Chapter 10 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What type of cell division occurs in bacteria?

A

Binary fission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Ploidy

A

the number of set of chromosomes an organisms has

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Haploid (n)

A

one complete set of chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Diploid (2n)

A

total number of chromosomes in a cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How many chromosomes in a haploid cell?

A

23

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How many chromosomes in a diploid cell?

A

46

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Homologous

A

a pair of the same kind of chromosome in a diploid cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Homologue

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Karyotype

A

particular array of chromosomes an organism possesses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are chromosomes composed of?

A

Chromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Heterochromatin

A

Inactive domains of chromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Euchromatin

A

active domains of chromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Nucleosome

A

complex consisting of a DNA duplex would around a core of eight histone proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the nucleosome composed of?

A

DNA and histone proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Histone proteins have a ______ charge, which are strongly attracted to _______ charged DNA

A

+, -

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are four histones contained in nucleosomes?

A

H2A, H2B, H3, H4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The primary histones (H2A, H2B, H3, H4) associate together to form a _________________.

A

histone octamer complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Condensin and cohesin are both examples of

A

SMC proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cohesin

A

protein complex that holds sister chromatids together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Condensation/decondensation

A

How tightly chromosomes are wound depends of the phase of the cell cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why would chromosomes be decondensed?

A

To express genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why would chromosomes be condensed?

A

to separate during cell division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Condensation is controlled by the protein _____.

A

condensin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Sister chromatids

A

Two replicas of a single chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the five phases of the cell cycle?

A

G1, S, G2, M, cytokinesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

G1 (gas phase 1)

A

primary growth phase of cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

S (synthesis)

A

genome is duplicated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

G2 (gap phase 2)

A

organelles replicate, microtubules organize

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Mitosis

A

spindle apparatus assembles, bind to chromosomes, and moves sister chromatids apart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the five phases of mitosis?

A
  1. Prophase
  2. Prometaphase
  3. Metaphase
  4. Anaphase
  5. Telophase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Cytokinesis

A

cytoplasm divides, creating two daughter cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Mitosis and cytokinesis make up the __________

A

M phase

33
Q

_______ and ________ make up the M phase

A

Mitosis; cytokinesis

34
Q

How long is the cell cycle in typical mammal cells?

A

24 hours

35
Q

How long is the cell cycle in human embryos?

A

20 minutes

36
Q

How long is the cell cycle in human liver cells?

A

More than a year

37
Q

What types of cells remain in G0 phase permanently?

A

Muscle and nerve cells

38
Q

What occurs in S (synthesis) phase?

A
  • Cell’s DNA is replicated
  • Each chromosomes replicates to produce two sister chromatids
39
Q

Cohesion proteins

A

hold centromeres of two sister chromatids together

40
Q

Where do microtubules attach?

A

Kinetochore

41
Q

What occurs during G2 phase?

A
  • chromosomes begin to condense
  • extensive synthesis of tubulin
42
Q

Tubulin

A

protein to make microtubules

43
Q

Prophase

A

The condensed chromosomes become visible
The nuclear envelope breaks down.
The assembly of the spindle takes place

44
Q

Spindle apparatus

A

assembly that carries out separation of chromosomes during cell division

45
Q

What is the spindle apparatus made up of?

A

Centrosomes (Centrioles) and Microtubules

46
Q

What structure separates sister chromatids during prophase?

A

Spindle apparatus

47
Q

What events occur during prophase?

A
  • Chromosomes condense and become visible
  • Cytoskeleton is disassembled
  • Golgi and ER are dispersed
  • Nuclear envelope breaks down
48
Q

What events occur during prometaphase?

A
  • Kinetochores attach condensed chromosomes to spindle
  • Microtubules pull sister chromatids to equator of the cell
49
Q

What evens occur during metaphase?

A
  • Chromosomes align in center of the cell
50
Q

Metaphase plate

A

imaginary plane through the equator of the cell

51
Q

What is the shortest phase in mitosis?

