Chapter 11/12- Cell division Flashcards

1
Q

Necessary for the growth of organisms, for wound healing, and to replace cells that are lost regularly, such as those in your skin and in the lining of your gut.

A

Cell Division

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2
Q

All species of organisms __________ and ____________ to pass on the hereditary information

A

Grow; Reproduce

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3
Q

Name 2 types of Cell Division

A

Bacterial Cell Division; Eukaryotic Cell Division

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4
Q

Bacteria divide as a way of

A

reproducing themselves

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5
Q

Although bacteria exchange DNA, they do not have a ______________ like eukaryotes

A

sexual cycle

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6
Q

All growth in a bacterial population is due to ___________________

A

division to produce new cells

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7
Q

reproduction of bacteria is

A

clonal

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8
Q

Each cell produced by cell division is an identical copy of the original cell

A

Clonal reproduction

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9
Q

Cell division in both bacterial and eukaryotic cells produces

A

two new cells with the same genetic information as the original

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10
Q

In Cell division in both bacterial and eukaryotic cells, what are essentials of the process which are the same,

A

duplication and segregation of genetic information into daughter cells, and division of cellular contents

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11
Q

___________have a genome made up of a single, circular DNA molecule found in the nucleoid

A

Bacteria

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12
Q

Circular DNA of bacteria held together by

A

structural maintenance of chromosome , (SMC) proteins

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13
Q

In eukaryotes the ________ and _________ proteins are SMC proteins

A

cohesin and condensin proteins are SMC proteins

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14
Q

Causes replication of DNA and division of cell into 2 cells

A

Binary Fission

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15
Q

A sexual reproduction by division of 1 cell or body into 2 equal or nearly equal parts

A

Binary fission

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16
Q

Binary Fission occurs in

A

Bacteria

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17
Q

produces two identical cells with the same genetic information as the original cell

A

Binary Fission

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18
Q

What are the steps of Binary Fission

A
  1. DNA replication
  2. Cell Elongation
  3. Cell Division
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19
Q

Binary Fission: DNA replication

Describe.

A
  1. Begins with the replication of the bacterial DNA at a specific site—the origin of replication (origin point)
  2. Enzymes for DNA duplication continue until they meet each other (finished replicating)
  3. Origin point of each DNA are in opposite directions: DNA proceeds both directions around the circular DNA to a specific site of termination
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20
Q

Binary Fission: Cell Elongation

Describe.

A
  1. As DNA replication completes, the origin moves to opposite sides of the cell, causing elongation (growth) of the cell
  2. Nucleoids are assembled around each circular DNA
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21
Q

Binary Fission: Cell Division

Describe.

A
  1. Once DNA is segregated, the midline is cleared of remaining nucleoids and cell division occurs
  2. production of septum (the wall) occurring at the midpoint of the cell forms the cell wall for the daughter cells
  3. The septum will pinch pinch off
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22
Q

During replication, first the origin, then the rest of the newly replicated chromosomes are moved to opposite ends of the cell as two new nucleoids are assembled

The final event of replication is decatenation (untangling) of the final replication products.

After replication and segregation, the midcell region is cleared of daughter nucleoids, and division occurs.

The force behind chromosome segregation has been attributed to DNA replication itself, transcription, and the polymerization of actinlike molecules.

The cell’s other components are partitioned by the growth of new membrane and production of the septum (A wall between two cavities.) This process, termed septation, usually occurs at the midpoint of the cell

It begins with the formation of a ring composed of many copies of the protein FtsZ. Proteins assemble into ring and facilitate septation and cell division

A

chromosome segregation

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23
Q

Chromosome number varies among species (T/F)

A

True

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24
Q

Humans have _________ chromosomes and ________ pairs

A

46; 23

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25
Q

Eukaryotic DNA are packaged as ________________

A

chromosomes

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26
Q

Determines how a person’s body develops and functions

A

chromosomes

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27
Q

Human embryos missing even one chromosome

A

monosomy

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28
Q

Having an extra copy of any one chromosome

A

trisomy

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29
Q

Chromosomes are composed of ____________, a complex of DNA and protein with a significant amount of RNA

A

chromatin

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30
Q

Chromosomes are the site of _____________

A

RNA synthesis

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31
Q

Each chromosome contains a single _______________ that runs uninterrupted through the chromosome’s entire length

A

DNA molecule

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32
Q

Every 200 nucleotides =

A

DNA duplex (double strand)

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33
Q

DNA duplex (double strand) is coiled around a core of

A

eight histone proteins

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34
Q

Histones are ____________ charged because of an abundance of the basic amino acids _________ and ________. Thus, they are strongly attracted to the ___________charged phosphate groups of the DNA

A

positively ; arginine and lysine.

negatively

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35
Q

The complex of DNA duplex wound around a core of 8 histone proteins is termed

A

nucleosome

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36
Q

DNA is ________ charged while histones are ___________ charged

A

negatively

positively

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37
Q

The DNA wrapped in nucleosomes is further coiled into an even more compact structure called

A

solenoid

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38
Q

Solenoids form looped domains that form

A

densely packaged DNA

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39
Q

During mitosis, proteins are assembled into a _________ that provides a framework for the final level of compaction. This gives chromosomes their familiar X-shaped structure, and facilitates separation by the mitotic machinery

A

scaffold

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40
Q

The particular array or morphology of chromosomes an individual organism possesses is called its

A

karyotype

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41
Q

One complete set of chromosomes necessary to define an organism.

A

haploid (n)

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42
Q

refers to n number of chromosomes; one set of chromosomes

A

haploid (n)

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43
Q

For humans and many other species, the total number of chromosomes in a cell is called the ___________ number, which is twice the haploid number

A

diploid (2n)

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44
Q

For humans, the haploid number is ____ and the diploid number is ____.

A

23; 46

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45
Q

reflects the equal genetic contribution that each parent makes to offspring

A

Diploid chromosomes

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46
Q

Refers to similar structures that have the same evolutionary origin.

A

homologous

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47
Q

Refers to a pair of the same kind of chromosome in a diploid cell.

A

homologous

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48
Q

In a diploid each chromosome has a ___________

A

homologue

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49
Q

maternal and paternal chromosomes are referred to as _______________, and each 1 of the pair is termed ______________

A

homologous; homologue

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50
Q

Homologous chromosomes replicate themselves for ____________ and is held together by ___________

A

Cell division

cohesins

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51
Q

A protein complex that holds sister chromatids together during cell division.

A

cohesins

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52
Q

The loss of _________ at the centromere allows the anaphase movement of chromosomes.

A

cohesins

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53
Q

After replication, each chromosome is composed of two identical DNA molecules held together by a complex of proteins called

A

cohesins

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54
Q

Refers to either of the two identical copies (chromatids) formed by the replication of a single chromosome ________________, with both (2) copies joined together by cohesions (proteins) via a region called_____________

A

sister chromatids ; centromere

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55
Q

The region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, during cell division.

A

centromere

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56
Q

Two replicas of a single chromosome held together at their centromeres by cohesin proteins after DNA replication.

A

sister chromatids

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57
Q

Composed of proteins found at the centromere that attach to microtubules during mitosis

A

kinetochore

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58
Q

Eventually 2 sister chromatids separate, ONE in each ____________ cell.

A

daughter cell

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59
Q

portion of DNA that is not expressed as RNA

A

Heterochromatin

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60
Q

portion of DNA that is expressed as RNA

A

Euchromatin

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61
Q

The repeating sequence of growth and division through which cells pass each generation, or growth and division of eukaryotic cells

requires the duplication of the genome, its accurate segregation, and the division of cellular contents.

A

Cell Cycle

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62
Q

5 stages of Cell Cycle

A
– G1	(gap	1) phase
– S (synthesis) phase
– G2 (gap2) phase
– Mitosis
– Cytokinesis
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63
Q

The primary growth phase of the cell

A

G1 (gap 1) phase

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64
Q

Longest phase of Cell Cycle

A

G1 (gap 1) phase

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65
Q

The phase in which the cell synthesizes a replica of the genome, or DNA is replicated

A

S (synthesis) phase

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66
Q

The second growth phase, where the cell is preparing for separation of the newly replicated genome, or DNA

A

G2 (gap2) phase

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67
Q

During this phase microtubules begin to reorganize to form a spindle for mitosis

A

G2 (gap2) phase

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68
Q

G1, S, and G2 together constitute _______________ , the portion of the cell cycle between cell divisions.

