Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IB Biology > 1.6 Cell division > Flashcards

1.6 Cell division Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is the cell cycle?

A

An ordered set of events which culminates the division of a cell into two daughter cells

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

What are the two main phases of the cell cycle?

A

Interphase and M phase

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

What is interphase?

A

The stage in the development of a cell between two successive divisions

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

What are the three stages of interphase?

A

G1
S
G2

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

What is G1 phase?

A

First intermediate gap stage where the cell grows and prepares for DNA replication

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

What is S phase?

A

Synthesis stage where DNA is replicated

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

What is G2 phase?

A

Second intermediate gap stage where the cell finishes growing and prepares for cell division

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

What is M phase?

A

The period of the cell cycle where the cell and contents divide into two genetically identical daughter cells?

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

What is mitosis?

A

Nuclear division where DNA is separated into two identical nuclei

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

What is cytokinesis?

A

Cytoplasmic division where cellular contents are segregated and the cell splits into two

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

What are the stages of M phase?

A

Mitosis and cytokinesis

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

When in the cell cycle do many metabolic reactions occur?

A

Interphase

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

What processes need to occur for interphase to prepare the cell for successful division? (doctor)

A

DNA replication
Organelle duplication
Cell growth
Transcription/Translation
Obtain nutrients
Respiration

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

What is DNA replication in interphase?

A

DNA is copied during the S phase of interphase

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

What is organelle duplication in interphase?

A

Organelles must be duplicated for twin daughter cells

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

What is cell growth in interphase?

A

Cytoplasmic volume must increase prior to division

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

What is transcription/translation in interphase?

A

Key proteins and enzymes must be synthesised

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

What is obtain nutrients in interphase?

A

Vital cellular materials must be present before the division

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

What is respiration in interphase?

A

ATP production is needed to drive the division process

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

How is DNA usually packed within the nucleus?

A

Loosely as unravelled chromatin

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

What is DNA accessible to as chromatin?

A

To transcriptional machinery

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

What does the fact that DNA is accessible to transcriptional machinery mean?

A

Genetic information can be translated

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

When and where is DNA organised as chromatin?

A

In all non-dividing cells and throughout interphase

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

How is DNA packaged prior to division?

A

Into a tightly wound and condensed chromosome

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

How is DNA packaged into a chromosome?

A

Supercoiling

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

As a chromosome, what is DNA inaccessible to?

A

Transcriptional machinery

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

As chromosome, what is DNA able to do easily?

A

Be easily segregated

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

When is DNA organised as chromosomes?

A

During mitosis

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

When is chromosome visible?

A

During mitosis

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

What is a chromosome?

A

A condensed form of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Why will the chromosome initially contain two identical DNA strands?

A

As DNA is replicated during S phase of interphase

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

What are genetically identical DNA strands called?

A

Sister chromatids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What holds sister chromatids together?

A

The centromere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What happens when chromatids separate during mitosis?

A

They become independent chromosomes each made of a single DNA strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the four stages of mitosis?

A

Prophase
Metaphase
Anaphase
Telophase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Where is DNA contained in interphase?

A

In a clearly defined nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What have been duplicated in interphase?

A

Centrosomes and other organelles have been duplicated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Why is the cell enlarged in interphase?

A

In preparation for division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does DNA and chromosomes do in prophase?

A

DNA supercoils and chromosomes condense

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are the five structures to comment about in prophase?

A

DNA
Chromosomes
Centrosomes
Nuclear membrane
Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What do paired centrosomes do in prophase?

A

Move to opposite poles of the cell and form microtubule spindle fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are chromosomes comprised of?

A

Genetically identical sister chromatids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What does the nuclear membrane do in prophase?

A

Breaks down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What does the nucleus do in prophase?

A

Dissolves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What do microtubule spindle fibres from the centrosomes do?

A

Connect to the centromere of each chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What does microtubule depolymerisation cause?

A

Spindle fibres to shorten in length and contract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

When does microtubule depolymerisation happen?

A

Metaphase

48
Q

What happens in metaphase when the spindle fibres shorten and contract?

A

The chromosomes align in the centre of the cell

49
Q

What three things do you need to comment on in metaphase?

A

Spindle fibres connecting
spindle fibres contracting
Chromosomes aligning

50
Q

What continues in anaphase?

A

The contraction of spindle fibres

51
Q

What does the continued contraction of spindle fibre in anaphase cause?

A

Genetically identical sister chromatids to separate

52
Q

What happens once when the chromatids separate in anaphase?

A

They are considered their own individual chromosome

53
Q

What do the genetically identical chromosomes do in anaphase?

A

Move to opposite poles of the cell

54
Q

What three things do you need to comment on in anaphase?

A

Separation of chromatids
Individual chromosomes
Opposite poles of cell

55
Q

In telophase, what happens when the two chromosomes arrive at the poles?

A

Spindle fibres dissolve

56
Q

What do the chromosomes do in telophase?

A

Decondense

57
Q

What does the nuclear membrane do in telophase?

A

Reform around each chromosome set

58
Q

When does cytokinesis occur?

A

Concurrently with telophase

59
Q

What does cytokinesis end up doing?

A

Splitting the cell into two

60
Q

What four things do you need to comment on in telophase?

A

Spindle fibres dissolve
chromosome condenses
Cytokinesis splits cell
Nuclear membrane reforms

61
Q

When is cytokinesis different?

A

In animal and plant cells

62
Q

After anaphase, in animal cells, what forms a ring around the centre of the cell?

