4.1 Flashcards
(194 cards)
1
Q
All ________ derive from other cells.
A
cells
2
Q
The eukaryotic cell division cycle is __________
A
regulated
3
Q
Eukaryotic cells divide by ________________
A
Mitosis
4
Q
_____________is important in living organisms.
A
Cell death
5
Q
__________cell division can lead to cancer.
A
Unregulated
6
Q
______________plays important roles in the life cycle of an organism.
A
Cell division
7
Q
Four main events occur in all organisms during cell division:______________, DNA replication, DNA segregation, and cytokinesis.
A
cell division signals
8
Q
In ______________cell division __________ results in reproduction of the entire __________ organism.
A
prokaryotes
binary fission
single-celled
9
Q
______________ in prokaryotes are usually external factors such as nutrient concentration and environmental conditions.
A
Cell division signals
10
Q
Most prokaryotes have_________ chromosome, a single molecule of ______ . Often__________ but folded.
A
One
DNA
Circular
11
Q
In prokaryotes, DNA replication starts/ originates at the_____________
A
ori region.
12
Q
In prokaryotes, DNA replication ends/ terminus at the
A
ter region.
13
Q
In prokaryotes, replication occurs as the DNA moves through a
A
protein replication complex.
14
Q
When replication is complete in prokaryotes_____________ move to _________ end of cell
A
ori regions
Opposite
15
Q
In prokaryotes, protein fibers form a_______ during cytokinesis.
A
ring
16
Q
In prokaryotes, new cell wall materials are synthesized, resulting in the
A
separation of the two cells.
17
Q
In eukaryotes,_______________ conditions are often suitable for cell division.
A
Internal environmental conditions
18
Q
___________________in multicellular eukaryotes are related to the needs of the entire organism.
A
Cell division signals
19
Q
DNA replication in eukaryotes starts at
A
many origins
20
Q
Mitosis
A
Mitosis separates the newly replicated chromosomes into two new nuclei in eukaryotes.
21
Q
One copy of each chromosome
A
One copy of each chromosome ends up in each daughter cell during eukaryotic cell division.
22
Q
Cytokinesis
A
Cytokinesis proceeds differently in animal and plant cells.
23
Q
cell cycle
A
The phases a cell passes through to produce daughter cells by cell division is called the cell cycle.
24
Q
The cell cycle includes
A
The cell cycle includes interphase and M phase.
25
The nucleus
The nucleus is visible during interphase.
26
Interphase has three subphases
Interphase has three subphases: G1, S, and G2.
27
During G1 phase
During G1 phase, chromosomes are single (unreplicated).
28
Some cells enter a resting phase
Some cells enter a resting phase called G0.
29
G1 ends at the
G1 ends at the G1-to-S transition.
30
During S phase
During S phase, DNA replicates.
31
Sister chromatids
Sister chromatids remain together until mitosis.
32
During G2 phase
During G2 phase, the cell prepares for mitosis.
33
M phase includes
M phase includes mitosis and cytokinesis.
34
Specific signals
Specific signals trigger the transition from one phase of the cell cycle to another.
35
Progress through the cell cycle
Progress through the cell cycle is controlled by cyclin-dependent kinases (CDKs).
36
Protein kinases
Protein kinases catalyze transfer of a phosphate group from ATP to a protein.
37
This transfer of a phosphate group
This transfer of a phosphate group is called phosphorylation.
38
CDK is activated
CDK is activated by binding to cyclin.
39
Binding to cyclin
Binding to cyclin alters CDK's shape and exposes the active site.
40
The restriction point (R)
The restriction point (R) is a control point at the G1-to-S transition.
41
Certain proteins
Certain proteins normally inhibit the cell cycle at the R point.
42
When these inhibitory proteins are phosphorylated
When these inhibitory proteins are phosphorylated by cyclin-CDK, they become inactive.
43
Progress through the cell cycle depends
Progress through the cell cycle depends on CDKs.
44
CDKs can be regulated
CDKs can be regulated by the presence or absence of cyclins.
45
Cyclins are present cyclically
Cyclins are present cyclically: they are made only at certain times in the cell cycle.
46
Cyclin-CDKs act at cell cycle checkpoints
Cyclin-CDKs act at cell cycle checkpoints to regulate progress through the cell cycle.
47
Growth factors
Growth factors are external signals that can regulate the cell cycle.
48
Growth factors activate cyclin synthesis
Growth factors activate cyclin synthesis, thereby activating CDKs and the cell cycle.
49
DNA molecules
DNA molecules are bound to proteins to form chromatin.
50
Cohesins
Proteins that hold sister chromatids together during G2.
51
Centromere
The region where cohesin is removed during mitosis.
52
Histones
Proteins with positive charges that pack and organize DNA molecules.
53
Phosphate groups
Negative groups of DNA that are attracted by histones.
54
Nucleosomes
Beadlike units formed by interactions between DNA and histones.
