Brainscape's Knowledge GenomeTM

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


See full index

Cancer > Cell Cycle Control > Flashcards

Cell Cycle Control Flashcards

1
Q

Why is cell division required?

A

For an organism to grow, mature and maintain tissues

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

What is mitosis?

A

Mitosis is the process of dividing the duplicated DNA of a cell into 2 new nuclei.

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

What are the stages of mitosis?

A
  • Prophase
  • Prometaphase
  • Metaphase
  • Anaphase
  • Telophase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens after mitosis to form 2 new cells?

A

Cytokinesis

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

What happens during Prophase?

A
  • The DNA condenses, organises and the classic chromosome structure appears
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What happens during Prometaphase?

A
  • Microtubules attach to the chromosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens during Metaphase?

A
  • Where the chromosomes align
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens during the Anaphase?

A
  • Where the chromosomes separate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens during Telophase?

A
  • Nuclear membranes reappear around the two sets of chromosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens during cytokinesis?

A
  • Two new cells are formed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

For many eukaryotic cells, a cell is duplicated every _____ hours.

A

24 hours

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

Where is most of the life of a cell spent?

A

In interphase

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

What are the stages in interphase?

A
  • G1
  • S phase
  • G2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens during the G1 phase?

A
  • G1 (Gap 1) is the first growth stage of interphase. Cell crowns and doubles the number of organelles
  • The cell grows to nearly its full size and performs many of its specific biochemical functions that aid the organism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens during the S phase?

A
  • DNA replication- During the S phase the DNA in the nucleus is replicated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens during the G2 phase?

A
  • During G2 (Gap 2) is where the cell finishes growing
  • Once the cell has duplicated DNA in the nucleus and 2 centrosomes have appeared in the cytoplasm, mitosis can begin.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How long does the mitotic phase last for a typical eukaryotic cell?

A

80 minutes

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

Outline the whole process of mitosis (long answer)

A
  • The classical chromosome structure is seen, which occurs through a condensation process
  • At the same time, protein strands called microtubules appear from the centrosomes in animals
  • A structure found within the nucleus, the nucleolus, disappears
  • Prometaphase begins when the nuclear membrane is broken down
  • At the same time microtubule strands are growing from the centrosomes
  • These strands attach to a protein structure called the kinetochore
  • One kinetochore is attached to the centromere of each sister chromatid
  • Then metaphase occurs where the sister chromatids align along the centre of the cell so that both chromatids face toward opposite poles of the cell
  • Next Anaphase occurs where the sister chromatids are separated by a shortening of the microtubules attached to the kinetochores.
  • The poles of the cell move farther apart and cause increased separation of sister chromatids.
  • At the end of anaphase, the sister chromatids have moved to two ends of the cell
  • During Telophase is where the components of the new cells begin to appear. At this point the spindle fibres are broken up.
  • A new nuclear membrane surrounds the chromosomes at the end of each cell and the chromosomes uncoil and return to an uncondensed state.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Outline the process of cytokinesis (long answer)

A
  • First the cell is compressed by a contractile ring that divides the cell in nearly equal halves
  • Then the organelles in the cell have been replicated and are divided between the two halves of the cell - including mitochondria, Golgi bodies and rough ER - plant cells will also have chloroplasts
  • Once split the cells are in G1 stage of interphase
20
Q

How long is the cell cycle for embryonic cells?

A

2 hours

21
Q

How long is the cell cycle for cells in adults

A

20-24 hours

22
Q

What are the main points to remember about the G1 stage:

A
  • Cells are metabolically active
  • Cell increases in size
  • Cell doubles its organelles such as ribosome and mitochondria
  • Cells gather precursors/factors that will be used for DNA synthesis
  • Chromosomes in nucleus are decondensed
23
Q

What are the main points to remember about the S phase:

A
  • DNA replicates -> Each chromosome is duplicated
  • The sister chromatids will remain attached by the centromere until the end of mitosis
  • Kinetochores develop on either side of the centromere during cell division
24
Q

What is a chromatid

A
  • Copy of a duplicated chromosome
  • 2 copies are called sister chromatids
25
Q

What are the main points to remember about the G2 stage:

A
  • Cell increases in size further
  • Cell synthesises proteins that will assist cell division such as tubulin (main component of microtubules)
  • Centrosome is duplicated and both copies remain together on one side of the nucleus
26
Q

What are microtubules and why are they important?

A
  • The mitotic spindle is made of microtubules
  • The mitotic spindle separates daughter chromosomes to opposite poles of the cell
  • Mitosis required microtubules
27
Q

What is the centrosome?

A
  • The centrosome is the principle microtubule organising centre
  • The centrosome must be duplicated before M phase begins (cell division)
28
Q

What are the 3 classes of spindle microtubules (MT)?

A
  1. Astral
  2. Kinetochore
  3. Overlap microtubules (interpolar)
29
Q

What are Astral microtubules?

A

They radiate from the centrosome and contribute to pole separation

30
Q

What are Kinetochore microtubules?

A

They attach to the kinetochore on the duplicated chromosome

31
Q

What are overlap microtubules (interpolar)?

A

They overlap at the equator and are responsible for bipolar shape of the spindle

32
Q

What are the two microtubule motor proteins?

A

Kinesins and Dyneins

33
Q

What do Kinesins do?

A

Kinesins are microtubule motor proteins that move towards the positive end of a microtubule (from centre towards periphery)

34
Q

What do Dyneins do?

A

Dyneins are microtubule motor proteins that move towards the microtubules negative end

35
Q

Why are Kinesins important?

A
  • They are important for proper spindle length
  • Involved in sliding microtubules apart within the spindle during prometaphase and metaphase
  • Involved in depolymerising microtubules minus ends at centrosome during anaphase
36
Q

Why are Dyneins important?

A
  • Involved in the movement of chromosomes and positioning the mitotic spindles for cell division
37
Q

When are microtubules in their dynamic state?

A

Before entering prophase

38
Q

What is catastrophe in microtubules?

A

Period of growth to shrinkage

39
Q

What is rescue in microtubules?

A

Period of shrinkage to growth

40
Q

What does the phosphorylation of microtubule-associated protein (MAP) and catastrophins do?

A

Alters the stability of microtubules at the positive end and governs assembly of the mitotic spindle

41
Q

What is the contractile ring?

A

It is the cytoskeletal structure responsible for cytokinesis

42
Q

What is the contractile ring made of?

A

Mainly of actin and myosin filaments

43
Q

How does the contractile ring work?

A
  • It is arranged in a ring around the equator of the cell
  • It starts to assemble beneath the plasma membrane at the end of mitosis
  • As the ring contracts it pulls the membrane inward, dividing the cell in two
  • It disassembles completely once the cell is divided in two
44
Q

The progress of the cell cycle needs to carefully controlled by what 3 factors?

A
  • In sequence
  • In timing
  • In response to external signals and internal
45
Q

How do cells control their proliferation?

A

By controlling the activity of their proteins

46
Q

How do cells control the activity of their proteins?

A
  1. Phosphorylation / Dephosphorylation
  2. Make more / Inhibit and degrade

Cancer (9 decks)

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