Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BI1004 - the dynamic cell > Cell cycle, stem cells, cancer > Flashcards

Cell cycle, stem cells, cancer Flashcards

(104 cards)

Start Studying
1
Q

What are the phases of the cell cycle?

A

M phase (mitosis/cytokinesis), THEN INTERPHASE = G1, S phase, G2.

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

What is the M phase divided into?

A

Continuous sub-phases.

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

What are the sub-phases that M phase is divided into?

A

Mitosis - prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis.

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

What happens in G2 of interphase during cell division by mitosis?

A

Chromosomes condense, nuclear env dissolves, centrosome replicate.

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

What happens at prophase of cell division of mitosis?

A

Chromosomes fully condense, spindle forms.

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

What happens during metaphase during cell division by mitosis?

A

Chromosomes align at equator.

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

What happens at anaphase during cell division by mitosis?

A

Spindle contracts, chromatids separate.

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

What happens at telophase and cytokinesis during cell division by mitosis?

A

Chromosomes reach poles of cells, nucleus reforms, spindle degrades.

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

What joins chromosomes and what is this?

A

Cohesin - a multi subunit protein that forms a loop between subunits.

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

How does cohesin join chromosomes?

A

Forms a dimer loop, two helices of DNA captured inside loop.

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

What causes DNA condensation?

A

Multiple rounds of folding and coiling.

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

What is used to condense chromosomes and what is this?

A

Final condensation by condensin - a multi subunit dimerises.

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

How does condensin condense chromosomes?

A

Dimers loop around DNA, securing loops, DNA loops through neck of ring.

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

How is the structural maintenance of chromosomes (SMC) complexes ensured?

A

Via coordinated activity of cohesin and condensin which enables chromatids to condense into 300nm fibres and looped domains.

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

What allows condensin and cohesin to work so well together?

A

Have very similar structures as are descended from the same bacterial protein.

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

What is the role of the spindles?

A

Microtubules form a network, connect poles of each cell and membranes, bind chromosomes, facilitate chromosomes movement.

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

Where are spindles/microtubules produced from?

A

By the centrioles - two centrioles in a centrosome.

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

At what degrees are centrioles at from each other?

A

90 degrees.

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

How many sets of microtubules are in the spindle?

A

Three.

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

What are the different kinds of spindle interactions?

A

Bind to plasma membrane, fix spindle in place, affix to chromosomes, affix to other microtubules in the spindle.

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

How are mitotic spindles formed?

A

Tubulin molecules become polymerised into spirals to form microtubules.

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

What is the role of dynein in spindles interacting with themeselves?

A

Attaches astral microtubules to plasma membrane.

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

What is the role of kinesin-14 and kinesin-5 in spindles interacting with themselves?

A

Tightens spindle, expands spindle.

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

What is the role of kinesin -4, -10 in spindles interacting with themeselves?