55
Compact
The state of chromosomes during mitosis, making them inaccessible to replication and transcription factors.
56
Segregation
The process defined by mitosis, while cytokinesis is the division of cytoplasm.
57
Nuclei
The two genetically identical products of mitosis.
58
Prometaphase
The phase of mitosis that follows prophase.
59
Spindle
The structure that moves sister chromatids apart during mitosis.
60
Centrosome
The structure that determines the orientation of the spindle.
61
Centrioles
The two components that make up a centrosome.
62
Plane
The position determined by centrosomes at which an animal cell will divide.
63
S phase
The phase during which centrosomes replicate.
64
Opposite ends
The location to which centrosomes move during prophase.
65
Poles
The "poles" toward which chromosomes move, identified by centrosomes.
66
Kinetochores
Structures that develop on each chromatid late in prophase.
67
Prometaphase
The phase during which the nuclear envelope breaks down and the spindle forms.
68
Metaphase
The phase during which chromosomes line up at the metaphase plate.
69
Anaphase
The phase defined by the separation of chromatids.
70
M phase cyclin-Cdk
The complex that activates the anaphase-promoting complex (APC).
71
Separase
The enzyme activated by APC that hydrolyzes cohesin.
72
Spindle assembly checkpoint
The checkpoint that occurs at the end of metaphase to ensure proper chromosome attachment.
73
Daughter chromosomes
The name given to chromatids after separation.
74
Centromere
The structure shared by chromatids.
75
Chromosomes
Structures that have their own centromere.
76
Motor proteins
Kinesins and dynein found in kinetochores.
77
Microtubules
Kinetochore structures that shorten, drawing chromosomes toward poles.
78
Pinches
The action of the cell membrane during cytokinesis in animal cells.
79
Contractile ring
A ring of microfilaments of actin and myosin that forms in animal cells during cytokinesis.
80
Vesicles
Structures that appear along the plane of cell division in plant cells from the Golgi apparatus.
81
Cell membrane
The new structure formed by the fusion of vesicles in plant cells.
82
Cell plate
The beginning of the new cell wall formed from vesicle contents in plant cells.
83
Necrosis
The process that occurs when a cell is damaged or starved of oxygen or nutrients.
84
Swells
The action of a cell during necrosis before bursting.
85
Apoptosis
Programmed cell death.
86
Neighbors
The cells from which a cell detaches during apoptosis.
87
Nucleosomes
The structures cut by enzymes during apoptosis.
88
Blebs
Membranous lobes formed during apoptosis.
89
Division
The process that cancer cells lose control over.
90
Tumors
Large masses of cells formed by almost continuous division of cancer cells.
91
Benign tumors
Tumors that grow slowly and remain localized.
92
Malignant tumors
Tumors that do not resemble the parent tissue and can invade surrounding tissue.
93
Metastasis
The process when cancer cells invade surrounding tissue and travel through the bloodstream or lymph system.
94
Growth factors
Positive regulators that stimulate cell division.
95
Retinoblastoma protein (RB)
A negative regulator that inhibits the cell cycle.
96
Eukaryotic cell division cycle is ______________
regulated
97
Process by which eukaryotic cells divide
mitosis
98
Role of cell death in living organisms
important
99
Consequence of unregulated cell division
cancer
100
Aspect of an organism's life cycle where cell division is important
life cycle
101
Four main events in cell division
cell division signals, DNA replication, DNA segregation, cytokinesis
102
Result of cell division (binary fission) in prokaryotes
reproduction
103
Type of factors that are usually cell division signals in prokaryotes
external
104
Number of chromosomes in most prokaryotes
one
105
Region where DNA replication starts in prokaryotes
ori
106
Region where DNA replication ends in prokaryotes
ter
107
Structure through which DNA moves during replication in prokaryotes
protein replication complex
108
Movement of ori regions in prokaryotes when replication is complete
opposite ends of the cell
109
What happens to the cell membrane during cytokinesis in prokaryotes
pinches in
110
Type of fibers that form a ring during cytokinesis in prokaryotes
protein
111
Environmental conditions in eukaryotes suitable for cell division
internal
112
Relation of cell division signals in multicellular eukaryotes
needs of the entire organism
113
Number of chromosomes in eukaryotes
more than one
114
Where DNA replication starts on the chromosome in eukaryotes
many origins
115
Part of the cell cycle where DNA replication is limited in eukaryotes
one part
116
Process that separates newly replicated chromosomes into two new nuclei in eukaryotes
Mitosis
117
Number of copies of each chromosome in daughter cells during eukaryotic cell division
one
118
Type of cells where cytokinesis proceeds differently compared to animal cells
plant
119
Term describing phases a cell passes through to produce daughter cells
cell cycle
120
Other main phase of the cell cycle besides interphase
M phase
121
Cellular structure visible during interphase
nucleus
122
Three subphases of interphase
G1, S, G2
123
State of chromosomes during the G1 phase
unreplicated
124
Resting phase that some cells enter
G0
125
Point at which the G1 phase ends
G1-to-S transition
126
Phase during which DNA replication occurs
S
127
Structures that remain together until mitosis
sister chromatids
128
Process for which the cell prepares during the G2 phase
mitosis
129
Two processes included in the M phase
mitosis and cytokinesis
130
Type of signals that trigger transition from one phase of the cell cycle to another
specific signals
131
Type of molecules that control progress through the cell cycle
cyclin-dependent kinases (CDKs)
132
What protein kinase catalyzes the transfer of from ATP to a protein
phosphate group
133
What the transfer of a phosphate group is called
phosphorylation
134
Molecule to which CDK is activated by binding
cyclin
135
Aspect of CDK altered by cyclin binding
shape
136
Control point at the G1-to-S transition
restriction point (R)
137
Normal action of certain proteins at the R point
inhibit
138
Effect on inhibitory proteins when phosphorylated by cyclin-CDK
become inactive
139
Molecules on which progress through the cell cycle depends
CDKs
140
How CDKs can be regulated
by the presence or absence of cyclins
141
Presence of cyclins in the cell cycle
cyclically
142
external signals
growth factors
143
cyclin synthesis
What do growth factors activate, thereby activating CDKs and the cell cycle?