A

interphase

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69
Q

Phase of the cell cycle in which the SPINDLE apparatus assembles, binds to the chromosomes, and moves the sister chromatids apart.

A

Mitosis

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70
Q

The essential step in the separation of the two daughter genomes

A

Mitosis

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71
Q

5 stages of mitosis

A

prophase, prometaphase, metaphase, anaphase, and telophase

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72
Q

phase of the cell cycle when the cytoplasm divides, creating two daughter cells

A

Cytokinesis

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73
Q

involves growth and preparation for DNA synthesis

A

G1 phase

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74
Q

a copy of the genome is synthesized

A

S phase

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75
Q

prepares the cell for mitosis

A

G2 phase

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76
Q

replicated chromosomes are partitioned

A

mitosis

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77
Q

divides the cell into two cells with identical genomes.

A

cytokinesis

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78
Q

To distinguish the dividing phase from interphase, Mitosis and cytokinesis together are usually referred to collectively as

A

M phase

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79
Q

Cells often pause in G1 before DNA replication and enter a resting state called the

A

G0 phase

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80
Q

The stage of the cell cycle occupied by cells that are not actively dividing.

A

G0 phase

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81
Q

Most of the cells in an animal’s body are in this phase

Most cells are in this phase

A

G0 phase

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82
Q

All the events that happen during G1, S, and G2 phases

A

Interphase

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83
Q

Interphase prepares chromosomes for __________

A

mitosis

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84
Q

Interphase:

1) A point of constriction on the chromosome containing repeated DNA sequences that bind specific proteins.
2) These proteins make up a disklike structure called ______________

A

1) centromere

2) kinetochore

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85
Q

Interphase:

A disk-like protein structure bound to repeating DNA
sequences on the centromere

A

kinetochore

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86
Q

Interphase:

During mitosis, microtubules will attach at ___________ and pull the sister chromatids apart

A

kinetochore

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87
Q

Interphase:

In __________ phase, the replicated chromosomes will further condense ,

A

G2 phase

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88
Q

Interphase:

Chromosomes begin the process of condensation, coiling ever more tightly in __________ phase

A

G2 phase

89
Q

Interphase:

In __________ phase, centrioles will replicate and tubulin will be synthesized (the two will form microtubules)

A

G2

90
Q

Interphase:

Protein that forms microtubules.

A

Tubuiln

91
Q

Interphase:

Involved in the rapid final condensation of the chromosomes that occurs early in mitosis

A

Special motor proteins

92
Q

M phase: Mitosis (stages)

What am I?

  • condensed chromosomes
  • condensation process continues, or further condensation of chromosomes.
  • Ribosomal RNA synthesis ceases when the portion of the chromosome bearing the rRNA genes is condensed.
  • No further production of rRNA
A

Prophase

93
Q

M phase: Mitosis (stages)

What am I?

  • spindle apparatus will assemble
  • two centriole pairs formed during G2 phase begin to move apart, forming between them an axis of microtubules (referred to as spindle fibers) until they reach opposite sides of the cell
A

Prophase

94
Q

M phase: Mitosis—-> Prophase

In animal cell mitosis, the centrioles extend a radial array of microtubules toward the nearby plasma membrane when they reach the poles of the cell. This arrangement of microtubules is called an___________

A

Aster

95
Q

M phase: Mitosis (stages)

What am I?

The nuclear envelope begins to break down

A

Prophase

96
Q

M phase: Mitosis (stages)

What am I?

During the formation of the spindle apparatus, the nuclear envelope breaks down competley and the endoplasmic reticulum reabsorbs its components

Condensed chromosomes will attach to (spindle)microtubules via kinetochores

A

Prometaphase

97
Q

M phase: Mitosis (stages)

What am I?