A

Moves chromosomes to poles of the microtubules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the centromere?
The single point along chromatids length where they’re joined together, is visible in condensed chromosomes as constricted region, dense and tightly structured DNA, devoid of genes.
26
What does DNA have little affinity for?
Mitotic spindles.
27
What is the kinetochore and its role?
Where spindle attaches, consists of several proteins and three layers.
28
What are the three layers of the kinetochore?
Checkpoint - collar to attach spindle, outer - structural, inner - binds to DNA.
29
How are chromosomes orientated during metaphase?
So that one chromatid faces each pole of the spindle so they can attach.
30
What orientates the chromosomes?
Kinetochore and kinesins enable chromosome to walk to ends of spindle fibres.
31
What is the role of separase?
Allows chromatids to separate.
32
What is formed and then separated during anaphase?
Anaphase promotion complex.
33
How are spindles shortened via the Pac-Man flux mechanism?
Removal of tubulin from +end, force pulls kinetochore to pole, also removal of tubulin from minus end, depolarisation of plus end of kinetochore microtubules, kinetochore.
34
What’s the difference between anaphase A and B?
A = separation of chromatids, B = separation of spindle cores.
35
What does meiosis generate?
Gametes.
36
What are the key characteristics of meiosis?
Is rare, normally restricted to reproductive organs, results in genetic variety, source of biological diversity.
37
What are the sub sections of prophase 1?
Leptotene, zygotene, pachytene, diplotene, diakinesis.
38
What does meiosis produce?
Gametes or sex cells.
39
What is bivalent formation during meiosis 1?
Chromosomes fuse at chiasma = crossover.
40
What happens during prophase - leptotene?
Chromosomes condense, equivalent to processes in prophase in mitosis.
41
What happens during prophase - zygotene?
Chromosomes align with homologous pair, synaptonemal complex begins to form, joins homologous chromosomes together along length of chromatids.
42
What happens during prophase - pachytene?
Chromosomes aligned fully in pairs, synapses complete, chromatids joined along lengths, crossover events occur by breakage of DNA and re-fusion with alternate chromatid.
43
What happens during prophase - diplotene?
Synaptonemal complex dissolves, leaving chromatids free, homologous chromosomes still joined together only via crossover junctions, bivalents/tetras visible under microscope.
44
What happens during prophase - diakinesis?
Bivalents associate with the meiotic spindle, orientate in homologous pairs at equator of cell, one homologue attached to each spindle pole.
45
What facilitates crossover and what is this?
Synaptonemal complex dissolves - a collection of proteins and chromosomal structures acting like a zip to bring chromatids together.
46
How is crossover undertaken?
Lateral elements + central elements bind chromatids of homologous chromosomes together, draw DNA strands close and enables breaks in DNA.
47
Why do larger chromosomes have more crossover events?
Bivalents are not simple.
48
What separates and what remains together during anaphase 1?
Homologous chromosomes separate, chromatids stay attached together.
49
What do crossovers enable?
Complete transferral of DNA regions from one chromosome to another, mixes up DNA from either parent.
50
What happens during meiosis 1 - metaphase 1?
Homologous pairs line up at the equator, one kinetochore per chromosome attached to spindle.
51
What common process in humans happens at metaphase 1 of meiosis?
Most egg cells are suspended.
52
What happens during anaphase 1 of meiosis 1?
Replicated pairs of chromatids move towards the poles of the cell.
53
What happens during meiosis 1, telophase 1?
Nuclear membrane begins to reform, chromosomes decondense.
54
What is the process of cytokinesis in meiosis 1?
Chromosomes enter an interphase of varying lengths of time.
55
What are the steps of meiosis 2 - prophase 2?
Chromosomes condense and attach to spindle.
56
How is metaphase 2, meiosis 2 completed?
Chromosomes line at equator of cell, each chromatid attached to spindle.
57
What are the steps of anaphase 2, meiosis 2?
Chromosomes pulled apart, chromatids seperate and pulled to opposite ends of cell.
58
What is the process of telophase 2 and cytokinesis in meiosis 2?
Chromosomes de-condense, nuclear membrane reforms, cytokinesis.
59
What are the key comparisons between mitosis and meiosis respectively?
2 cells produced vs 4, cells genetically identical to parent vs different, identical to each other vs different, daughter cells 2n or 2c vs n or c.
60
What is a simple overview of the steps of mitosis?
