Chapter 10 Exam 3

Question 1

what are microtubules made of

Answer 1

tubulin

Question 2

what are microfilaments made of

Answer 2

actin

Question 3

what makes up a tubulin dimer

Answer 3

alpha tubulin and beta tubulin

Question 4

where are the minus ends positioned in microtubules

Answer 4

at the organizing center of the centrosome

Question 5

what is dynamic instability

Answer 5

cycles of polymerization and depolymerization in microtubules

Question 6

what is microtubule catastrophe

Answer 6

dramatic shrinkage because the plus end of a microtubule is structurally unstable

Question 7

what transport protein moves on microfilaments

Answer 7

myosin

Question 8

what direction does myosin move

Answer 8

minus to plus end

Question 9

what transport proteins move on microtubules

Answer 9

kinesin and dynein

Question 10

what direction does kinesis move

Answer 10

minus to plus end

Question 11

what direction does dynein move

Answer 11

plus to minus end

Question 12

how does binary fission occur

Answer 12

1. DNA is attached to inner membrane by proteins
2. DNA replication begins bidirectionally around the circle
3. new Dna is attached to inner membrnae
4. the cell elongates around the midpoint separating the DNA attachment sites
5. synthesis of new membranes and wall material at midpoint
6. synthesis completes and constriction separates the daughter cells

Question 13

when does binary fission occur

Answer 13

in prokaryotes

Question 14

what does meiosis lead to

Answer 14

4 daughter cells having half the amount of genetic material as the parent cell

Question 15

what does mitosis lead to

Answer 15

daughter cells are genetically identical to the parent cell

Question 16

what does interphase consist of

Answer 16

G1 phase, S phase, G2 phase

Question 17

what happens in G1

Answer 17

gap phase, size and protein content increases

Question 18

what happens in S phase

Answer 18

DNA is replicated

Question 19

what happens in the G2 phase

Answer 19

lag prior to mitosis and cytokinesis

Question 20

what happens in M phase

Answer 20

mitosis and cytokinesis

Question 21

what happens in G0 phase

Answer 21

nothing

Question 22

what are homologous chromosomes

Answer 22

carry the same set of genes, one from the mother and one from the father

Question 23

what are the 5 stages of mitosis

Answer 23

prophase, prometaphase, metaphase, anaphase, telophase

Question 24

what happens in prophase

Answer 24

chromosomes condense. centrosomes radiate microtubules and migrate to opposite poles

Question 25

what happens in prometaphase

Answer 25

microtubules of the mitotic spindle attach to chromosomes

Question 26

what happens in metaphase

Answer 26

chromosomes are lined up in a single plane roughly equidistant from both of the spindle poles

Question 27

what happens in anaphase

Answer 27

sister chromatids separate and travel to opposite poles

Question 28

what happens in telophase

Answer 28

nuclear envolepr forms and chromosomes decondense

Question 29

what do kinetochores do

Answer 29

forms the site of attachment for a single microtubule

Question 30

what is cytokinesis

Answer 30

plants must construct a new cell wall

Question 31

what happens in cytokinesis

Answer 31

during telophase the plant cells form a structure called the phragmoplast that consists of microtubules that guide vesicles containing cell wall components to the middle of the cell

Question 32

what do the vesicles in cytokinesis do

Answer 32

fuse to form a new cell wall called the cell plate in the middle of the dividing cell

Question 33

what happens in prophase 1 of meiosis 1

Answer 33

DNA replication is complete, homologous chromosomes condense and undergo synapsis, the homologous chromosomes form a bivalent, the chiasmata forms. the nuclear envelope breaks down

Question 34

what is chiasmata

Answer 34

crossing over

Question 35

what happens in prophase 2 Meiosis 2

Answer 35

the nuclear envelope breaks down and chromosomes condense

Question 36

what happens in metaphase 2 meiosis 2

Answer 36

chromosomes align in center of the cell

Question 37

what happens in anaphase 2

Answer 37

sister chromatids separate

Question 38

what happens in telophase 2

Answer 38

the nuclear envelope reforms

Question 39

what does cyclin do

Answer 39

activate the enzymes (CDKs) that promote cell divsion

Question 40

what are the 3 types of cylcins

Answer 40

G1/S cyclin, S cyclin, M cyclin

Question 41

what does G1/S cyclin do

Answer 41

prepares cell for DNA replication

Question 42

what does S cyclin do

Answer 42

helps initiate DNA synthesis

Question 43

what does M cyclin do

Answer 43

helps prepare the cell for mitosis

Question 44

what happens at the DNA replication checkpoint

Answer 44

checks for the presence of unreplicated DNA at the end of G2 before cell enters mitosis

Question 45

what happens at the DNA damage checkpoint

Answer 45

checks for damaged DNA before it enters S phase

Question 46

what happens at the spindle assembly checkpoint

Answer 46

checks for all chromosomes being attached to the spindle before the cell progresses with mitosis

Question 47

what is the role of p53 in the DNA damage checkpoint

Answer 47

it keeps the cell from replicating if there is DNA damage, it is phosphorylated and accumulates in the nucleus and activates genes that halt replication and turns on repair mechanisms to fix DNA

Question 48

what is an Onco gene

Answer 48

cancer causing gene

Question 49

what is a proton Onco gene

Answer 49

normal genes important in cell division can be cancerous if mutated

Question 50

what do tumor suppressors do

Answer 50

encode proteins whose normal activities inhibit cell division