Unit 5 Genetics

Question 1

Trait

Answer 1

Each variant for a character

Question 2

True-breeding

Answer 2

Over many generations, it had produced only the same variety as the parent

Question 3

Hybridization

Answer 3

Mating of two true-breeding parents with at least one differing characteristic.

Question 4

Allele

Answer 4

Alternative versions of a gene

Question 5

Law of segregation

Answer 5

States that the two alleles for a heritable character separate from each other during gamete formation and end up in different gametes

Question 6

Phenotype

Answer 6

An organisms appearance or observable traits

Question 7

Genotype

Answer 7

An organisms genetic makeup

Question 8

Testcross

Answer 8

Breeding an organism of unknown genotype with a recessive homozygote

Question 9

Monohybrid Cross

Answer 9

Cross of two heterozygotes (Rr)

Question 10

Dihybrid Cross

Answer 10

A cross between two individuals, concentrating on two definable traits

Question 11

Law of Independent Assortment

Answer 11

States that each pair of alleles segregates independently of each other pair of alleles during gamete formation

Question 12

Multiplication Rule

Answer 12

States that to determine the probability, we multiple the probability of one event by the probability of the other event

Question 13

Addition Rule

Answer 13

States that the probability that any one of two or more mutually exclusive events will occur is calculated by adding their individual probabilities

Question 14

Complete dominance

Answer 14

The offspring always looked like one of the two parental variety because one allele in the pair showed __________

Question 15

Incomplete dominance

Answer 15

Three or more potential varieties from crossing two parents

Question 16

Co-dominance

Answer 16

Two alleles each affect the phenotype in separate, distinguishable ways

Question 17

Pleiotropy

Answer 17

Most genes have multiple phenotypic effects called…

Question 18

Epistasis

Answer 18

the phenotypic expression of a gene a one locus alters that of a gene at a second locus

Question 19

Polygenic Inheritance

Answer 19

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

Question 20

Carrier

Answer 20

Heterozygous person can transmit the recessive allele to their offspring without themselves having the trait

Question 21

Gametes

Answer 21

reproductive cells; egg and sperm

Question 22

homologous chromosomes

Answer 22

Chromosomes that have the same sequence of genes, that have the same structure, and that pair during meiosis.

Question 23

Pedigree

Answer 23

A diagram that shows the occurrence of a genetic trait in several generations of a family.

Question 24

Punnett Square

Answer 24

A chart that shows all the possible combinations of alleles that can result from a genetic cross

Question 25

wildtype allele

Answer 25

most common allele in a population

Question 26

wildtype phenotype

Answer 26

most common phenotype

Question 27

dominant allele

Answer 27

an allele that is fully expressed in the phenotype of a heterozygote

Question 28

recessive allele

Answer 28

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

Question 29

Heterozygous

Answer 29

having two different alleles for a trait

Question 30

Homozygous

Answer 30

having two identical alleles for a trait

Question 31

F1 generation

Answer 31

offspring of the P generation

Question 32

P generation

Answer 32

Parental generation, the first two individuals that mate in a genetic cross

Question 33

F2 generation

Answer 33

The offspring of the F 1 generation

Question 34

sex-linked traits

Answer 34

A trait associated with a gene that is carried only by the male or female parent.

Question 35

Recombination

Answer 35

the genetic process by which one chromosome breaks off and attaches to another chromosome during reproductive cell division

Question 36

crossing over

Answer 36

exchange of genetic material between homologous chromosomes during prophase I of meiosis