Inheritance

Question 1

genes

Answer 1

hereditary units found in chromosomes

Question 2

gametes

Answer 2

reproductive cells, eggs, sperm

Question 3

somatic cells

Answer 3

body cells (not gametes)

Question 4

locus

Answer 4

a gene’s specific location along the length of a chromosome

Question 5

karyotype

Answer 5

an ordered display of chromosomes from microscope images

Question 6

sex chromosomes

Answer 6

chromosomes that determine an indiviudal’s sex (X,Y)

Question 7

autosomes

Answer 7

chromosomes that aren’t sex chromosomes

Question 8

diploid cells

Answer 8

having 2 of each chromosome

Question 9

haploid cells

Answer 9

having 1 of each chromosome

Question 10

meiosis

Answer 10

the process that creates 4 haploid gametes from 1 germ cell

Question 11

phases of meiosis

Answer 11

meiosis 1 and meiosis 2

Question 12

homologous chromosomes

Answer 12

the pair of sister chromatids that attach to each other in prophase 1 of meiosis

Question 13

synapis

Answer 13

when the paired homologs become physically attached in prophase 1 of meiosis

Question 14

crossing over

Answer 14

a genetic swap between homologous non-sister chromatids in prophase 1

Question 15

chiasmata

Answer 15

a point where crossing over has occured

Question 16

recombinant chromosomes

Answer 16

the chromosomes that swapped genes during crossing over

Question 17

character

Answer 17

a heritable feature that varies among individuals; ex: eye color, height

Question 18

trait

Answer 18

each variant of a character; blue eyes, tall

Question 19

allele

Answer 19

a version of a gene

Question 20

phenotype

Answer 20

an organism’s observable traits

Question 21

genotype

Answer 21

an organism’s genetic makeup; affects phenotype

Question 22

law of segregation

Answer 22

the two alleles separate in gamete formation; you only get one allele from each parent

Question 23

heterozygous

Answer 23

having two differnt alleles

Question 24

homozygous

Answer 24

having two of the same allele

Question 25

true-breeding

Answer 25

crossing two homozygotes will always result in another homozygote

Question 26

dominant vs recessive

Answer 26

the expression of the dominant allele maks the phenotypic effect of the recessive allele

Question 27

law of independent assortment

Answer 27

the pair of alleles for a given gene segregates independently of the pair of alleles for another gene (only true for genes on different chromosomes, or far away on the same chromosome)

Question 28

monohybrid cross

Answer 28

a breeding experiment for an organism that differs in one trait

Question 29

dihybrid cross

Answer 29

a breeding experiment for an organism that differs in two traits

Question 30

monohybrids

Answer 30

individuals heterozygous for one trait

Question 31

dihybrids

Answer 31

individuals heterozygous for two traits

Question 32

complete dominance

Answer 32

one allele is completely dominant over the other; heterozygous phenotype is the same as homozygous dominant; ex: red and white gives red

Question 33

incomplete dominance

Answer 33

heterozygous phenotype is intermediate; ex: red and white gives pink

Question 34

codominance

Answer 34

both phenotypes are expressed in a heterozygote; ex: A and B give AB

Question 35

multiple alleles

Answer 35

in the whole population some genes have more than two alleles; ex: A, B, O

Question 36

pleiotropy

Answer 36

one gene is able to affect multiple phenotypic characters; ex: sickle-cell disease

Question 37

epistasis

Answer 37

the phenotypic expression of one gene affects that of another; ex: baldness and hair color; yellow labs

Question 38

polygenic inheritance

Answer 38

a single phenotypic character is affected by two or more genes; ex: eye color, skin color

Question 39

norm of reaction

Answer 39

the phenotypic range of a particular genotype (the phenotype can be influenced by the environment)

Question 40

multifactorial characters

Answer 40

polygenic characters that are also influenced by the environment; ex: skin color and tanning

Question 41

carriers

Answer 41

heterozygotes that carry a recessive gene (for some disorder)