Cells: All cells arise from other cells Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Define tumour:

A

A swelling in an organism made up of cells that continue to divide in an abnormal way.

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

What type of cell division produces genetically identical cells?

A

Mitosis

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

What do the newly produced cells from mitosis replace?

A

Old/damaged cells

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

What is a diploid cell?

A

A cell that has two sets of chromosomes.

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

What type of cell division produces diploid cells?

A

Mitosis

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

What are haploid gametes?

A

Sex cells that have half the normal amount of chromosomes.

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

What type of cell division produces haploid gametes?

A

Meiosis

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

What are the two main stages that make up the cell cycle?

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

What are the three stages that occur in interphase?

A
  • Growth stage 1
    -Synthesis of DNA (S-phase)
    -Growth stage 2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens in stage Growth stage 1 during interphase?

A
  • Replication of organelles, e.g. mitochondria, ribosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens in synthesis of DNA stage during interphase?

A
  • Replication of DNA (DNA content will double)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens in growth stage 2 during interphase?

A
  • Checks that cell is ready for mitosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In what stage of interphase does cell cycle arrest occur?

A

G1

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

What happens in cell cycle arrest?

A
  • Cell cycle stops
  • Cell ‘rests’
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are checkpoints in the cell cycle?

A

Stages where the cell is checked to ensure that it is ready to move on to the next phase of the cell cycle.

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

What are checkpoints controlled by?

A

Genes that code for proteins

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

What is created through mitosis?

A

Two genetically identical daughter cells

18
Q

Give three reasons why mitosis is important in the life of an organism:

A
  • Allows the creation of new body cells for growth and repair
  • Replaces old/damaged cells
  • Embryo formation
19
Q

Give three reasons why meiosis is important in the life of an organism:

A
  • Haploid gametes are produced, allowing fertilisation
  • Genetic variation
  • Restoring chromosome number
20
Q

What are the four stages of mitosis?

A
  • Prophase
  • Metaphase
  • Anaphase
  • Telophase
21
Q

What happens in prophase?

A
  • Chromosomes condense, becoming shorter, fatter and visible
  • Spindle fibres begin to form
  • Nuclear envelope breaks down; chromosomes become free in the cytoplasm
22
Q

What happens in metaphase?

A
  • Chromosomes line up at the cells equator
  • Chromosomes attach to spindle fibres by their centromeres
23
Q

What happens in anaphase?

A
  • Chromosomes divide at their centromere, separating the pair of sister chromatids.
  • Spindle fibres contract, pulling the chromatids to opposite poles of the cell centromere first.
24
Q

What happens in telophase?

A
  • Chromatids reach the opposite poles of the cell and uncoil, becoming long.
  • Nuclear envelope forms around each set of chromosomes
  • The cell splits into two (cytokinesis)
25
Q

What is cytokinesis?

A

The reforming of the cell membrane/wall and the separation that produces two genetically identical daughter cells.

26
Q

What is a centriole?

A

Organelles that produces spindle fibres

27
Q

What is the role of the centromere in mitosis?

A

Allows chromosomes to move towards the opposite poles of the cell.

28
Q

How does chemotherapy work?

A
  • Prevents enzyme synthesis (required for DNA replication)
  • S phase will not occur
  • DNA cannot be replicated = division cannot occur
29
Q

How do drugs work to treat cancer?

A
  • Prevent spindle fibres from forming
  • One cell will have 2x normal amount of chromosomes, one cell will have none.
  • Cells are faulty and cannot divide.
30
Q

How does radiotherapy work?

A
  • Damages cells DNA.
  • Cell will not pass checkpoints in S phase
  • Causes apoptosis
31
Q

What is a carcinogen?

A

A chemical form of radiation or other agent that causes cancer

32
Q

What is the centromere?

A

The centre structure within a chromosome that joins the chromatids.

33
Q

What is a clone?

A

A group of genetically identical organisms formed from a single parent by asecual reproduction.

34
Q

What is differentiation?

A

The process by which a cell becomes specialised for different functions.

35
Q

What are homologous chromosomes?

A

A pair of chromosomes (one maternal, one paternal) that have the same gene loci and determine the same features.

36
Q

What is a mutagen?

A

Any agent that induces a mutation

37
Q

What is a mutation?

A

A sudden change in the amount or arrangement of the genetic material in a cell

38
Q

What is a photomicrograph?

A

A photograph of an image produced by a microscope

39
Q

What are stem cells?

A

Undifferentiated dividing cells that occur in embryos and adult animal tissues that require constant replacement.

40
Q

What is the tumour suppressor gene?

A

A gene that maintains normal rates of cell division and prevents the development of tumours.

41
Q

Cells lining the human intestine complete the cell cycle in a short time. Explain the advantage of this:

A

More cells can be produced to replace damaged/old cells.