Unit 5 Genetics

Question 1

fertilization

Answer 1

combines two haploid gamete cells into a new zygote

Question 2

meiosis

Answer 2

reduces diploid cells back to haploid gametes so DNA can be combined into next generation of organisms

Question 3

meiosis 1st division

Answer 3

homologs seperate, reductional division where 4c reduces to 2c, crossing over takes place

Question 4

meiosis 2nd division

Answer 4

sister chromatids seperate, equational division

Question 5

ploidy

Answer 5

genetic content (n) or number of chromosome copies (c)

Question 6

reductionol division

Answer 6

decreases the genetic content

Question 7

equational division

Answer 7

separates sister chromatids

Question 8

crossing over

Answer 8

in prophase I, parts of each sister chromatid swap places to increase genetic variation

Question 9

interkenisis

Answer 9

cell rests, reestablishes energy stores and organizes chromosomes, no DNA replication

Question 10

prophase 2

Answer 10

spindle fibers drag chromosomes to center of cell

Question 11

metaphase 2

Answer 11

duplicated sister chromatids are separated

Question 12

anaphase 2

Answer 12

full separation of sister chromatids

Question 13

segregation

Answer 13

maternal and paternal alleles for a gene are segregated into different gametes

Question 14

why is genetic variation important?

Answer 14

to face changing environmental conditions

Question 15

independent assortment

Answer 15

different genes for different traits are inherited independently of one another (unless they are located close to each other on the same chromosome)

Question 16

synapsis

Answer 16

as homologous chromosomes are condensed and collected they are temporarily bound by synaptimal complex

Question 17

law of dominance

Answer 17

certain alleles can mask the presence of others

Question 18

law of segregation

Answer 18

parental genes are randomly separated, offspring inherit one genetic allele from each parent

Question 19

law of independent assortment

Answer 19

alleles for different genes are inherited independently from one another (exception is linked genes)

Question 20

punnet square

Answer 20

table used to predict outcome of a genetic cross

Question 21

genetypic ratio

Answer 21

alleles ratios (ex: PP-1 Pp-2 pp-1)

Question 22

phenotypic ratio

Answer 22

characteristic ratio (ex: 3 purple flowers, 1 white)

Question 23

genotype

Answer 23

combination of letters, genetic makeup

Question 24

phenotype

Answer 24

the way the trait appears, physical characteristic

Question 25

addition rule

Answer 25

add or subtract the probability of one event happening over the other (either/or)

Question 26

multiplication rule

Answer 26

multiply probability of two events to calculate the probability of them happening at the same time

Question 27

mitochondrial dna

Answer 27

from mother only

Question 28

nonmendalian genetics

Answer 28

study of traits and genes that are not inherited in line of mendel's law

Question 29

incomplete dominance

Answer 29

when a heterozygote for a particular trait is a mix of homozygous phenotypes (hybrid doesn't resemble either parent, ex: red and white flower produce pink)

Question 30

codominant traits

Answer 30

heterozygote shows both phenotypes (ex: AB blood type)

Question 31

linked genes

Answer 31

when two genes are not inherited independently because they are located on the same chromosome

Question 32

polygenic traits

Answer 32

traits controlled by more than one gene (ex: skin color)

Question 33

pleiotropy

Answer 33

when one gene controls multiple, seemingly unrelated traits

Question 34

lethal allele

Answer 34

an allele that causes death when inherited

Question 35

sex-linked traits

Answer 35

traits related to genes on sex chromosomes

Question 36

nonnuclear inheritance

Answer 36

DNA found in chloroplast and mitrochondria

Question 37

recombinant frequency

Answer 37

recominants/total offspring x 100 = RF

Question 38

environmental affects on phenotype

Answer 38

food/nutrients, soil pH (phenotypic plasticity with hydrengaes)

Question 39

phenotypic plasticity

Answer 39

signals in the environment that change gene expression, environmentally driven variations have evolutionary advantage

Question 40

fruit fly experiments

Answer 40

discovered recessive problems on X chromosomes with fly's eye color

Question 41

heredity

Answer 41

transmission of traits from one generation to the next

Question 42

somatic cells

Answer 42

all cells in the body minus reproductive cells

Question 43

locus

Answer 43

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

Question 44

asexual reproduction

Answer 44

single individual is the sole parent, passes identical DNA to offspring and gives rise to clone

Question 45

karyotype

Answer 45

ordered display of chromosomes by length

Question 46

autosomes

Answer 46

chromosomes that aren't sex chromosomes

Question 47

diploid cell

Answer 47

cell with two chromosome sets (maternal and paternal) 2n

Question 48

homologous chromosomes

Answer 48

2 chromosomes of a pair with the same length, staining pattern, and centromere position

Question 49

chiasma

Answer 49

hold homologs together as spindle fibers for the 1st meiototic division

Question 50

hybridization

Answer 50

crossing of two true breeding varieties (creating hybrids)

Question 51

test cross

Answer 51

breeding an organism of unknown genotype with a homozygous recessive to reveal organism's genotype