Occurs following the disassembly of the nuclear envelope.

A

Prometaphase

98
Q

The transitional phase between prophase and metaphase during which the spindle(microtubules) attaches to the kinetochores of sister chromatids.

A

Prometaphase

99
Q

M phase: Mitosis (stages)

What am I?

  • Condensed chromosomes become attached to the spindle by their kinetochores
  • Each chromosome possesses two kinetochores, one attached to the centromere region of each sister chromatid
A

Prometaphase

100
Q

M phase: Mitosis (stages)

What am I?

As _____________ continues, a second group of microtubules grow from the poles of the cell toward the centromeres.
These microtubules are captured by the kinetochores on each pair of sister chromatids. This results in the kinetochores of each sister chromatid being connected to opposite poles of the spindle.

A

Prometaphase

101
Q

M phase: Mitosis (stages)

What am I?

  • Second group of microtubules attach to kinetochore on centromere (opposite from the first site)
  • Results in microtubules attached to each side of the sister chromatids
A

Prometaphase

102
Q

M phase: Mitosis (stages)

What am I?

Microtubules will pull all of the chromosomes to the center of the cell

A

Prometaphase

103
Q

M phase: Mitosis (stages)

What am I?

The alignment of the chromosomes in the center of the cell

A

metaphase

104
Q

M phase: Mitosis (stages)

What am I?

Third stage of mitosis _______________

A

metaphase

105
Q

M phase: Mitosis (stages)

What am I?

The alignment of the chromosomes in the center of the cell run along the ____________________

A

metaphase plate

106
Q

M phase: Mitosis (stages)

What am I?

Not an actual structure, but rather an indication of the future axis of cell division.

A

metaphase plate

107
Q

M phase: Mitosis (stages)

What am I?

Shortest phase

A

anaphase

108
Q

M phase: Mitosis (stages)

What am I?

Begins when the cohesin proteins holding sister chromatids together at the centromere are removed

A

anaphase

109
Q

M phase: Mitosis (stages)

What am I?

Up to this point in mitosis, sister chromatids have been held together by cohesin proteins concentrated at the centromere

A

anaphase

110
Q

M phase: Mitosis (stages)

What am I?

  1. Kinetochores are pulled toward the poles as the microtubules that connect them to the poles shorten
  2. Tubulin subunits are removed from the kinetochore ends of the microtubules, and progressively disassemble
  3. Chromatids are pulled ever closer to the poles of the cell.
A

Anaphase A

111
Q

First stage of Anaphase

A

Anaphase A

112
Q

Second stage of Anaphase

A

Anaphase B

113
Q

M phase: Mitosis (stages)

What am I?

Poles move apart as microtubular spindle fibers physically anchored to opposite poles slide past each other, away from the center of the cell

A

Anaphase B

114
Q

M phase: Mitosis (stages)—> Anaphase

The kinetochores are pulled by shortening microtubules (disassembly of tubulin), resulting in _______________________, the poles then
separate as microtubules _____________________

A

sister chromatids being pulled in opposite directions (poles)

pull back to opposite poles of the cell

115
Q

M phase: Mitosis (stages)

What am I?

The nucleus re-forms during ________________________

A

telophase

116
Q

M phase: Mitosis (stages)

What am I?

  • Spindle apparatus is diassembled
  • Microtubules broken down to tubulin
  • Nuclear envelop forms around chromosomes on both sides
A

telophase

117
Q

In this phase chromosomes uncoil for gene expression and rRNA production, resulting in reappearance of the nucleolus

A

Telophase

118
Q

During telophase cytoplasmic organelles are ___________________

A

sorted into both daughter cells

119
Q

M phase: Mitosis (stages)

What am I?

Cytoplasmic organelles are sorted into both daughter cells

A

Telophase

120
Q

M phase: Mitosis (stages)

What am I?

Achieved by means of a constricting belt of actin filaments

In animal cells

A

Cytokinesis

121
Q

In cytokinesis, a belt of actin filaments slide towards each other, pinching the middle of the cell together, a structure called the ______________________

A

cleavage furrow

122
Q

The constriction that forms during cytokinesis in animal cells that is responsible for dividing the cell into two daughter cells.

