chapter twelve/thirteen

Question 1

regulatory molecules of mitosis

Answer 1

protein kinases and cyclins

Question 2

checkpoints of mitosis

Answer 2

1. G1
2. M
3. metaphase/anaphase

Question 3

G1 checkpoint

Answer 3

restriction point, allows completion of G1, S, G2, M, and division phases

Question 4

M checkpoint

Answer 4

between G2/M, checks for damaged/unreplicated DNA

Question 5

metaphase/anaphase checkpoint

Answer 5

checks spindle attachment and tension

Question 6

protein kinases

Answer 6

activate/inactivate other proteins by phsophorylating them

Question 7

cyclins

Answer 7

protein that has cyclic fluctuating concentration in the cell
- attaches to kinase, cyclin-dependent kinases

Question 8

G0 phase

Answer 8

non dividing state, if G1 checkpoint doesn’t receive “go-ahead” signal

Question 9

external regulators of mitosis

Answer 9

growth factors, mitogen

Question 10

growth factors

Answer 10

1. epidermal
2. fibroblast
3. platelet-derived

Question 11

growth factors

Answer 11

protein released by certain cells that stimulate other cells to divide

Question 12

PDGF

Answer 12

required for division of cultured fibroblasts to heal wound, made by platelets

Question 13

mitogen

Answer 13

small protein that induces cell to begin or enhance rate of division

Question 14

cancer cells…

Answer 14

divide indefinitely/excessively, don’t depend on growth factors/normal signals

Question 15

transformation

Answer 15

conversion of cells in culture to divide like cancer cells
- give new characteristics

Question 16

tumor

Answer 16

mass of abnormal cells within otherwise normal tissue

Question 17

benign

Answer 17

tumor that remains at original site if their genetic/cellular changes don’t allow them to move or survive at another site

Question 18

malignant

Answer 18

tumor that becomes transformed, spreads to new tissues and impairs function of 1+ organs, near capillaries for nutrition and spread

Question 19

metastasis

Answer 19

spread of cancer cells to locations distant from the original site
- enter blood/lymph vessels and travel throughout body

Question 20

heredity

Answer 20

transmission of traits from one generation to the next

Question 21

variation

Answer 21

no multicellular organisms completely identical (most of time)

Question 22

genetics

Answer 22

study of both heredity and inherited variation

Question 23

genes

Answer 23

hereditary units (coded information)

Question 24

DNA

Answer 24

polymer of 4 dif nucleotides that contains genetic program

Question 25

locus

Answer 25

gene's specific location along the length of a chromosome

Question 26

asexual reproduction

Answer 26

single individual is sole parent and passes copies of all its genes to offspring w/o fusion of gametes - creates clones - differences come from mutations

Question 27

sexual reproduction

Answer 27

2 parents produce offspring w/ unique combinations of genes inherited from parents - 2 gametes - variation

Question 28

karyotype

Answer 28

display of chromosome pairs of a cell arranged by size/shape

Question 29

homologous chromosomes

Answer 29

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

Question 30

sex chromosomes

Answer 30

X/Y chromosomes that determine sex - female - XX (homologous) - male - XY (heterologous)

Question 31

autosomes

Answer 31

chromosomes that aren't sex chromosomes

Question 32

somatic cells (diploid)

Answer 32

- 2 sets of 23 chromosomes (2n=46) - even when DNA duplicated, cell still considered diploid - 44 autosomes, 2 sex chromosomes

Question 33

gametes (haploid)

Answer 33

- 23 chromosomes (n) - transmit genes down generations - 22 autosomes, 1 sex chromosome

Question 34

fertilization (zygotę)

Answer 34

resulting fertilized egg (diploid) - union of gametes culminating in fusion of nuclei

Question 35

where do gametes develop from

Answer 35

germ cells in gonads

Question 36

meoisis

Answer 36

cell division that reduces number of sets of chromosomes from 2 in parent cell to 1 in each gamete

Question 37

sexual life cycle

Answer 37

n to fertilization to 2n (mitosis/development) to meiosis to n

Question 38

tetrads

Answer 38

2 homologous chromsomes in synpasis

Question 39

what do you have at the end of meiosis 1

Answer 39

haploid number of chromosomes

Question 40

why does meiosis 2 occur

Answer 40

to get the right amount of DNA

Question 41

prophase I

Answer 41

- synapsis, crossing over, synaptonemal complex, tetrad, chiasma - spindle fibers form - chromosomes condense - nucleolus disappears - centrosome movement

Question 42

synapsis

Answer 42

2 homologs joined together by synaptonemal complex

Question 43

crossing over

Answer 43

each chromosome pairs w/ homolog, DNA molecules of NONSISTER chromatids are broken by proteins + rejoined to each other

Question 44

synaptonemal complex

Answer 44

zipper-like protein complex that attaches 1 homolog to the other, includes enzymes for crossovers

Question 45

metaphase I

Answer 45

alignment of homologous chromosomes (tetrads) on metaphase plate - 46 chromosomes - 23 tetrads - 92 sister chromatids

Question 46

chiasma

Answer 46

X-shaped region in homologous pair where crossovers have occured

Question 47

anaphase I

Answer 47

breakdown of proteins responsible for sister chromatid cohesion, homologs separate and move to opposite poles - 92 chromatids

Question 48

telophase I/cytokinesis

Answer 48

each resulting cell has complete haploid set of duplicated chromsomes

Question 49

what does not occur between meiosis I and II?

Answer 49

DNA replication

Question 50

second meiotic division

Answer 50

1. prophase II 2. metaphase II 3. anaphase II 4. telophase II/cytokinesis

Question 51

mitosis overview

Answer 51

- identical cells/chromosomes - genetic constancy - variation by mutation - 2N -> 2N - somatic cells - 2 cells produced - 1 division sequence

Question 52

meiosis overview

Answer 52

- different cells/chromosomes - genetic variety - vacation by mutation/recomb - 2N -> N - gametes - 4 cells produced - 2 division sequences

Question 53

what leads to genetic variation in gametes?

Answer 53

independent assortment, crossing over, which sperm fertilizes which egg

Question 54

independent assortment of chromosomes

Answer 54

- random orientation of pairs of homologous/ind chromosomes - metaphase I

Question 55

recombinant chromosomes

Answer 55

- crossing over (1-3 crossovers per pair) - ind chromosomes that carry genes from 2 dif parents

Question 56

how many different diploid combinations are there?

Answer 56

70 trillion