Brainscape's Knowledge GenomeTM

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


See full index

A Level Biology > Cell division, cell diversity and cellular organisation > Flashcards

Cell division, cell diversity and cellular organisation Flashcards

1
Q

What are stem cells

A

Cells that are undifferentiated and have the potential to become specialised or differentiated. They are not adapted for any particular function, but are able to undergo cell division multiple times.

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

Why must division of cells take place?

A
  • Cell growth
  • Cell development
  • Tissue repair
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why is the activity of stem cells strictly controlled?

A

Rapid division - can lead to tumours

Slow division - can lead to ageing

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

What is cell potency?

A

A stem’s cell ability to differentiate into different types of cells.

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

Define totipotent

A

Potential to different into any type of cell

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

Define pluripotent

A

Potential to differentiate to all types of tissue, but not whole organism

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

Define Multipotent?

A

Can only differentiate into a range of cells within a certain type of tissue.

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

Describe when cells can be totipotent

A

The first 8-16 cells in an embryo

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

Describe when cells can be pluripotent

A

Early embryos

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

Describe when cells can be multipotent

A

Stem cells in bone marrow

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

Where are blood cells derived from?

A

Bone marrow

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

What is the scientific name for red blood cells?

A

Erythrocytes

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

Why do red blood cells need to be constantly replaced?

A

Short life span due to lack of nucleus

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

How long do neutrophils live for?

A

6 hours

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

What are the two types of animal stem cells?

A
  • Embryonic stem cells

- Tissue (adult) stem cells

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

What is the different between embryonic stem cells and adult stem cells?

A

Embryonic stem cells have a higher potency, and are therefore able to differentiate into more types of cells, whereas adult stem cells can only differentiate into specific tissues.

Embryonic - totipotent
Adult tissues stem cells - pluripotent

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

What is the source of plant stem cells?

A

Meristems (meristematic tissue)

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

Describe the potency of meristems

A

Pluripotent

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

What are the uses of stem cells?

A
  • Heart disease (muscle tissue)
  • Type 1 diabetes
  • Parkinson’s disease
  • Alzheimer’s disease
  • Treatment of burns
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Explain ethical problems associated with stem cells

A

The use of embryonic stem cells is controversial due to the differing perceptions of whether an embryo is a child or not. This allows doctors to use pluripotent cells instead of Multipotent cells found in bone marrow.
- Religious objections as well

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

What are specialised cells?

A

Cells that have differentiated

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

What are examples of specialised animal cells?

A
  • Erythrocytes
  • Neutrophils
  • Sperm cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How are erythrocytes specialised?

A
  • Bioconcave shape - increase SA:V
  • Don’t have nucleus - more space for haemoglobin
  • Flexible - can squeeze through capillaries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How are neutrophils specialised?

A
  • Multi-lobed - can squeeze through small gaps to get to site of infections
  • Granular cytoplasm contains lysosomes, that contain enzymes used to attack pathogens.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How are sperm cells specialised?

A
  • Tail and flagellum - aid movement
  • Many mitochondria - provides energy to swim
  • Acrosome (head of the sperm) - contains digestive enzymes to penetrate eggs.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are examples of specialised plant cells?

A
  • Palisade cells
  • Root hair cells
  • Guard cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How are palisade cells specialised?

A
  • Chloroplasts in mesophyll - absorb light for photosynthesis
  • Thin walls - increase diffusion rate for CO2.
  • Large vacuole - maintain tugor pressure.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How are root hair cells specialised?

A
  • Increased the surface area of the cell

- maximises water & mineral uptake

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

How are guard cells specialised?

A
  • Cell wall is thicker on one side, so creates a hoop shape.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are examples of specialised animal tissues?

A
  • Squamous epithelium
  • Ciliated epithelium
  • Cartilage
  • Muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How is squamous epithelium specialised?

A
  • Lining the lungs - one cell thick allowing for rapid diffusion.
32
Q

How is ciliated epithelium specialised?

A
  • Contains cilia

- Contains goblet cells

33
Q

How is cartilage specialised?

A
  • Flexible - prevents ends of bones rubbing together and causing damage.
  • Keeps airways open and allows oesophagus to expand when food is swallowed.
34
Q

What are examples of specialised plant tissues?

A
  • Epidermis
  • Xylem tissue
  • Phloem tissues
35
Q

How is plant epidermis specialised?

A
  • Covered by a waxy waterproof cuticle to reduce water loss.
36
Q

How is xylem tissue specialised?

A
  • composed of elongated dead cells

- Lignified for structural support

37
Q

How are phloem tissues specialised?

A
  • Contains sieve plates, within tubes.
38
Q

What are 3 organ systems

A

The digestive system
The cardiovascular system
The gaseous exchange system

39
Q

What does the digestive system do?

A
  • Takes in food and breaks down the large insoluble molecules into small soluble ones.
  • Absorbs nutrients into the bloodstream.
40
Q

What does the cardiovascular system do?

