Chapter 14

Question 1

Character

Answer 1

An observable heritable feature that may vary among individuals

Question 2

Trait

Answer 2

One of two or more detectable variants in a genetic character.

Question 3

True-breeding

Answer 3

Referring to organisms that produce offspring of the same variety over many generations of self-pollination.

Question 4

Hybridization

Answer 4

In genetics, the mating, or crossing, of two true-breeding varieties.

Question 5

P generation

Answer 5

The true-breeding (homozygous) parent individuals from which F1 hybrid offspring are derived in studies of inheritance; P stands for “parental”

Question 6

F1 Generation

Answer 6

The first filial hybrid offspring arising from a parental (P generation) cross.

Question 7

F2 generation

Answer 7

The offspring resulting from interbreeding of the hybrid F1 generation

Question 8

Allele

Answer 8

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

Question 9

Dominant allele

Answer 9

An allele that is fully expressed in the phenotype of a heterozygote.

Question 10

Recessive allele

Answer 10

An allele whose phenotypic effect is not observed in a heterozygote.

Question 11

Law of segregation

Answer 11

Mendel’s first law, stating that the two alleles in a pair segregate (separate from each other) into different gametes during gamete formation.

Question 12

Punnett Square

Answer 12

A diagram used in the study of inheritance to show the predicted genotypic results of random fertilization in genetic crosses between individuals of known genotype.

Question 13

Homozygous

Answer 13

Having two identical alleles for a given gene

Question 14

Heterozygous

Answer 14

Having two different alleles for a given gene

Question 15

Phenotype

Answer 15

The observable physical and physiological traits of an organism, which are determined by its genetic makeup.

Question 16

Genotype

Answer 16

The genetic makeup, or set of alleles, of an organism

Question 17

Testcross

Answer 17

Breeding an organism of unknown genotype with a homozygous recessive individual to determine the unknown genotype. The ratio of phenotypes in the offspring reveals the unknown genotype.

Question 18

Monohybrids

Answer 18

An organism that is heterozygous with respect to a single gene of interest.

Question 19

Monohybrid cross

Answer 19

A cross between two organism that are heterozygous for the character being followed.

Question 20

Dihybrid

Answer 20

An organism that is heterozygous with respect to two genes of interest.

Question 21

Law of independent assortment

Answer 21

Mendel’s second law, stating that each pair of alleles segregates, or assorts, independently of each other pair during gamete formation

Question 22

Multiplication rule

Answer 22

A rule of probability stating that the probability of two or more independent events occurring together can be determined by multiplying their individual probabilities.

Question 23

Addition Rule

Answer 23

A rule of probability stating that the probability of any one of two or more mutually exclusive events occurring can be determined by adding their individual probabilities.

Question 24

Complete dominance

Answer 24

The situation in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable.

Question 25

Incomplete dominance

Answer 25

The Situation in which the phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele.

Question 26

Codominance

Answer 26

The situation in which the phenotypes of both alleles are exhibited in the heterozygote because both alleles affect the phenotype in separate, distinguishable ways.