A

Anaphase

52
Q

What events occur during anaphase?

A
  • Proteins holding sister chromatids together at centromere are removed
  • Sister chromatids move apart toward poles
53
Q

Anaphase A

A
  • kinetochores are pulled toward the poles
  • microtubules connecting kinetochores shorten
  • tubulin subunits are removed
54
Q

Anaphase B

A
  • poles move apart
  • microtubules slide past each other towards the poles
  • physically elongate cell
55
Q

What events occur during telophase?

A
  • spindle apparatus disassembles
  • nuclear envelope forms around each set of sister chromatids
56
Q

What phase in mitosis is the reversal of the process of prophase?

A

Telophase

57
Q

The cleavage furrow is composed of _____________

A

actin filaments

58
Q

A cell plate forms partitioning the daughter cells by fusing with the

A

plasma membrane

59
Q

Formation of cell plate

A

Cellulose is laid down on the new membranes = two new cell walls

The space between the two cell walls become the middle lamella

60
Q

What are two irreversible steps in the cell cycle?

A
  1. duplication of the genome (G2 phase)
  2. Separation of sister chromatids (anaphase)
61
Q

Cyclin-dependent kinase (Cdk)

A

protein kinase enzyme only active when complexed with cyclin

62
Q

Cyclin

A

regulatory protein required to activate Cdk

63
Q

How does MPF control the cell cycle?

A
  • Cyclins accumulate in G2 and associate with MPF -> initiates mitosis
  • MPF contributes to breaking up nuclear envelope (prometaphase)
  • MPF is involved in chromosome condensation and spindle formation (prophase)
64
Q

g1/s checkpoint

A

primary checkpoint where cell decides to divide or not

65
Q

The ______ checkpoint is most susceptible to external signals

A

G1/S

66
Q

What would halt the cell cycle at the g1/s checkpoint?

A
  • damage to DNA
  • starvation conditions
  • lack of growth factors
67
Q

g2/m checkpoint

A
  • stimulates mitosis to start
  • assesses success of DNA replication
  • stalls cycle if DNA has not been accurately replicated
68
Q

Spindle checkpoint

A

ensures all chromosomes are attached to spindle in preparation for anaphase

69
Q

Anaphase promoting complex (APC)

A

sends the signal that all chromosomes are aligned properly at metaphase plate

70
Q

What is the function of the APC?

A

Trigger anaphase

71
Q

What are the two main functions of APC?

A
  1. Activates protease - destroys cohesion proteins holding sister chromatids together
  2. Necessary for destruction of mitotic cyclins to drive cell out of mitosis
72
Q

Cells stop at g1/s checkpoint if they are deprived of ___________

A

growth factors

73
Q

Describe the characteristics of binary fission.

A

Like the cell cycle – two new daughter cells are produced
Each have identical genomes
Most bacteria have a single circular chromosome
occurs much faster than eukaryotic cell division
less DNA is broken down

74
Q

Which ‘events’ in the cell cycle are considered irreversible?

A

Duplication of genome

Separation of sister chromatids

75
Q

t or f: Duplication of the genome occurs prior to M-Phase

A

true

76
Q

_________ activates MPF.

A

Cyclin

77
Q

Match the following events with the correct phase of Mitosis.

A

Interphase:
- Genome duplicates
- The G1/S checkpoint
- Chromosomes begin to condense

Prophase:
- The spindle apparatus begins to form
- Nuclear envelope degrades

Metaphase:
- Sister chromatids align on the metaphase plate

Anaphase:
- Sister chromatids pull apart
- Cells poles begin to pull apart

Telophase:
- Nuclear envelope reforms

78
Q

T or F: Two attached sister chromatids are considered a single chromosome.

A

True

79
Q

Why is it necessary for the nuclear envelope to be disassembled early in mitosis?

A

To allow microtubules to attach to the sister chromatids