Chromosomes replicate, condense, line up individually at equator, chromatids separate, nuclear membrane reforms, cytokinesis.
61
What is a simple overview of the steps of meiosis?
Chromosomes replicate, condense, pair with homologous partner, crossover, homologous pairs separate, cytokinesis, chromosomes condense, line up individually at equator, chromatids separate, cytokinesis.
62
What is the contractile ring?
Used in cytokinesis, actin and myosin filaments, associated with plasma membrane, in cleavage furrow, interpolar microtubules from central spindle.
63
How does cytokinesis happen in animal cells?
Microtubules form a contractile ring-cleavage furrow.
64
How is cytokinesis undergone in plant cells?
Phragmoplast new cell wall (cell plate), microtubules trapped in middle, plasmodesmata, occurs by construction of dividing wall between cells
65
When are asymmetric cell division produced instead of equal ones?
During gamete production asymmetric cell divisions are common.
66
What is an example of where cytokinesis doesn’t follow mitosis?
Drosophila fruit fly embryo, mitosis occurs without cell division to replicate several nuclei.
67
What are cell lineages?
Gamete, zygote, embryo, germ layers, tissues, stem cells.
68
What are undifferentiated cells?
Cells require genetic determination to develop and differentiate.
69
What can undifferentiated cells control?
Gene expression, pre-existing mRNA, pre-existing proteins.
70
What state do stem cells replicate in and what do they differentiate due to?
Undifferentiated state, due to environmental or genetic cues.
71
What are the different types of potency?
Totipotent, omnipotent, pluripotent, multipotent, oligopotent, unipotent.
72
What does totipotent/ omnipotent mean?
Can differentiate into anything usually zygote/ very early embryo cells.
73
What does pluripotent mean?
Can differentiate into most cell types.
74
What is multipotent?
Can differentiate into specific related cell types.
75
What is oligopotent?
Can differentiate into a few cell types.
76
What is unipotent?
Specified for only one cell type.
77
What does haemopoeitic stem cells mean?
Differentiation in stages.
78
What are stem cells populations established in?
Niches.
79
What are niches?
Specific locations that regulate participation in tissue generation, maintenance and repair.
80
How do niches protect stem cells?
Restricts over-active stem cells from proliferating across organism.
81
What kind of cues maintain niches?
Genetic and physiological.
82
What are the different types of somatic stem cells?
Adult, foetal, amniotic.
83
What is an example of adult stem cells?
Bone marrow - mostly multipotent.
84
What are examples of foetal stem cells?
Early-differentiating organs, umbilical cord tissues.
85
Where are amniotic stem cells located?
Free-floating in amniotic fluid.
86
What cells do meristems contain in relation to stem cells?
Undifferentiated dividing cells.
87
What is the SAM?
Shoot apical meristem.
88
What are the two other meristems beside SAM?
Lateral and root apical (RAM).
89
What potency are almost all plant tissues?
Totipotent.
90
What are the other types of stem cells beside somatic?
Embryonic and induces pluripotent (iPS).
91
What are embryonic stem cells?
From early embryonic tissues - inner cell mass.
92
What are the steps of producing and iPS cell?
Fibroblast cell from transgenic mouse, mouse transgenic for Ab resistance gene linked to pluripotency gene promoter, add genes to active promoter, select cells for active promoter, inject embryos of normal mice, cross chimaeric mice to normals.
93
What are four uses of undifferentiated cells?
Transformation, therapeutics, research, tissue engineering.
94
What tissue is used to undergo transformation of plant cells?
CALLUS tissue.
95
What exists in yeast that affects the cell cycle?
Cell division cycle mutants (cdc) mutants.
96
What does the cdc2 gene in yeast control?
The transition from G2 to M and G1 to S.
97
What does CDC2 encode to produce protein kinase?
Cyclin-dependent kinase (Cdk1).
98
What does the Cdk1 enzyme do?
Catalyses phosphorylation of lamins, leading to nuclear envelope breakdown.
99
What is cancer?
Unregulated proliferation of cells, no control to restrict numbers of cells.
100
What do tumour suppressor genes do (TSGs)?
Limit cell division, promote cell death (apoptosis).
101
What do oncogenes do?
Encourage cell proliferation, gain of function mutations.
102
What does p53 regulate?
Cell cycle and initiate cell death if necessary.
103
What are the four different therapies for cancer?
Surgery, radiotherapy, chemotherapy, pharmaceuticals.
104
What does the cancer stem cells model suggest?
Only a small population of cells divide.

BI1004 - the dynamic cell (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions