Chapter 12

Question 1

monohybrid cross

Answer 1

crossing of one allele

Question 2

dihybrid cross

Answer 2

crossing of two alleles

Question 3

homunculus belief

Answer 3

belief sperm contained little people

Question 4

everything from egg belief

Answer 4

females controlled all traits

Question 5

parental heredity belief

Answer 5

males controlled all traits

Question 6

gregor model

Answer 6

father of genetics

Question 7

law of segregation

Answer 7

gametes can only carry one allele for a gene

Question 8

law of independent assortment

Answer 8

alleles are not linked , equally likely

Question 9

phenotype

Answer 9

observable traits from organism

Question 10

genotype

Answer 10

organisms underlying genetic makeup

Question 11

homozygous alleles

Answer 11

two identical alleles on gene

Question 12

parent generation

Answer 12

true breeding

Question 13

first filial generation

Answer 13

offspring cross between parents

Question 14

second filial generation

Answer 14

produced by crossing first filial generation

Question 15

cross sibs mating

Answer 15

mating between siblings

Question 16

backcross mating

Answer 16

mating offspring back to the parent

Question 17

self cross mating

Answer 17

crossing plant or thing with itself

Question 18

true breeding

Answer 18

parents w same traits produce same trait offspring

Question 19

dominant allele

Answer 19

masks recessive, determines appearance

Question 20

rationale

Answer 20

determines whether dominant trait is from heterozygous or homozygous

Question 21

recessive trait

Answer 21

trait that is masked by dominant but genetically carried

Question 22

trait

Answer 22

characteristic

Question 23

alleles

Answer 23

versions of a gene

Question 24

heterozygous traits

Answer 24

alleles for same trait differ

Question 25

zygote

Answer 25

diploid cell produced by fertilization

Question 26

gene

Answer 26

place in DNA strand that codes info

Question 27

locus

Answer 27

specific place of gene

Question 28

reciprocal cross

Answer 28

previous cross repeated , phenotypic trait reversed by sex

Question 29

wildtype allele

Answer 29

most common allele in population

Question 30

mutant allele

Answer 30

rare allele in population

Question 31

multiplicative law

Answer 31

multiply independent random events

Question 32

additive law

Answer 32

sum of random events

Question 33

crossover

Answer 33

recombination , two chromosomes exchange segement of material

Question 34

variable expression

Answer 34

multiple effects of one trait

Question 35

lethal alleles

Answer 35

kill the person who inherits it

Question 36

epistasis

Answer 36

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

Question 37

hemophilia sex

Answer 37

linked, recessive disorder

Question 38

sex chromosomes

Answer 38

Xx or Xy

Question 39

sex-linked traits

Answer 39

traits specifically on sex chromosomes

Question 40

what do punnet squares do?

Answer 40

identify parental genotypes, results in 3:1 ratio

Question 41

mendell and his success

Answer 41

true bred peas, avoided unexpected traits, large quantities cultivated and evaluted

Question 42

hybridizations

Answer 42

mating two true bred indv. with diff traits from one another