Chapter 14: Mendel and the Gene Idea

Question 1

Homozygous

Answer 1

having two identical alleles of a particular gene (ex. AA, aa)

Question 2

Heterozygous

Answer 2

having two different alleles of a particular gene (ex. Aa)

Question 3

Recessive Allele

Answer 3

an allele whose phenotype effect is not observed (ex. a)

Question 4

Dominant Allele

Answer 4

an allele whose phenotype effect is fully expressed (ex. A)

Question 5

Allele

Answer 5

any of the alternative versions of a gene that may produce distinguishable phenotypic effects

Question 6

Character

Answer 6

an observable heritable feature that may vary among individuals

Question 7

Phenotype

Answer 7

A descriptive of an organisms traits

Question 8

Genotype

Answer 8

A descriptive of its genetic makeup

Question 9

F1 Generation

Answer 9

the first filial, hybrid (heterozygous) offspring arising from a parental (P generation) cross

Question 10

F2 Generation

Answer 10

the offspring resulting from interbreeding (self pollination) of the hybrid in F1 generation

Question 11

Law of segragation

Answer 11

stating that two alleles in a pair separate from each other into different gametes during gamete formation

Question 12

Law of Independent Formation

Answer 12

stating that each pair of alleles assorts independently of each other pair during gamete formation

Question 13

Pleiotropic

Answer 13

the ability of a single gene to have multiple effects

Question 14

Epistatis

Answer 14

a type of gene interaction in which the phenotypic expression of one gene alters that of another independently inherited gene

Question 15

Polygenic Inheritance

Answer 15

an additive effect of two or more genes on a single phenotypic character

Question 16

Individuals who lack the disorder are…

Answer 16

either homozygous dominant or heterozygous

Question 17

Co-dominant

Answer 17

a type of inheritance in which alleles of the same gene are expressed separately to yield different traits in an individual

Question 18

Incomplete Dominance

Answer 18

a form of gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype

Question 19

True breeding

Answer 19

an organism that always passes down certain phenotypic traits to its offspring of many generations

Question 20

Test cross

Answer 20

a cross between an individual displaying a recessive trait and one displaying a dominant trait to determine whether or not the dominant trait is heterozygous

Question 21

Monohybrid cross

Answer 21

single trait crosses (ex. AA x Aa)

Question 22

Dihybrid cross

Answer 22

Double trait crosses (ex. AAbb x AaBB)