penetrance?

Answer 24

When not all individuals with a genotype express the expected phenotype.

Question 25

What is expressivity?

Answer 25

The degree to which a genotype is expressed in an individual's phenotype.

Question 26

What is pleiotropy?

Answer 26

A single gene influencing multiple phenotypic traits.

Question 27

What are gene interactions?

Answer 27

The effects of genes on one another, including environmental influences.

Question 28

What is sex-influenced inheritance?

Answer 28

Traits that are expressed differently in males and females.

Question 29

What is sex-limited inheritance?

Answer 29

Traits that are expressed only in one sex, such as ovaries vs testes.

Question 30

What are genotype frequencies?

Answer 30

The relative frequency of different genotypes in a population.

Question 31

What is the Hardy-Weinberg equation used for?

Answer 31

To predict genotype frequencies in a non-evolving population.

Question 32

What does QTL mapping stand for?

Answer 32

Quantitative Trait Locus mapping.