A

Moves blood around the body to provide an effective transport system.

41
Q

What does the gaseous exchange system do?

A

Brings air into the body so oxygen can be extracted for respiration and CO2 can be expelled.

42
Q

What is the importance of mitosis?

A
  • Ensures daughter cells are genetically identical
  • Growth, replacement and repair of tissues.
  • Necessary for asexual reproduction
43
Q

How does bacteria divide?

A

Binary fission

44
Q

When does DNA replicate during cell division?

A

During interphase, before mitosis

45
Q

What is the name given to DNA that has replicated during interphase?

A

Chromatids

46
Q

At what region are identical chromatids joined?

A

Centromere

47
Q

What are the 4 stages of mitosis?

A
  1. Prophase
  2. Metaphase
  3. Anaphase
  4. Telophase
48
Q

Describe Prophase during mitosis

A
  1. Chromatin coils creating chromosomes
  2. Nuclear membrane breaks down.
  3. Centrioles migrate to opposite poles
  4. Centrioles form spindle fibres, that attach to specific areas of the centromeres.
49
Q

Describe metaphase during mitosis

A

The chromosomes are moved by the spindle fibres to form a plate in the centre of the cell, called the metaphase plate.

50
Q

Describe anaphase during mitosis

A

The centromeres divides, separating each chromatids, which is pulled to opposite poles of the cells, by shortening spindle fibres.

51
Q

Describe Telophase during mitosis

A

Chromatids are now at poles and nuclear envelope reform around them. Chromosomes start to uncoil and nucleolus is formed.

52
Q

What is cytokinesis?

A

Actual division of the cytoplasm and the cell into two separate cells.

53
Q

What are the 4 phases of the cell cycle (not mitosis)

A
  • Mitotic phase
  • G1
  • S phase
  • G2
54
Q

Describe the mitotic phase

A
  • Mitosis and Cytokinesis
55
Q

Describe the G1 stage?

A
  • Organelles replicate
  • Transcription/Translation
  • Size of cell increase
56
Q

What does the S Phase mean?

A

Synthesis phase

57
Q

Describe the S phase

A
  • DNA synthesis

- Chromosomes replicated

58
Q

Describe the G2 Phase

A
  • Energy stores replaced
  • Transcription/translation
  • Chromosome repair
  • Size of cell increases
59
Q

What occurs at the metaphase checkpoint?

A

Checks for chromosomes spindle attachment

60
Q

What occurs at the G1 Checkpoint?

A

Checks for nutrients, growth and DNA damage

61
Q

What occurs at the G2 checkpoint?

A

Checks for cell size and DNA replication

62
Q

What is the purpose of meiosis occur?

A

- Production of gametes

- Produces genetic variation

63
Q

What type of process is meiosis?

A

Reduction division

64
Q

What type of cells are created by mitosis?

65
Q

What type of cells are created by meiosis?

A

4 haploid cells

66
Q

What stages are in meiosis?

A

Interphase

Meiosis 1:

Prophase 1
Metaphase 1
Anaphase 1
Telophase 1

Meiosis 2:
Prophase 2
Metaphase 2
Anaphase 2
Telophase 2
67
Q

What happens in meiosis 1?

A

Reduction division where homologous chromosomes are separated into two cells

68
Q

What happens in meiosis 2?

A

The second division involves each daughter cell being separated, forming two cells.

69
Q

What happens on Prophase 1 in meiosis?

A

Chromosomes condense, nuclear envelope disintegrates, and spindle formation.

Crossing can occur, leading to genetic variation

70
Q

What happens in Metaphase 1 in meiosis 1?

A

Homologous pairs of chromosomes assemble along the metaphase plate, instead of individual chromosomes.

71
Q

What happens in Anaphase 1 in meiosis 1?

A

Homologous chromosomes are pulled to opposite poles, however chromatids stay joined.

Sections of genes break off and recombination of genes lead to genetic variation.

72
Q

What happens in Telophase 1 of Meiosis 1?

A

Chromosomes assemble at each pole and nuclear reforms. Chromosomes uncoil.

Cytokinesis then takes place.

73
Q

What happens in Prophase 2 in Meiosis 2?

A

Chromosomes coil and nuclear envelope breaks down and spindle formation begins.

74
Q

What happens in Metaphase 2 in Meiosis 2?

A

Individual chromosomes assemble on the metaphase, and independent assortment occurs - causing genetic variation.

75
Q

What happens in Anaphase 2 in meiosis 2?

A

Chromatids of the individual chromosomes are pulled to opposite poles after division of the centromeres, towards the centrioles.

76
Q

What happens in Telophase 2 in metaphase 2?

A

Chromatids assemble at the poles. Chromosomes uncoil and nuclear envelope reforms.

Cytokinesis results in division of cells forming four daughter cells in total.

A Level Biology (13 decks)

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