A

Microtubule filaments

63
Q

What do the microfilaments constrict to form?

A

A cleavage furrow

64
Q

How does a cleavage furrow deepen?

A

From the periphery to the centre

65
Q

What happens when the cleavage furrow meets in the centre?

A

The cell becomes completely pinched off and two cells are formed

66
Q

Why is the cell separation described as centripetal?

A

Because it occurs from the outside to the centre

67
Q

In anaphase in plant cells, what forms in a row at the centre of the cell?

A

Carbohydrate-rich vesicles

68
Q

In plant cells what do the vesicles do?

A

Fuse together

69
Q

In plant cells, what begins to form within the middle of the cell?

A

An early cell plate

70
Q

What does the cell plate do in plant cells?

A

Extends outwards and fuses with the cell wall, dividing the cell into two distinct daughter cells

71
Q

Why is plant cell separation described as centrifugal?

A

As the separation begins in the centre and move separately

72
Q

What is the mitotic index?

A

A measure of the proportion of dividing cells

73
Q

When may the mitotic index be elevated?

A

During processes that promote division like normal growth or cellular repair

74
Q

What is mitotic an important prognostic for predicting>

A

The response of cancer cells to chemotherapy

75
Q

When identifying mitotic cells, what will cells undergoing mitosis lack?

A

Clearly defined nucleus

76
Q

When identifying mitotic cells, what do cells undergoing mitosis possess?

A

Visibly condensed chromosomes

77
Q

When identifying mitotic cells, what will prophase look like?

A

Chromosomes condensed by still confined to a nuclear region

78
Q

When identifying mitotic cells, what will metaphase look like?

A

Chromosomes aligned along the equator of the cell

79
Q

When identifying mitotic cells, what will anaphase look like?

A

Two distinct clusters of chromosomes at poles of the cell

80
Q

When identifying mitotic cells, what will telophase look like?

A

Two nuclear regions present within a single cell

81
Q

What is the mitotic index the ratio between?

A

The number of cells in mitosis and the total number of cells

82
Q

How can the mitotic index be determines?

A

Analysing micrographs and counting the relative number of mitotic cells versus non dividing cells

83
Q

What are cyclins?

A

A family of regulatory proteins that control the progression of the cell cycle

84
Q

What do cyclins activate?

A

Cyclin dependent kinases (CDKs)

85
Q

What do CDKs control?

A

Cell cycle processes through phosphorylation

86
Q

What happens when a cyclin and CDK form a complex?

A

The complex will bind to a target protein and modify it via phosphorylation

87
Q

What will the phosphorylated target protein trigger?

A

Some specific event within the cell cycle

88
Q

What happens after the target protein induced event has occured?

A

The cyclin is degraded and the CDK is rendered inactive again

89
Q

Why do cyclin concentrations need to be tightly regulated?

A

To ensure the cell cycle progresses in a proper sequence

90
Q

What do different cyclins specifically bind to and activate?

A

Different classes of cyclin dependent kinases

91
Q

When will cyclin levels peak?

A

When their target protein is required for function

92
Q

Describe cyclin levels when their target protein is not required?

A

It will remain low

93
Q

What are tumours?

A

Abnormal cell growths resulting from uncontrolled cell division

94
Q

Where can tumours occur?

A

In any tissue or organ

95
Q

What are diseases caused by the growth of tumours collectively known as?

A

Cancers

96
Q

What is a mutagen?

A

An agent that changes the genetic material of an organism

97
Q

Where will a mutagen act?

A

On the DNA or on the replicative machinery

98
Q

What are the three ways mutagens may be in origin?

A

Physical
Chemical
Biological

99
Q

What are three examples of physical mutagens?

A

Sources of radiation
Ultraviolet light
Radioactive decay

100
Q

What are chemical mutagens?

A

DNA interacting substances including reactive oxygen species and metals

101
Q

What are biological mutagens?

A

Viruses, certain bacteria and mobile genetic elements

102
Q

What are mutagens that lead to the formation of cancer further classified as?

A

Carcinogens

103
Q

What is an oncogene?

A

A gene that has the potential to cause cancer

104
Q

What are two basic classes of genes which cause mutations which cause cancers?

A

Proto-oncogenes and tumour suppressor genes

105
Q

What do proto-oncogenes do?

A

Code for proteins that stimulate the cell cycle and promote cell growth and proliferation

106
Q

What do tumour suppressor genes do?

A

Code for proteins that repress cell cycle progression and promote apoptosis

107
Q

What happens when a proto-oncogene is mutated or subjected to increased expression?

A

It becomes a cancer causing oncogene

108
Q

How are tumour suppressor sometimes referred to as?

A

Anti-oncogenes

109
Q

What is it when cancer is benign?

A

When tumour cells remain in their original location

110
Q

What is it when a cancer is malignant?

A

It spreads and invade neighbouring tissue

111
Q

What is metastisis?

A

The spread of cancer from one location to another, forming a secondary tumour

112
Q

What are secondary tumours made up of?

A

The same type of cell as the primary tumour

113
Q

What is there a strong link between smoking and?

A

The incidence of cancers

114
Q

What does cigarette smoke contain?

A

Over 4,000 chemical compounds

115
Q

How many chemical compounds are known to be carcinogenic?

A

60

116
Q

What is there a strong positive correlation between the frequency of smoking and?

A

The development of cancer

117
Q

What cancers are attributed to tobacco use?

A

Lung
Mouth
Stomach
Liver
Pancreas
Bowel

IB Biology (57 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions