week 7

Question 1

zygote

Answer 1

2 parent gametes that fertilize to form diploid cells or zygotes

Question 2

cell cycle

Answer 2

a highly regulated series of events that lead to cell division (when cells are ready to divide they become compact)

Question 3

cytogenetics

Answer 3

field of genetics involving microscopic examination of chromsomes

Question 4

karyotype

Answer 4

a photographic representation of chromosomes

Question 5

homologous chromosomes

Answer 5

in diploid species, members of a pair of chromosomes

Question 6

eukaryotic chromosomes

Answer 6

occur in sets
on set has 23 chromosomes
22 autosomes
humans have 2 sets 46 total

Question 7

two chromosome sets

Answer 7

diploid or 2n

Question 8

gamete

Answer 8

sperm and eggs have only 1 set of chromosomes = haploid or n

Question 9

interphase

Answer 9

g1
s phase
g2
m

Question 10

G1

Answer 10

(11 hours)
first gap
accumulates molecular changes that promote progression through cell cycle

Question 11

s phase

Answer 11

(8 hours)
chromosome replication produces 6 pairs of sister chromatids

Question 12

G2

Answer 12

(4 hours)
nucleus breaks apart, and replicated chromosomes condense in preparation for mitosis
some growth may occur

Question 13

M phase

Answer 13

(1hour)
sister chromatids separate during mitosis, and 2 cells are formed during cytokinesis (2 daughter cells containing 6 chromosomes each)

Question 14

3 critical checkpoints

Answer 14

g1, g2, metaphase

Question 15

mitotic cell division

Answer 15

cells divide to produce two new cells (daughter cells) genetically identical to the original (mother cell)

Question 16

the spindle apparatus

Answer 16

a structure composed of microtubules, responsible for organizing and sorting the chromosomes

Question 17

mitosis

Answer 17

making 2 daughter cells from 1 original cell

Question 18

Mitosis pneumonic (stages in order)

Answer 18

PPMAT

prophase
prometaphase
metaphase
anaphase
telophase
cytokinesis

Question 19

prophase

Answer 19

chromatids condense into highly compacted structures that are readily visible by microscope
- nuclear membrane begins to dissolve into small vesicles, nucleolus no longer visible

Question 20

prometaphase

Answer 20

nuclear envelop completely fragments and spindle apparatus is fully formed
sister chromatids become attached to kinetochore microtubules from opposite poles

Question 21

metaphase

Answer 21

Characterised by pairs of sister chromatids aligned in a single row along a plane halfway between the poles called the metaphase plate

Question 22

anaphase

Answer 22

connections between sister chromatids are broken & kinetochore microtubules shorten, pulling chromosomes toward the pole to which

Question 23

telophase

Answer 23

chromosomes reach their respective poles and decondense
nuclear membranes re-form to produce two separate nuclei

Question 24

cytokinesis

Answer 24

happens quickly after mitosis
animals- cleavage furrow constricts like a drawstring to separate the cells
plants - vesicle from the Golgi apparatus from a cell plate, which forms a cell wall between the two daughter cells

Question 25

end result of mitosis

Answer 25

two daughter cells with the same number of chromosomes as the mother cell
barring mutations, two daughter cells are identical

Question 26

meiosis

Answer 26

takes cell chromosome number and reduces it to half (diploid->haploid)

Question 27

meiosis 1 key events

Answer 27

1. homologous pairs of chromosome segments form bivalent in the process of synapsis
2. crossing over results in physical exchange between chromosome segments from the bivalent

Question 28

steps of meiosis I

Answer 28

prophase I
pro metaphase I
metaphase I
anaphase I
telophase I
cytokinesis

Question 29

meiosis I results in…

Answer 29

2 haploid cells with no pairs of homologous chromosomes

Question 30

prophase I

Answer 30

replicated chromosomes condense, bivalents form, and the nuclear membrane starts to fragment

Question 31

pro metaphase I

Answer 31

spindle apparatus is formed, and kinetechore microtubules attached to sister chromatids

Question 32

metaphase I

Answer 32

bivalents are organized along metaphase plate as a double row

Question 33

anaphase I

Answer 33

segregation of homologs occur
connections between bivalents break, but sister chromatids stay connected together
each joined pair of chromatids migrates to one pole, while homologous pair moves to the opposite pole

Question 34

Telophase I

Answer 34

sister chromatids have reached their respective poles and decondense; nuclear membranes reform producing two separate nuclei

Question 35

meiosis II

Answer 35

separates sister chromatids
DNA is not replicated between meiosis I and II
sorting events of MII are similar to those of mitosis but starting point is different

Question 36

mitosis - meiosis I - meiosis II

Answer 36

two diploid daughter cells - 2 haploid cells - 4. haploid daughter cells