144
chromatin
To form what structure are DNA molecules bound to proteins?
145
cohesins
What proteins hold sister chromatids together during G2?
146
centromere
Where does cohesin remain during mitosis after most of it is removed?
147
histones
By what proteins are DNA molecules 'packed' and organized?
148
positive
What charges do histones have that attract the negative phosphate groups of DNA?
149
nucleosomes
What beadlike units are formed by the interaction of DNA and histones?
150
mitosis
During which phase are chromosomes so compact that they are inaccessible to replication and transcription factors?
151
mitosis
What process is defined by chromosome segregation?
152
cytokinesis
What is the division of cytoplasm called?
153
two nuclei
What does mitosis lead to the production of that are genetically identical?
154
five subdivisions of mitosis
What are the five subdivisions of mitosis?
155
spindle
What structure moves sister chromatids apart during mitosis?
156
centrosome
What cellular structure determines the orientation of the spindle?
157
two centrioles
What two structures make up the centrosome?
158
plane
What does the position of the centrosomes determine in an animal cell division?
159
S
During which phase do centrosomes replicate?
160
prophase
During which phase do centrosomes move to opposite ends of the nuclear envelope?
161
poles
What do centrosomes identify toward which chromosomes move?
162
late in prophase
When do kinetochores develop on each chromatid?
163
prometaphase
During which phase does the nuclear envelope break down and the spindle form?
164
metaphase
During which phase do chromosomes line up at the metaphase plate?
165
Anaphase
What is the term for the separation of chromatids?
166
M phase cyclin-Cdk
What controls the separation of sister chromatids during anaphase?
167
anaphase-promoting complex (APC)
What complex does M phase cyclin-Cdk activate?
168
separase
What does APC activate that then hydrolyzes cohesin?
169
spindle assembly
What type of checkpoint occurs at the end of metaphase?
170
APC
What does the spindle assembly checkpoint inhibit if a chromosome is not attached properly?
171
daughter chromosomes
What are chromatids called after separation?
172
centromere
What structure do chromatids share?
173
Chromosomes
What has its own centromere?
174
kinesins and cytoplasmic dynein
What motor proteins do kinetochores have?
175
kinetochore microtubules
What shortens to draw chromosomes toward poles?
176
pinches in
What happens to the cell membrane in animal cells during cytokinesis?
177
contractile
What type of ring forms in animal cells during cytokinesis?
178
Golgi apparatus
From where do vesicles appear along the plane of cell division in plant cells?
179
new cell membrane
What do these vesicles fuse to form in plant cells?
180
cell plate
What does the content of these vesicles form in plant cells?
181
Necrosis
What type of cell death occurs when a cell is damaged or starved of oxygen or nutrients?
182
swells and bursts
What happens to the cell during necrosis?
183
Apoptosis
What is the term for programmed cell death?
184
detaches
What happens to the cell's connection to its neighbors during apoptosis?
185
chromatin
What is digested by enzymes that cut DNA between nucleosomes during apoptosis?
186
blebs
What membranous lobes does the cell form during apoptosis?
187
cell division
What do cancer cells lose control over?
188
tumors
What do cancer cells form as they divide almost continuously?
189
Benign
What type of tumors grow slowly and remain localized?
190
Malignant
What type of tumors do not resemble the parent tissue and can invade surrounding tissue?
191
Metastasis
What is the process by which cancer cells invade surrounding tissue and travel through the bloodstream or lymph system?
192
Metastasis
What type of positive regulators stimulate cell division?
193
growth factors
What type of positive regulators stimulate cell division?
194
retinoblastoma protein (RB)
What negative regulator inhibits the cell cycle?
