April 4th (256-263)

Question 1

Chromosome theory of inheritance

Answer 1

formed by Sutton and Boveri; asserts that the hereditary factors called genes are located on chromosomes.

Question 2

Heredity

Answer 2

meaning inheritance of the transmission oft traits from parents to offspring.

Question 3

trait

Answer 3

any characteristic of an individual, ranging from height to the primary structure of a particular membrane protein.

Question 4

Blending inheritance

Answer 4

claimed that the traits observed in a mother and father blend together to form the traits observed in their offspring. As a result, an offspring’s traits are intermediate between the mother’s and father’s traits. false

Question 5

Inheritance of acquired characters

Answer 5

claimed that traits present in parents are modified, through use, and passed on to their offspring in the modified form. false

Question 6

model organism

Answer 6

a species that is used for research because it is practical (available in many recognizable traits, control mating for ex) and because conclusions drawn from studying it turn out to apply to many other species as well.

Question 7

self-fertilization

Answer 7

a flower’s pollen falls on the female reproductive organ of that same flower.

Question 8

cross-fertilization or cross

Answer 8

Mendel prevented self fertilization by cutting off the male reproductive organs before any pollen formed so he could transfer pollen from the plants that he wanted to w/ a brush.

Question 9

phenotype

Answer 9

the observable traits of an individual, such as the shape of a pea seed.

Question 10

gene

Answer 10

a hereditary factor that influences a particular trait

Question 11

allele

Answer 11

a particular form of a gene.

Question 12

genotype

Answer 12

a listing of the alleles in an individual.

Question 13

homozygous

Answer 13

having two of the same allele.

Question 14

heterozygous

Answer 14

having two different alleles.

Question 15

dominant allele

Answer 15

an allele that produces its phenotype in heterozygous and homozygous form.

Question 16

recessive allele

Answer 16

an allele that produces its phenotype in homozygous form.

Question 17

pure line

Answer 17

individuals of the same phenotype that, when crossed, always produce offspring with the same phenotype (meaning they are homozygous for the gene in question).

Question 18

hybrid

Answer 18

offspring from crosses between homozygous parents with different genotypes.

Question 19

reciprocal cross

Answer 19

a cross in which the phenotypes of the male and female are reversed compared with a prior cross.

Question 20

testcross

Answer 20

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

Question 21

x-linked

Answer 21

referring to a gene located on the X chromosome. (different patterns of inheritance in males and females)

Question 22

y-linked

Answer 22

referring to a gene located on the Y chromosome. (determine male-specific development).

Question 23

autosomal

Answer 23

referring to a gene located on any non-sex chromosome (an autosome) or a trait determined by an autosomal gene. (Mendel only studied these)

Question 24

Mendel’s first experiments

Answer 24

consisted of crossing pure lines that differed in one trait (round vs. wrinkled seeds)

Question 25

parental generation

Answer 25

adults initially used in an experiment

Question 26

progeny/F1 generation

Answer 26

the offspring of the parental generation

Question 27

monohybrid cross

Answer 27

mating between parents that each carry two different genetic determinants for the same trait.

Question 28

dominant alleles and recessive alleles

Answer 28

dominant doesn’t mean a higher fitness and recessive doesn’t mean a lower fitness.

dominant and recessive only identify which phenotype is observed in an individual carrying two different genetic determinants for a given trait.

Question 29

particulate inheritance

Answer 29

proposed by Mendel after first 2 hypotheses didn’t hold: heredity determinants maintain their integrity from generation to generation. Instead of blending together, they act as discrete entities or particles.

Question 30

principle of segregation

Answer 30

to explain the reappearance of the recessive phenotype and the characteristic 3:1 ratio of phenotypes in F2 individuals, Mendel reasoned that the two members of each gene pair must segregate into different gamete cells during the formation of eggs and sperm so therefore each gamete contains one allele of each gene.

Question 31

genetic model

Answer 31

refers to a set of hypotheses that explains how a particular trait is inherited; these hypotheses are sometimes referred to as Mendel’s rules.