Mendelian Genetics & Probability

Question 1

Allele

Answer 1

The possible variations in a gene

Question 2

Gene

Answer 2

Region of DNA that encodes for a specific protein (or RNA)

Question 3

Genotype

Answer 3

The pair of alleles in the organism

Question 4

Phenotype

Answer 4

The observable characteristics of an organism, or trait

Question 5

Test Cross

Answer 5

To determine the genotype of an organism, to be either heterozygous or homozygous dominant, breeding it with a homozygous recessive organism to see if the offspring are varied or identical

Question 6

True Breeding

Answer 6

A homozygous organism for a trait of interest, that when bred with itself or with another organism of the same genotype will produce offspring with the desired phenotype

Question 7

Multiple Alleles

Answer 7

Two or more versions of the same gene exist in a population

Question 8

Polymorphic Genes

Answer 8

more than one allele exists in more than 1% of the population

Question 9

Law of Segregation

Answer 9

Single gene:

The two alleles separate during fertilization and then randomly unite

Question 10

Monomorphic Genes

Answer 10

Only one allele exists in greater than 1% of the population, all other alleles are considered mutants

Question 11

Law of Independent Assortment

Answer 11

Two + Genes:

Different pairs of alleles separate independently of each other - allows for branching diagrams

Question 12

Incomplete Dominance

Answer 12

Two alleles are combined to form a new phenotype

Question 13

Co-dominance

Answer 13

When both alleles are expressed in organisms phenotype - can identify both alleles

Question 14

Wild-type vs Mutant

Answer 14

Wild type = allele that is present in >1% of the population

Mutant = allele that is present in <1% of the population

Question 15

Pleiotrophy

Answer 15

Multiple phenotypic effects from a single allele

Opposite of multifactorial inheritance

Question 16

Multifactorial Inheritance

Answer 16

phenotype is the sum of the interaction of multiple genes as well as with the environment

Question 17

Complementary Gene Action

Answer 17

2+ genes working together to express a phenotype

Question 18

Heterogenous Trait

Answer 18

mutation of a gene that still produces the same phenotype

Question 19

Complementation Testing

Answer 19

determines to see if mutations between parents are on the same genes

Question 20

Recessive epistasis

Answer 20

recessive alleles cover up the effect of another allele on a different gene
phenotypic ratio = 9:3:4

Question 21

Dominant epistasis

Answer 21

dominant alleles cover up the effect of an allele on a different gene
phenotypic ratio = 12:3:1

Question 22

Penetrance

Answer 22

% of the population that displays the expected trait - can be complete or incomplete

Question 23

Expressivity

Answer 23

intensity to which a genotype is expressed by the phenotype -variable expression

Question 24

Sex-Linked Traits

Answer 24

genes located on the x chromosome

Question 25

Sex-Limited Traits

Answer 25

affect a structure or process found on only one sex

Question 26

Sex-influenced Traits

Answer 26

occurs in both sexes, but at different frequencies

Question 27

Product Law

Answer 27

the probability that events will occur TOGETHER

Question 28

Sum Law

Answer 28

the probability of mutually exclusive events occuring