A

cleavage furrow

123
Q

In cytokinesis, the __________________will deepen until the cells pinch off to form 2 daughter cells

A

cleavage furrow

124
Q

Division of the cytoplasm of a cell after nuclear division.

A

cytokinesis

125
Q

The structure that forms at the equator of the spindle during early telophase in the dividing cells of plants and a few green algae.

A

cell plate

126
Q

M phase: Mitosis (stages) —-> Cytokinesis (plants)

During telophase, center of expanding cell forms a _______________

A

cell plate

127
Q

M phase: Mitosis (stages) —-> Cytokinesis (plants)

What is the function of the cell plate?

A

Will fuse with the membrane and divide the cell into 2

128
Q

Where is the cell cycle process checked for accuracy and halted if there are errors?

A

Check Points

129
Q

Cell cycle can be put on hold at specific points called

A

Check Points

130
Q

HIGH LEVEL OF CONTROL that ensures proper division and high accuracy of chromosome replication

A

Check Points

131
Q

Proteins that start or stop each phase of the cell cycle

A

Check Points

132
Q

What are the 3 cell cycle check points

A

G1/S checkpoint

G2/M checkpoint

Spindle checkpoint

133
Q

Halts the cycle to assess internal state of cell and integrates external signals

A

check points

134
Q

A positive regulator of cell-cycle progression in the cytoplasm of dividing cells

A

maturation-promoting factor (MPF )

135
Q

Research on the activation of frog oocytes led to the discovery of a substance that was first called

A

maturation-promoting factor (MPF )

136
Q

The first MPF was discovered during

A

oocytes experiments

137
Q

What experiment is this?

Cytoplasm taken from a variety of actively dividing cells from the M phase / injected in G1 phase of cell / prematurely began mitosis, or induced cell division when injected into oocytes

A

oocytes experiments

138
Q

____________ taken from a variety of actively dividing cells from the _________ / injected in _________of cell / prematurely began ________, or induced ________ when injected into __________

A

Cytoplasm

M phase

G1 phase

mitosis

cell division

oocytes

139
Q

Oocyte experiment

____________ taken from a variety of actively dividing cells from the _________ / injected in _________of cell / prematurely began ________, or induced ________ when injected into __________

A

Cytoplasm

M phase

G1 phase

mitosis

cell division

oocytes

140
Q

A type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

A

mitosis

141
Q

True or false

Cytoplasm from M phase contains a positive regulator that causes a cell to enter mitosis

A

True

MPF

142
Q

True or False

MPF activity varied during the cell cycle

A

True
low in early G2,

rising throughout this phase,

and then peaking in mitosis

143
Q

Two key aspects of MPF:

1) MPF activity varied during the cell cycle: ______ in early ____, _______ throughout this phase, and then ______ in mitosis
2) Enzymatic activity of MPF involved the __________________________

A

low

G2

rising

peaking

phosphorylation of proteins

144
Q

MPF levels varied throughout the cell cycle this suggested _______________________ and that MPF probably had some sort of _______________ activity

A

Regulation of MPF

enzymatic (kinase)

145
Q

MPF activity variation indicated _________

Phosphorylation of proteins in MPF indicated _____________

A

Regulation of MPF

enzymatic activity

146
Q

Research in sea urchin embryos and surf clams uncovered several similar proteins named

A

cyclins

147
Q

Any of a number of proteins that are produced in synchrony with the cell cycle and combine with certain protein kinases, at certain points during cell division.

A

cyclins

148
Q

Do cyclins have kinase activity?

A

No

149
Q

How are cyclins similar to MPF

A

Varied levels throughout cell cycle

150
Q

Cyclins were found to bind to protein kinases called

A

cyclin-dependent kinase (Cdk)

151
Q

Cyclin-dependent kinase, or CDK is expressed by what gene

A

CDC2 gene

152
Q

cyclin plus cdc2 =

A

MPF

153
Q

A protein kinase enzyme that is only active when complexed with cyclin.

