Mendel and the gene terminology

Question 1

gene

Answer 1

hereditary factor that influences a particular trait

Question 2

genotype

Answer 2

a listing of the alleles of particular genes in an individual

Question 3

phenotype

Answer 3

an individual’s observable traits

Question 4

homozygous

Answer 4

having 2 of the same allele

Question 5

dominant allele

Answer 5

allele that produces phenotype in heterozygous/homozygous genotypes

Question 6

recessive allele

Answer 6

allele that produces phenotype only in homozygous genotype

Question 7

pure line

Answer 7

individuals of the same phenotype that always produce offspring with the same phenotype when crossed

Question 8

hybrid

Answer 8

offspring from crosses between homozygous parents with different genotypes

Question 9

reciprocal cross

Answer 9

A cross of a homozygous recessive individual and an individual with the dominant phenotype but unknown genotype

Question 10

test cross

Answer 10

a cross of a homozygous recessive individual and an individual with the dominant phenotype but unknown genotype

Question 11

X-linked

Answer 11

gene located on X chromosome

Question 12

Y-linked

Answer 12

gene located on Y chromosome

Question 13

Autosomal

Answer 13

gene located on any non-sex chromosome

Question 14

parental generation

Answer 14

individuals used in the initial cross

Question 15

Monohybrid cross

Answer 15

mate between parents that carry 2 different genetic determinants for the same trait

Question 16

Principle of segregation

Answer 16

2 members of each gene pair must segregate, each gamete contains one allele of each gene

Question 17

Mendel’s 5 main ideas

Answer 17

1. Genes have different alleles
2. Genes are particles of inheritance that don’t blend together
3. Each gamete has one copy of each gene
4. Males/females contribute equally to genotype of offspring
5. Some alleles are dominant to others

Question 18

dihybrid cross

Answer 18

mating between 2 individuals who are heterozygous for 2 traits

Question 19

principle of independent assortment

Answer 19

alleles of different genes are transmitted independently of one another

Question 20

Wild type

Answer 20

common phenotype

Question 21

mutant

Answer 21

unusual phenotype due to mutation

Question 22

Multiple allelism

Answer 22

existence of more than 2 common alleles for a locus

Question 23

Codominance

Answer 23

both alleles show their affects but do not blend (red and white spots on Roan cow)

Question 24

Incomplete dominance

Answer 24

both alleles show their affects and blend (pink flower comes from red and white flower)

Question 25

Pleiotropic

Answer 25

gene that influences many traits

Question 26

gene-gene interaction

Answer 26

phenotype associated with an allele depends on which alleles of another gene are present

Question 27

gene-environment interaction

Answer 27

two different genotypes respond to environmental variation in different ways

Question 28

polygenic inheritance

Answer 28

many genes influence one trait

Question 29

autosomal recessive

Answer 29

two copies of an abnormal gene must be present in order for the disease or trait to develop (sickle cell); 1/4 of offspring are affected

Question 30

autosomal dominant

Answer 30

only one parent must be affected in order to have the gene passed on (Huntington’s); 1/2 of offspring are affected