BSC 114 Exam 3

somatic cells have __ chromosomes

somatic cells have __ chromosomes

46

chromatin is found in the

nucleus

reproductive cells have __ chromosomes

23

reproductive cells

germ cells

cells total hereditary endowment of DNA

genome

DNA is complexed with proteins called

histones

__ forms chromosomes

chromatin

length of cell cycle varies from

10-30 hours

G1

growth

S

replication

G2

preparation for division

function of mitosis

separate genetic info into 2 quantities

organize microtubules of spindle apparatus

centrosomes

region where chromatids are held together

centromere

protein structure on chromatids where spindle microtubules attach

kinetochore

kinetochore is located at the __ region

centromere

interphase has __ nucleus

1

interphase has __ chromosomes, each consisting of __ chromatid(s)

46, 1

prophase has __ nucleus

1

prophase has __ chromosomes, each consisting of __ chromatid(s)

46, 2

telophase has __ nucleus

2

t/f: cell cycle includes both interphase and mitosis

true

t/f: interphase is much longer and complicated than mitosis

true

__ phase of cell cycle is the key phase in controlling cell division

G1

determines whether cell divides

restriction point of G1

stimulates other cells to divide

growth factor

says that crowded cells usually stop dividing

density dependent inhibition

a single individual is the sole parent and passes on all of its genes directly to its offspring

asexual reproduction

group of genetically identical individuals

clone

t/f: no multicellular organisms can reproduce asexually

false, some can

the only possible differences between the parent and offspring will be via __

mutations

much greater genetic variation results from __ reproduction compared to __ reproduction

sexual, asexual

karyotype organizes chromosomes according to

number, size, type

chromosomes in karyotype are arrested in the __ stage of mitosis

metaphase

chromosomes that look quite similar but were inherited from different parents

homologous chromosomes

in __ organisms, chromosomes are matched in homologous pairs

diploid

specific location of a gene

locus

homologs differ in the version of some genes at their corresponding __

loci

X and Y

sex chromosomes

non sex chromosomes

autosomes

cell with a single set of chromosomes

haploid

cell containing 2 sets of chromosomes, one from each parent

diploid

process that halves the diploid set to a single haploid set of chromosomes

meiosis

restores the diploid set from meiosis

fertilization

meiosis II results in __ daughter cells instead of 2 and each has only __ the number of chromosomes

4, half

arrangement of chromosomes on the __ plate determines which chromosomes will be packaged together

metaphase I

a point at which paired chromosomes remain in contact during metaphase I of meiosis, and at which crossing over and exchange of genetic material occur.

chiasmata

crossing over occurs during __ of meiosis I

prophase

__ produces individual chromosomes that combine genes inherited from our 2 parents

crossing over

when homologous portions of 2 non sister chromatids trade places

recombination

humans have - crossovers per pair of chromosomes

2-3

yellow, purple, round

dominant

green, white, wrinkled

recessive

each gamete has __ allele(s)

1

members of a pair of genes separate from each other during gamete formation

law of segregation

each character an organism inherits __ allele(s)

2

alternate versions of genes

alleles

genetic composition

genotype

outward appearance

phenotype

cross involving genes at 1 locus

monohybrid cross

to determine genotype of a parent with a dominant phenotype, a __ can be done on unknown genotype

test cross

tester

homozygous recessive

mendel's second law

law of independent assortment

says that genes for a pair of traits are distributed independently of one another when gametes are formed

law of independent assortment

law of independent assortment only occurs when the genes are

on separate chromosomes

examines the inheritance of genes at __ loci

2

dominant allele codes for

functional protein

recessive allele codes for

nonfunctional protein

__ dominance says that YY and Yy have the same phenotype

complete

__ dominance says that both alleles are expressed. ex: AB blood

co

__ dominance says that the phenotype is intermediate between homozygous phenotypes

incomplete

an individual can only have __ alleles per locus

2

t/f: an individual can only have 2 alleles per locus, but there can be more than 2 in the population

true

blood groups are examples of (2)

multiple alleles and codominance

t/f: each sperm and egg can have multiple alleles

false; only 1

gene interaction

epistasis

a gene at one location may affect more than one trait

pleiotropy

multiple genes affect one trait

polygenic inheritance

phenotype is the results of interaction between

genotype and environment

males designated with __

squares

females designated with __

circles

trait being traced is designated with __

shaded area

a death is designated with __

slashed area

chromosomes occur in __ nuclei

2n

chromosomes separate at __

meiosis

t/f: chromosomes exhibit independent assortment

true

chromosomes unite at __

fertilization

a cell contains __ genes

thousands

t/f: all genes follow independent assortment

false, lots of genes on the same chromosome

genes that are close together on the same chromosome

linked

linked chromosomes do not exhibit independent assortment during __

meiosis

on different chromosomes, independent assortment

unlinked genes

first to associate a specific gene with a specific chromosome

Thomas Hunt Morgan

gene takes its symbol from the first __ discovered

mutant

normal phenotype is called

wild type

offspring like parents

parentals

offspring different from the parents

recombinants

independent assortment results

50 parental, 50 recombinant

linked and no crossing over results

100 parental

linked and crossing over results

depends on frequency of crossing over