A

cyclin-dependent kinase (Cdk)

154
Q

composed of both a cyclin component and a kinase component.

A

MPF

155
Q

cdc2 is a ___________

A

kinase, or protein

156
Q

What is MPF composed of

A

cyclin and cdc2 (kinase)

157
Q

The cyclin + cyclin-dependent kinase complex is

one type of ___________ , originally discovered in the oocyte experiment

A

MPF

158
Q

Cyclins + their kinase counterparts (cdc2/cdk1/p34… etc) =

A

maturation (mitosis) promoting factor

159
Q

Several cyclins and kinases exist and comprise a large family of ___________ & ______________

A

proteins and kinases

160
Q

What is the purpose of the cyclin + kinase complex?

A

phosphorylation of proteins associated at each check point so that the cell cycle can continue

161
Q

True or False

The cell cycle is controlled at three checkpoints

A

True

G1/S checkpoint

G2 /M checkpoint

Spindle checkpoint (late metaphase)

162
Q

Allow the cycle to be delayed or halted when necessary.

A

checkpoints

163
Q

The cell uses ____________ to both assess its internal state and integrate external signals

A

checkpoints

164
Q

Passage through these checkpoints is controlled by

A

Cdk enzymes

165
Q

The primary control point at which a cell “decides” whether or not to divide. Also called START and the restriction point.

A

G1/S checkpoint

166
Q

Primary point at which external signals can influence events of the cycle

A

G1/S checkpoint

167
Q

The phase during which growth factors affect the cycle and also the phase that links cell division to cell growth and nutrition.

A

G1/S checkpoint

168
Q

External signals may trigger or inhibit the cell cycle at this checkpoint

A

G1/S checkpoint

169
Q

G2/M checkpoint

The second cell-division control point, at which division can be delayed if DNA has not been properly replicated or is damaged.

A

G2 /M checkpoint

170
Q

Passage through this checkpoint represents the commitment to mitosis.

A

G2 /M checkpoint

171
Q

This checkpoint assesses the success of DNA replication and can stall the cycle if DNA has not been accurately replicated.

A

G2 /M checkpoint

172
Q

Cdks active at this checkpoint termed as M phase-promoting factor (MPF)

A

G2 /M checkpoint

173
Q

G2 /M checkpoint contains active cdks termed

A

M phase-promoting factor (MPF)

174
Q

A Cdk enzyme active at the G2/M checkpoint.

A

M phase-promoting factor (MPF)

175
Q

The third cell-division checkpoint, at which all chromosomes must be attached to the spindle. Passage through this checkpoint commits the cell to anaphase.

A

Spindle checkpoint

176
Q

Ensures that all of the chromosomes are attached to the spindle in preparation for anaphase.

A

Spindle checkpoint

177
Q

At this checkpoint all chromosomes are attached to spindles for anaphase, at which point the process is IRREVERSIBLE

A

Spindle checkpoint

178
Q

Enzymes that accomplish this phosphorylation

A

Cdks

179
Q

At what checkpoint does the activation of cdc2 / G1 cyclin cause the cell to continue on to S-phase

A

G1/S

180
Q

At what checkpoint does activation of cdc2 / mitotic cyclin cause the cell to continue on to M-phase

A

G2/M

181
Q

At what checkpoint does activation of APC (anaphase promoting complex) causes the cell to continue on to anaphase

A

Spindle checkpoint

182
Q

A protein complex that triggers anaphase; it initiates a series of reactions that ultimately degrades cohesin, the protein complex that holds the sister chromatids together. The sister chromatids are then released and move toward opposite poles in the cell.

