4.3 Flashcards
1
Q
- All cells derive from other cells.
A
2
Q
- Where do all cells come from? Pre-existing cells.
A
3
Q
- Cell division is also called the cell cycle.
A
4
Q
- What processes does the cell cycle allow for? **Growth
A
repair
5
Q
- How many steps are common to all cell division? 4.
A
6
Q
- Prokaryotic cells divide by binary fission.
A
7
Q
- What regulates binary fission in prokaryotic cells? Environmental signals.
A
8
Q
- Eukaryotic cells undergo a more complex cell cycle.
A
9
Q
- The eukaryotic cell cycle includes dedicated sections for DNA replication
A
mitosis
10
Q
- What is the ori site? Where DNA replication begins in bacteria.
A
11
Q
- A mutation in the ori site may prevent replication from initiating properly.
A
12
Q
- What might a mutation in the ori site prevent? The formation of two complete copies of the bacterial chromosome.
A
13
Q
- What is disrupted if the ori regions cannot move to opposite ends of the bacterial cell? DNA segregation.
A
14
Q
- If DNA replication and segregation do not occur correctly in bacteria
A
cytokinesis may be incomplete.
15
Q
- What might be the result of incorrect DNA replication and segregation in bacteria? Daughter cells without full genetic material.
A
16
Q
- What is the likely outcome of such errors in bacterial cell division? Cell death.
A
17
Q
- What are the phases a cell passes through to produce daughter cells by cell division? The cell cycle.
A
18
Q
- During which phase is the nucleus visible and do cell functions occur? Interphase.
A
19
Q
- The duration of interphase is highly variable.
A
20
Q
- How many subphases does interphase have? 3.
A
21
Q
- What are the subphases of interphase? **G1
A
S
22
Q
- During which phase are chromosomes single (unreplicated)? The G1 phase.
A
23
Q
- The duration of the G1 phase is variable
A
from minutes to years.
24
Q
- What marks the end of the G1 phase? The G1-to-S transition.
A
25
Q
- What commitment is made at the G1-to-S transition? To DNA replication and cell division.
A
26
Q
- Some cells enter a resting phase.
A
27
Q
- What is the resting phase of the cell cycle called? G0.
A
28
Q
- During which phase does DNA replicate? The S phase.
A
29
Q
- Where do copied chromosomes remain until mitosis? Together.
A
30
Q
- During which phase does the cell prepare for mitosis? The G2 phase.
A
31
Q
- What does the cell synthesize in the G2 phase? The structures that move the chromatids.
A
32
Q
- What does the M phase include? Mitosis and cytokinesis.
A
33
Q
- When does the replication of DNA occur in the cell cycle? During the S phase.
A
34
Q
- How are chromosomes described in the G1 phase of the eukaryotic cell cycle? Single (unreplicated).
A
35
Q
- What does the cell prepare for in the G1 phase? Division.
A
36
Q
- If a nucleus in G2 has 1.6 pg of DNA
A
how much DNA did it have in G1? 0.8 pg.
37
Q
- If a cell cannot properly transition from S to G2
A
what might be disrupted? The preparation for mitosis.
38
Q
- Cell cycle regulation depends on the action of CDKs.
A
39
Q
- What does CDK stand for? Cyclin-dependent kinases.
A
40
Q
- What can a protein kinase do? Transfer a phosphate group from ATP to a protein.
A
41
Q
- What is the transfer of a phosphate group called? Phosphorylation.
A
42
Q
- What does the addition of a phosphate group change in a protein? Shape and function.
A
43
Q
- Phosphorylation can switch a protein on or off.
A
44
Q
- What type of molecule is a kinase? A protein.
A
45
Q
- What can a kinase alter in a protein target? The structure.
A
46
Q
- What can kinases do to other proteins? Switch them on and off.
A
47
Q
- How does a CDK regulate the cell cycle? By regulating proteins important in the cell cycle.
A
48
Q
- What does the name “CDK” imply? That the function of the kinase is dependent on something called cyclin.
A
49
Q
- What does cyclin do to the cyclin-CDK complex? Directs it to the target protein.
A
50
Q
- How does the kinase change the protein? Through phosphorylation.
A
51
Q
- What is the cyclin-CDK complex? Cyclin and Kinase.
A
52
Q
- Where do cyclin-CDKs act to regulate cell cycle progress? At cell cycle checkpoints.
A
53
Q
- How do cyclin-dependent kinases (CDKs) regulate the cell cycle? **By adding phosphate groups to target proteins
A
altering their activity**.
54
Q
- Once interphase is completed
A
what phase does the cell enter? Mitosis.
55
Q
- What happens to the replicated DNA during mitosis? It is segregated into two daughter cells.
A
56
Q
- What does a eukaryotic chromosome consist of before S phase? **One linear
A
double-stranded DNA molecule bound with many proteins**.
57
Q
- What is the complex of DNA and proteins referred to as? Chromatin.
A
58
Q
- How many double-stranded DNA molecules does an unreplicated chromosome contain? Only one.
A
59
Q
- What is present after replication during S phase? Two double-stranded DNA molecules called sister chromatids.
A
60
Q
- What holds sister chromatids together along most of their length? A protein complex called cohesin.
A
61
Q
- Where does most of the cohesin remain during mitosis? In a region called the centromere.
A
62
Q
- What proteins coat DNA molecules at the end of G2 and the beginning of mitosis to make them more compact? Condensins.
A
63
Q
- What proteins largely achieve the packing of DNA? Histones.
A
64
Q
- Why are histones positively charged at cellular pH? Because of their high content of the basic amino acids lysine and arginine.
A
65
Q
- How does DNA bind to histones? By ionic bonds.
A
66
Q
- What do DNA-histone interactions result in? The formation of beadlike units called nucleosomes.
A
67
Q
- During interphase
A
what does the chromatin consist of? Single DNA molecules wrapped around vast numbers of nucleosomes.
68
Q
- During interphase
A
is DNA accessible to proteins involved in replication and transcription? Yes.
69
Q
- What happens to the accessibility of DNA to replication and transcription factors once a mitotic chromosome is formed? It becomes inaccessible.
A
70
Q
- What is the genetic outcome of mitosis? Two nuclei that are genetically identical.
A
71
Q
- What does mitosis ensure? The accurate segregation of each copy of a eukaryotic cell’s multiple chromosomes into the daughter nuclei.
A
72
Q
- What are the five stages of mitosis? **Prophase
A
prometaphase
73
Q
- What determines the plane of cell division? The centrosomes.
A
74
Q
- What is the dynamic microtubule structure that moves sister chromatids apart during mitosis? The spindle.
A
75
Q
- What determines the orientation of the spindle? The centrosome.
A
76
Q
- What do centrosomes consist of in many organisms? A pair of centrioles.
A
77
Q
- When does the centrosome duplicate? During S phase.
A
78
Q
- When do the two centrosomes separate? At the beginning of prophase.
A
79
Q
- What do the separating centrosomes identify? The poles toward which chromosomes move during anaphase.
A
80
Q
- What do the cells of plants and fungi lack? Centrosomes.
A
81
Q
- What do plant and fungal cells have at each end of the cell? Distinct microtubule organizing centers.
A
82
Q
- What do the positions of the centrosomes determine in animal cells? The plane where the cell will divide.
A
83
Q
- When does the spindle begin to form? During prophase.
A
84
Q
- What happens to most of the cohesin during prophase? It is removed.
A
85
Q
- What becomes visible during prophase? Individual chromatids.
A
86
Q
- Where are sister chromatids still held together during prophase? At the centromere.
A
87
Q
- What structures develop in the centromere region late in prophase? Kinetochores.
A
88
Q
- What does each of the two centrosomes serve as? **A mitotic center
A
or pole**.
89
Q
- What forms between the poles and the chromosomes during prophase and prometaphase? Microtubules that make up the spindle.
A
90
Q
- What does the spindle serve as? A structure to which the chromosomes attach and a framework keeping the two poles apart.
A
91
Q
- What are the two groups of microtubules in the spindle? Polar microtubules and kinetochore microtubules.
A
92
Q
- What do polar microtubules do? Form the framework of the spindle and run from one pole to the other.
A
93
Q
- What do kinetochore microtubules do? Attach to the kinetochores on the chromosomes.
A
94
Q
- What do the two sister chromatids in each replicated chromosome become attached to? Kinetochore microtubules from opposite poles.
A
95
Q
- When does the separation of the chromatids occur? At the beginning of anaphase.
A
96
Q
- What controls chromatid separation? An M phase cyclin–CDK.
A
97
Q
- What does the M phase cyclin-CDK activate? The anaphase-promoting complex (APC).
A
98
Q
- What causes separation of sister chromatids? Hydrolysis of the cohesin protein by separase.
A
99
Q
- What is the cell cycle checkpoint at the end of metaphase called? The spindle assembly checkpoint.
A
100
Q
- What does the spindle assembly checkpoint inhibit if chromosomes are not properly attached? The APC.
A
101
Q
- What are chromatids called after separation? Daughter chromosomes.
A
102
Q
- What do sister chromatids share? A centromere.
A
103
Q
- What do daughter chromosomes have? Their own centromere.
A
104
Q
Here are 100 fill-in-the-blank questions based on the provided sources
A
presented chronologically:
105
Q
A
106
Q
- All cells derive from other cells.
A
107
Q
- All cells come from pre-existing cells.
A
108
Q
- Cell division
A
also called the cell cycle
109
Q
- The same 4 steps are common to all cell division.
A
110
Q
- Prokaryotic cells divide by binary fission
A
a process regulated by environmental signals.
111
Q
- Eukaryotic cells undergo a more complex cell cycle.
A
112
Q
- The eukaryotic cell cycle includes dedicated sections for DNA replication
A
mitosis
113
Q
- The ori site is where DNA replication begins in bacteria.
A
114
Q
- If the ori site is mutated
A
replication may not initiate properly.
115
Q
- A mutation in the ori site may prevent the formation of two complete copies of the bacterial chromosome.
A
116
Q
- Without proper replication
A
the ori regions cannot move to opposite ends of the bacterial cell
117
Q
- If DNA replication and segregation do not occur correctly in bacteria
A
cytokinesis may be incomplete.
118
Q
- Incorrect DNA replication and segregation in bacteria can result in daughter cells without full genetic material.
A
119
Q
- Such errors in bacterial cell division are likely leading to cell death.
A
120
Q
- The phases a cell passes through to produce daughter cells by cell division is called the cell cycle.
A
121
Q
- During interphase
A
the nucleus is visible and cell functions occur.
122
Q
- The duration of interphase is highly variable.
A
123
Q
- Interphase has 3 subphases: G1
A
S
124
Q
- During the G1 phase
A
chromosomes are single (unreplicated).
125
Q
- The duration of the G1 phase is variable
A
from minutes to years.
126
Q
- The G1 phase ends at the G1-to-S transition.
A
127
Q
- At the G1-to-S transition
A
commitment is made to DNA replication and cell division.
128
Q
- Some cells enter a resting phase called G0.
A
129
Q
- During the S phase
A
DNA replicates.
130
Q
- Copied chromosomes remain together until mitosis.
A
131
Q
- During the G2 phase
A
the cell prepares for mitosis.
132
Q
- In the G2 phase
A
the cell synthesizes the structures that move the chromatids.
133
Q
- The M phase includes mitosis and cytokinesis.
A
134
Q
- The replication of DNA occurs during the S phase of the cell cycle.
A
135
Q
- In the G1 phase of the eukaryotic cell cycle
A
chromosomes are single (unreplicated).
136
Q
- In the G1 phase
A
the cell prepares for division.
137
Q
- If the nucleus of a cell in G2 has 1.6 pg of DNA
A
it had 0.8 pg of DNA in G1.
138
Q
- If a cell is unable to properly transition from S to G2 phase
A
the preparation for mitosis might be disrupted.
139
Q
- Cell cycle regulation depends on the action of CDKs.
A
140
Q
- CDK stands for cyclin-dependent kinases.
A
141
Q
- A protein kinase can transfer a phosphate group from ATP to a protein.
A
142
Q
- The transfer of a phosphate group is called phosphorylation.
A
143
Q
- Addition of a phosphate group changes the shape and function of the protein.
A
144
Q
- Phosphorylation can switch a protein on or off.
A
145
Q
- A kinase is a protein.
A
146
Q
- A kinase can alter the structure of a protein target.
A
147
Q
- A kinase can switch other proteins on and off.
A
148
Q
- A CDK regulates the cell cycle by regulating proteins important in the cell cycle.
A
149
Q
- The name “CDK” implies that the function of the kinase is dependent on something called cyclin.
A
150
Q
- Cyclin directs the cyclin-CDK complex to the target protein.
A
151
Q
- The kinase changes the protein through phosphorylation.
A
152
Q
- The whole thing is the cyclin-CDK complex.
A
153
Q
- Cyclin-CDKs act at cell cycle checkpoints to regulate progress through the cell cycle.
A
154
Q
- Cyclin-dependent kinases (CDKs) regulate the cell cycle by adding phosphate groups to target proteins
A
altering their activity.
155
Q
- Once the cell cycle is initiated and interphase is completed
A
the cell enters mitosis.
156
Q
- During mitosis
A
the replicated DNA is segregated into two daughter cells.
