Vocab

Question 1

Dominant allele

Answer 1

If the alleles of an inherited pair differ, then one determines the organism’s appearance and is called the dominant allele.

Question 2

Recessive allele

Answer 2

The other has no noticeable effect on the organism’s appearance and is called the recessive allele.

Question 3

Phenotype

Answer 3

appearance or expression of a trait.

Question 4

Genotype

Answer 4

genetic makeup of a trait.

Question 5

Law of Segregation

Answer 5

A sperm or egg carries only one allele for each inherited character because allele pairs separate (segregate) from each other during the production of gametes. This statement is called the law of segregation.

Question 6

Punnette square

Answer 6

shows the four possible combinations of alleles that could occur when these gametes combine.

Question 7

Locus

Answer 7

is the specific location of a gene along a chromosome.

Question 8

Dehybrid

Answer 8

is a mating of parental varieties that differ in two characters

Question 9

Law of independent assortment

Answer 9

suggested that the inheritance of one character has no

effect on the inheritance of another, and suggested that the dihybrid cross is the equivalent to two monohybrid crosses.

Question 10

Test cross

Answer 10

the mating between an individual of unknown genotype and a homozygous recessive individual.

Question 11

Rule of multiplication

Answer 11

the probability is the product of the probabilities for each event.

Question 12

Rule of addition

Answer 12

The probability that an event can occur in two or more alternative ways is the sum of the separate probabilities

Question 13

Wild type traits

Answer 13

those prevailing in nature, are not necessarily specified by dominant allel

Question 14

Pedigree

Answer 14

shows the inheritance of a trait in a family through
multiple generations,
– demonstrates dominant or recessive inheritance, and
– can also be used to deduce genotypes of family members.

Question 15

Recessive inheritance

Answer 15

– two recessive alleles are needed to show disease,
– heterozygous parents are carriers of the disease-causing allele, and
– the probability of inheritance increases with inbreeding, mating between close relatives.

Question 16

Inbreeding

Answer 16

mating between close relatives.

Question 17

Dominant inheritance

Answer 17

one dominant allele is needed to show disease and

– dominant lethal alleles are usually eliminated from the population.

Question 18

cystic fibrosis

Answer 18

The most common fatal genetic disease in the United States. resulting in excessive thick mucus secretions.

Question 19

Achondroplasia

Answer 19

resulting in dwarfism,

Question 20

Hunningtons

Answer 20

degenerative disorder of the nervous system.

Question 21

Complete dominance

Answer 21

Mendel’s pea crosses always looked like one of the parental varieties

Question 22

Incomplete dominance

Answer 22

When for some characters, the appearance of F1 hybrids falls between the phenotypes of the two parental varieties.
neither allele is dominant over the other and
– expression of both alleles occurs.

Question 23

hypercholesterolemia

Answer 23

dangerously high levels of cholesterol occur in the blood and
– heterozygotes have intermediately high cholesterol levels.

Question 24

Con dominance

Answer 24

The A and B alleles are both expressed in heterozygous individuals neither allele is dominant over the other and
– expression of both alleles is observed as a distinct phenotype in the heterozygous individual.
– AB blood type is an example of codominance.

Question 25

Pleiotropy

Answer 25

when one gene influences many characteristics.

Question 26

Polygenic inheritance

Answer 26

in which a single phenotypic character results from the additive effects of two or more genes.

Question 27

chromosome theory of inheritance

Answer 27

genes occupy specific loci (positions) on chromosomes
and
– chromosomes undergo segregation and independent assortment during meiosis.

Question 28

linked genes,

Answer 28

are located close together on the same chromosome and

– tend to be inherited together.

Question 29

recombination frequency.

Answer 29

Linked alleles can be separated by crossing over, forming recombinant gametes.

Question 30

sex chromosomes,

Answer 30

designated X and Y,

– that determine an individual’s sex.

Question 31

Sex-linked genes

Answer 31

are located on either of the sex chromosomes.

Question 32

Alleles

Answer 32

Are alternative versions of genes that account for variations in inherited characters.

Question 33

Homozygous

Answer 33

Genotype has identical alleles.

Question 34

Heterozygous

Answer 34

Genotype has two different alleles.

Question 35

Monohybrid Cross

Answer 35

A cross between two individuals differing in a single character.

Question 36

Character

Answer 36

A heritable feature that varies among individuals like flower color.

Question 37

Trait

Answer 37

Each variant for a character such as purple or white.

Question 38

Hybrid

Answer 38

The offspring of two different variates.