A

anaphase-promoting complex (APC)

183
Q

1) What protein does anaphase-promoting complex (APC) mark for DESTRUCTION by adding ubiquitin (protein marker for degradation) ?
2) T/F

APC /C acts as a ubiquitin ligase

A

securin

true

184
Q

Acts as an inhibitor of another protease called separase

A

securin protein

185
Q

Securin protein acts as an inhibitor of another protease called

A

separase

186
Q

Separase destroys ______________

A

cohesin

187
Q

Protease which normally degrades cohesin, or the proteins that hold the sister chromatids together

A

separase

188
Q

Activates the PROTEASE that removes the cohesins holding sister chromatids together, and it is necessary for the DESTRUCTION of mitotic cyclins to drive the cell out of mitosis

A

anaphase-promoting complex (APC)

189
Q

Cyclins and kinases, or CDKs themselves are

activated via _______________________

A

phosphorylation

190
Q

Growth factors act by triggering

A

intracellular signaling systems

191
Q

______________ signals cause ______________ of Cdks

A

External

phosphorylation

192
Q

A receptor tyrosine kinase (RTK) that initiates/activates a MAP kinase cascade to stimulate cell division

A

platelet-derived growth factor (PDGF).

193
Q

When a tissue is injured, a blood clot forms, and the release of ____________triggers neighboring cells to divide, helping to heal the wound.

A

PDGF

194
Q

T/F

PDGF is not a growth factor

A

False

It is a growth factor

195
Q

1) Over how many different proteins function as growth factors?
2) These growth factor receptors often initiate MAP kinase cascades in which the final kinase enters the nucleus and activates__________________ by phosphorylation
3) Stimulates the production of G1 cyclins and the proteins that are necessary for cell-cycle progression

A

50

transcription factors

transcription factors

196
Q

Cells that are not exposed to growth factors stop at _________, checkpoint and enter _______ phase.

A

G1 checkpoint

G0 phase

197
Q

Cells remain dormant at this phase

A

G0 phase

198
Q

The unrestrained, uncontrolled growth of cells in humans leads to the disease called

A

cancer

199
Q

A disease of cell division—a failure of cell division control.

A

cancer

200
Q

What happens when cells ignore these

checkpoints? (G1, G0)

A

Cancerous cells

201
Q

The gene that produces the p53 protein

A

p53 gene

202
Q

Monitors DNA integrity and halts cell division if DNA damage is detected.

A

p53 protein

203
Q

Many types of cancer are associated with a damaged or absent

A

p53 gene

204
Q

p53 gene is abundant during__________

A

G1 phase checkpoint

205
Q

Determines chromosome integrity, checks for errors in copying DNA, DNA damage and mutations

A

p53 gene

206
Q

Helps in cell repair mechanism

A

p53

207
Q

p53 gene prevents the development of many mutated cells, and it is therefore considered a______________

A

tumor-suppressor gene

208
Q

A gene that normally functions to inhibit cell division; mutated forms can lead to the unrestrained cell division of cancer, but only when both copies of the gene are mutant.

A

tumor-suppressor gene

209
Q

p53 is also know as _________________

A

tumor-suppressor gene

210
Q

Halts division of damaged cells, can also directs cell to kill itself

A

tumor-suppressor gene

211
Q

p53 is entirely absent or damaged beyond use in the majority of __________________ cells

A

cancer

212
Q

Causes cells to proliferate uncontrollably, leading to cancer

A

Abnormal P53 function or lack of P53 protein

213
Q

Fails to stop cell division and repair DNA

A

Abnormal p53 protien

214
Q

Genes that can, when introduced into a cell, cause it to become a cancer cell

A

oncogenes

215
Q

A mutant form of a growth-regulating gene that is inappropriately “on,” causing unrestrained cell growth and division.

A

oncogene

216
Q

Normal cellular genes that become oncogenes when mutated.

A

proto-oncogenes

Ex: PDGF receptor mutation causes receptor to
always be ‘on’ in the absence of ligand

217
Q

The action of proto-oncogenes is often related to signaling by____________, and mutuation can lead to loss of _____________

A

Growth Factors

Growth Control

218
Q

Encodes for proteins (Rb protein, p53 protein) that prevent uncontrollable cell division

Cause cancer when mutated

A

Tumor-suppressor genes

219
Q

A gene that, when mutated, predisposes individuals to a rare form of cancer of the retina; one of the first tumor-suppressor genes discovered.

A

retinoblastoma susceptibility gene (Rb)