Luther Prep Biology Chapter 06

Front 1

allele

Back 1

any of the alternative forms of a gene that occurs at a specific place on a chromosome

Front 2

autosome

Back 2

chromosome that contains genes for characteristics not directly related to the sex of the organism

Front 3

cross

Back 3

mating of two organisms

Front 4

crossing over

Back 4

exchange of chromosome segments between homologous chromosomes during meiosis I

Front 5

dihybrid cross

Back 5

cross, or mating, between organisms involving two pairs of contrasting traits

Front 6

diploid

Back 6

cell that has two copies of each chromosome, one from an egg and one from a sperm

Front 7

dominant

Back 7

allele that is expressed when two different alleles are present in an organism's genotype

Front 8

egg

Back 8

female gamete

Front 9

fertilization

Back 9

fusion of an egg and sperm cell

Front 10

gamete

Back 10

sex cell; an egg or a sperm cell

Front 11

gametogenesis

Back 11

process by which gametes are produced through the combination of meiosis and other maturational changes

Front 12

gene

Back 12

specific region of DNA that codes for a particular protein

Front 13

genetic linkage

Back 13

tendency for genes located close together on the same chromosome to be inherited together

Front 14

genetics

Back 14

study of the heredity patterns and variation of organisms

Front 15

genome

Back 15

all of a organism's genetic material

Front 16

genotype

Back 16

collection of all an organism's genetic information that codes for traits

Front 17

haploid

Back 17

cell that has only one copy of each chromosome

Front 18

heterozygous

Back 18

characteristics of having two different alleles that appear at the same locus of sister chromatids

Front 19

homologous chromosome

Back 19

chromosomes that have the same length, appearance, and copies of genes, although the alleles may differ

Front 20

homozygous

Back 20

characteristics of having two of the same alleles at the same locos of sister chromatids

Front 21

law of independent assortment

Back 21

Mendel's second law, stating that allele pairs separate from one another during gamete formation

Front 22

law of segregation

Back 22

Mendels first law, stating that (1) organisms inherit two copies of genes, one from each parent, and (2) organisms donate only one copy of each gene i their gametes because the genes separate during gamete formation

Front 23

meiosis

Back 23

form of nuclear division that divides a diploid cell into haploid cells; important in forming gametes for sexual reproduction

Front 24

monohybrid cross

Back 24

cross, or mating, between organisms that involves only one pair of contrasting traits

Front 25

phenotype

Back 25

collection of all of an organism's physical characteristics

Front 26

polar body

Back 26

haploid cell produced burring meiosis in the female of many species; these cells have little more than DNA and eventually disintegrate

Front 27

probability

Back 27

likelihood that a particular event will happen

Front 28

Punnett Square

Back 28

model for predicting all possible genotypes resulting from a cross, or mating

Front 29

purebred

Back 29

type of organism whose ancestors are genetically uniform

Front 30

recessive

Back 30

allele that is not expressed unless two copies are present in an organism's genotype

Front 31

sex chromosome

Back 31

chromosome that directly controls the development to sexual characteristics

Front 32

sexual reproduction

Back 32

process by which two gametes fuse and offspring that are a genetic mixture of both parents are produced

Front 33

somatic cell

Back 33

cell that makes up all of the body tissues and organs, except gametes

Front 34

sperm

Back 34

male gamete

Front 35

testcross

Back 35

cross between an organisms with an unknown genotype and an organisms with a recessive phenotype

Front 36

trait

Back 36

characteristic that is inherited