Cell Cycle

Question 1

homologs

Answer 1

members of a homologous chromosomal pair

Question 2

reductional division

Answer 2

reduction of ploidy (2n -> n) during separation of homologs in meiosis 1

Question 3

equational division

Answer 3

separation of sister chromatids during meiosis 2 (analogous to mitosis), no reduction in ploidy (n -> n)

Question 4

chromosome

Answer 4

strand of DNA encoded with genes

Question 5

chromatid

Answer 5

1 of 2 identical halves of a replicated chromosomes (joined to sister at centromere)

Question 6

meiosis

Answer 6

2 rounds of cellular division to generate haploid products and genetic diversity

Question 7

mitosis

Answer 7

cell division to create 2 identical daughter cells

Question 8

non-disjunction

Answer 8

unequal separation of homologs or sister chromatids during cell division

Question 9

independent assortment

Answer 9

random assortment of homologous chr. into daughter cells during anaphase 1 to generate genetic diversity

Question 10

separation of homologs

Answer 10

generation of haploid cells in meiosis 1

Question 11

separation of chromatids

Answer 11

generation of identical daughter cells in meiosis 2

Question 12

autosomes

Answer 12

any numbered chromosome (22) except sex chromosomes

Question 13

sex chromosomes

Answer 13

chromosome that determines sex of organism (23)

Question 14

diploid

Answer 14

homologous pair of every chromosome (2n)

Question 15

crossing over

Answer 15

physical exchange of DNA between non-sister chromatids of homologs during prophase 1 (aka. chiasmata)

Question 16

haploid

Answer 16

single set of unpaired chromosomes in gametes (n)

Question 17

fertilization

Answer 17

creation of a diploid cell/zygote by fusion of maternal and paternal haploid gametes

Question 18

n-value

Answer 18

number of chromosomes found in a haploid cell (n), does not change in mitosis or equational division, halves in meiosis 1

Question 19

c-value

Answer 19

amount of DNA in bps, changes throughout cell cycle (doubles in S phase) and halves in meiosis (start to finish)

Question 20

centromere

Answer 20

point of association btwn sister chromatids

Question 21

karyotype

Answer 21

picture of all chromosomes

Question 22

heterogametic

Answer 22

XY sex (X or Y gamete, determines sex of offspring)

Question 23

homogametic

Answer 23

XX sex (only X gametes)

Question 24

p arm

Answer 24

short arm of acrocentric chr

Question 25

q arm

Answer 25

long arm of acrocentric chr

Question 26

metacentric

Answer 26

centromere in middle of chr

Question 27

telocentric

Answer 27

centromere right at end of chr (none in humans, unstable)

Question 28

acrocentric

Answer 28

centromere is asymmetrically placed

Question 29

allostery

Answer 29

binding of a molecule to a protein other than the active site changes the conformation or activity of that protein

Question 30

genotype

Answer 30

all of an organism's genes and DNA, description of all alleles present

Question 31

phenotype

Answer 31

physical manifestation of genotype

Question 32

haploid

Answer 32

1 copy of every chr

Question 33

diploid

Answer 33

2 copies of every chr

Question 34

heterozygote

Answer 34

an organism w/ diff alleles at gene of interest

Question 35

homozygote

Answer 35

an organism w/ identical alleles at gene of interest

Question 36

hemizygote

Answer 36

an organism that naturally has only 1 copy of a gene despite being diploid (XY male: all genes on X chr)

Question 37

gene

Answer 37

a region of a chr that is transcribed and influences heredity

Question 38

allele

Answer 38

a variant of a gene

Question 39

dominant

Answer 39

allele is fully expressed when 1 copy is present

Question 40

recessive

Answer 40

allele is not expressed when 1 copy is present (must have 2 alleles)

Question 41

haplosufficient

Answer 41

1 copy of WT allele is sufficient for normal phenotype (mutant allele is recessive)

Question 42

haploinsufficient

Answer 42

1 copy of WT allele is insufficient for normal phenotype (mutant allele is dominant)

Question 43

homologous

Answer 43

chromosomes share same gene order, not necessarily same alleles (A;a)

Question 44

non-homologous

Answer 44

do not have the same genes and dont pair in meiosis

Question 45

monohybrid cross

Answer 45

a cross btwn 2 individuals identically heterozygous at one gene pair (Aa x Aa)

Question 46

true-breeding

Answer 46

a group of identical individual organisms that always produce offspring of the same phenotype (AA or aa ie. are homozygous)

Question 47

dihybrid cross

Answer 47

a cross btwn 2 individuals identicall heterozygous at 2 loci (AaBb x AaBb)

Question 48

testcross

Answer 48

cross of an organism with an unknown genotype to a tester

Question 49

parental cross

Answer 49

homozygous dominant x homozygous recessive

Question 50

why is a monohybrid cross performed?

Answer 50

to test dominance

Question 51

tester

Answer 51

organism homozygous recessive for all alleles being tested

Question 52

what ratio would a het vs homozygous give when crossed w/ a tester?

Answer 52

``` het = 1 : 1 hom = 1 : 0 ```

Question 53

why is a test cross performed? (2)

Answer 53

determine genotype of an unknown individual, test linkage

Question 54

when is a dihybrid cross performed?

Answer 54

to determine how genes interact

Question 55

what ratio does a monohybrid cross give?

Answer 55

3 : 1

Question 56

what ratio does a dihybrid cross give?

Answer 56

9 : 3 : 3 : 1

Question 57

reciprocal cross

Answer 57

swap sexes of parental to determine if a gene is on an X chr (sex-linked)

Question 58

auxotroph

Answer 58

organisms that cannot grow on MM (contains mutation in biochemical pathway for essential nutrients)

Question 59

prototroph

Answer 59

organism that can grow on MM ("WT")

Question 60

minimal media (MM)

Answer 60

basic components required for WT growth

Question 61

wildtype

Answer 61

commonly accepted normal for a lab organism

Question 62

mutant

Answer 62

permanent alteration in DNA of a gene that differs from WT

Question 63

complementation

Answer 63

production of a WT phenotype when 2 diff recessive mutations are combined in a diploid or heterokaryon (fusion of 2 haploid cells, 2 nuclei)

Question 64

non-allelic

Answer 64

2 mutants of diff gene (dont form complementation group)

Question 65

allelic

Answer 65

a complementation group btwn 2 mutants of the same gene