157
Q
- A eukaryotic chromosome consists of one or two linear
A
double-stranded DNA molecules bound with many proteins.
158
Q
- The complex of DNA and proteins is referred to as chromatin.
A
159
Q
- Before S phase
A
each unreplicated chromosome contains only one double-stranded DNA molecule.
160
Q
- After replication during S phase
A
there are two double-stranded DNA molecules called sister chromatids.
161
Q
- Sister chromatids are held together along most of their length by a protein complex called cohesin.
A
162
Q
- At mitosis most of the cohesin is removed
A
except in a region called the centromere.
163
Q
- At the end of G2 and the beginning of mitosis
A
a second group of proteins called condensins coats the DNA molecules and makes them more compact.
164
Q
- The packing of DNA is achieved largely by proteins called histones.
A
165
Q
- Histones are positively charged at cellular pH because of their high content of the basic amino acids lysine and arginine.
A
166
Q
- DNA wraps around histones
A
binding by ionic bonds.
167
Q
- DNA-histone interactions result in the formation of beadlike units called nucleosomes.
A
168
Q
- During interphase
A
the chromatin that makes up each chromosome consists of single DNA molecules wrapped around vast numbers of nucleosomes.
169
Q
- During interphase
A
the DNA is accessible to proteins involved in replication and transcription.
170
Q
- Once a mitotic chromosome is formed
A
its compact nature makes it inaccessible to replication and transcription factors.
171
Q
- Mitosis during M phase leads to the production of two nuclei that are genetically identical.
A
172
Q
- Mitosis ensures the accurate segregation of each copy of a eukaryotic cell’s multiple chromosomes into the daughter nuclei.
A
173
Q
- Mitosis is conveniently subdivided into five stages: **prophase
A
prometaphase
174
Q
- The centrosomes determine the plane of cell division.
A
175
Q
- The spindle is a dynamic microtubule structure that moves sister chromatids apart during mitosis.
A
176
Q
- The orientation of the spindle is determined by the centrosome.
A
177
Q
- In many organisms the centrosome consists of a pair of centrioles.
A
178
Q
- During S phase
A
the centrosome duplicates.
179
Q
- At the beginning of prophase
A
the two centrosomes separate.
180
Q
- The separating centrosomes identify the poles toward which chromosomes move during anaphase.
A
181
Q
- The cells of plants and fungi lack centrosomes.
A
182
Q
- Plant and fungal cells have distinct microtubule organizing centers at each end of the cell.
A
183
Q
- The positions of the centrosomes determine the plane where the animal cell will divide.
A
184
Q
- The spindle begins to form during prophase.
A
185
Q
- During prophase
A
most of the cohesin that has held the two products of DNA replication together since S phase is removed.
186
Q
- Individual chromatids become visible during prophase.
A
187
Q
- Sister chromatids are still held together by a small amount of cohesin at the centromere.
A
188
Q
- Late in prophase
A
specialized structures called kinetochores develop in the centromere region.
189
Q
- Each of the two centrosomes serves as a mitotic center
A
or pole.
190
Q
- During prophase and prometaphase
A
microtubules form between the poles and the chromosomes to make up the spindle.
191
Q
- The spindle serves as a structure to which the chromosomes attach.
A
192
Q
- The spindle also provides a framework keeping the two poles apart.
A
193
Q
- Two groups of microtubules in the spindle are polar microtubules and kinetochore microtubules.
A
194
Q
- Polar microtubules form the framework of the spindle and run from one pole to the other.
A
195
Q
- Kinetochore microtubules attach to the kinetochores on the chromosomes.
A
196
Q
- The two sister chromatids in each replicated chromosome become attached to kinetochore microtubules from opposite poles.
A
197
Q
- Separation of the chromatids occurs at the beginning of anaphase.
A
198
Q
- Chromatid separation is controlled by an M phase cyclin–CDK.
A
199
Q
- The M phase cyclin-CDK activates another protein complex called the anaphase-promoting complex (APC).
A
200
Q
- Separation occurs because one subunit of the cohesin protein is hydrolyzed by separase.
A
201
Q
- A cell cycle checkpoint
A
often called the spindle assembly checkpoint
202
Q
- The spindle assembly checkpoint inhibits the APC if one of the chromosomes is not attached properly to the spindle.
A
203
Q
- After separation
A
the chromatids are called daughter chromosomes.
204
Q
- Sister chromatids share a centromere.
A
205
Q
- Daughter chromosomes have their own centromere.
A
