Brainscape's Knowledge GenomeTM

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


See full index

Biology > 2.1.6 - Cell Division > Flashcards

2.1.6 - Cell Division Flashcards

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

The Cell Cycle

A

The cell cycle is a sequence of events that takes place in a cell, resulting in division of the nucleus and the formation of two genetically identical daughter cells

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

Stages of cell cycle

A 
Interphase :
- G1
- S
- G2
Mitotic phase 
- Mitosis
- Cytokinesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Interphase

A
  • DNA replicated and checked for errors
  • Protein synthesis
  • Organelles grow and divide e.g. Mitochondria
  • Normal metabolic processes occur e.g. Respiration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

G1

A
  • First growth phase
  • Protein synthesis
  • Organelles are synthesised
  • Cell increases in size
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

S

A
  • Synthesis phase

- DNA replicated

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

G2

A
  • Second growth phase
  • Energy stores are increased
  • DNA checked for errors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

G0

A
  • G0 is when a cell leaves the cell cycle
    Reasons for going to G0
  • Differentiation - To become specialised
  • Damaged DNA - It can no longer replicate (senescent)
  • Age - The older you are the more senescent cells you have (linked with cancer and arthritis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

G1 checkpoint

A
  • Cell size
  • Nutrients
  • Growth factors
  • DNA damage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Metaphase checkpoint

A
  • Chromosomes aligned

- Chromosomes attached to spindles

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

G2 checkpoint

A
  • Cell size
  • DNA replication
  • DNA damage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Checkpoints

A

If the conditions are not satisfied in each checkpoint the cell enters G0

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

Cancer

A
  • Caused by a mutation of genes that regulate the cell cycle
  • Uncontrolled cell growth
  • Forms a tumour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Stages of mitosis

A
  • Prophase
  • Metaphase
  • Anaphase
  • Telophase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Prophase

A
  • Chromosomes condense and coil, so they shorten and thicken
  • Chromosomes become visible
  • Nuclear envelope and nucleolus disappear
  • Centrioles move to opposite poles of the cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Early prophase

A
  • Chromosomes become visible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Late prophase

A
  • Nuclear envelope and nucleolus disappear

- Centrioles migrate

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

Metaphase

A
  • Chromosomes align at equator/ metaphase plate

- Attach to spindle by centromere

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

Anaphase

A
  • Spindle fibres contract and shorten

- Chromatids separate and move to opposite poles

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

Telophase

A
  • Nuclear envelope and nucleolus reform

- Chromosomes uncoil and become long and thin

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

Cytokinesis (Animal cells)

A

Cleavage furrow forms in the middle of the cell. The cell surface membrane is pulled inwards by the cytoplasm until it’s close enough to fuse around the middle, forming two cells.

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

Cytokinesis (Plant cells)

A
  • Cell wall prevents cleavage
  • Vesicles from the Golgi apparatus line up along the metaphase plate. Vesicles fuse with each other and the cell surface membrane dividing the cell into two.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Importance of mitosis

A
  • Growth and repair
  • Replace cells
  • Asexual reproduction
  • Maintain chromosome number in all cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Homologous chromosomes

A

Matching pair of chromosomes, one inherited from each parent

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

Allele

A

Different versions of the same gene

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

Locus

A

The position of a gene on a chromosome

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

Gamete

A

Sex cell

27
Q

Haploid

A

Half the number of chromosomes

28
Q

Diploid

A

Normal chromosome number
Two of each chromosome
46 chromosomes

29
Q

Significance of meiosis

A
  • Produces haploid cells

- Creates genetic variation through independent assortment and crossing over

30
Q

Independent assortment

A
  • Metaphase 1
  • Bivalents line up on equator independent of each other. Oriented randomly
  • Metaphase 2
  • Independent assortment of chromatids
31
Q

Crossing over

A
  • Prophase 1
  • Homologous chromosomes pair up bivalents form
  • Crossing over : Non-sister chromatids entangle
  • Alleles are exchanged
32
Q

Suggests the importance of the creation of different allele combinations in populations

A

Creating different allele pairs during meiosis is an important source of genetic variation. Genetic variation is important for the process of natural selection, giving individuals in a population characteristics that might be advantageous in changing environments. If there was no genetic variation the entire population would be vulnerable to an external factor

33
Q

Meiosis

A
  • Meiosis 1 : The first division is the reduction division when the pair of homologous chromosomes separate into two cells
  • Meiosis 2 : The pairs of chromatids are separated, forming two more cells. Four haploid cells are produced
34
Q

Prophase 1

A
  • Chromosomes condense, nuclear envelope and nucleolus disappear. Homologous chromosomes pair up forming bivalents.
  • Chromatids entangle (crossing over)
35
Q

Metaphase 1

A
  • Homologous chromosomes assemble along the metaphase plate

- The orientation of each chromosome is random and independent( independent assortment)

36
Q

Anaphase 1

A
  • Homologous chromosomes pulled to opposite poles
  • Sections of DNA which become entangled during crossing over, break off and rejoin. The point at which the chromatids break and rejoin are called chiasmata
  • When exchange occurs this forms recombinant chromatids
37
Q

Telophase 1

A
  • Nuclear membrane reforms
  • Chromosomes uncoil
  • Cell undergoes cytokines and divides into two cells
38
Q

Prophase 2

A
  • Chromosomes condense and become visible

- Nuclear envelope breaks down and spindle formation begins

39
Q

Metaphase 2

A
  • Individual chromosomes assemble on the metaphase plate.

- There is independent assortment again

40
Q

Anaphase 2

A
  • Chromatids are pulled to opposite poles
41
Q

Telophase 2

A
  • Chromosomes uncoil and form chromatin again
  • Nuclear envelope and nucleolus reform
  • Cytokinesis
  • Four haploid cells
42
Q

Why is reduction division necessary in the production of gametes?

A
  • Gametes are sex cells and two sex cells must combine to produce a diploid offspring
  • Therefore gametes must contain only half the number of chromosomes otherwise with each new generation the number of chromosomes would increase
43
Q

Erythrocytes

A
  • Flattened biconcave shape : Increases the SA:V ratio
  • Don’t have a nuclei : Increases space available for haemoglobin
  • Flexible : Squeeze through narrow capillaries
44
Q

Neutrophils

A
  • White blood cells
  • Multi-lobed nucleus : Makes it easier for them to squeeze through small gaps
  • Lysosomes : Cytoplasm contains many lysosomes to attack pathogens
  • Flexible : Can engulf pathogens
45
Q

Squamous epithelial cells

A
  • Along the respiratory tract

- Flat and thin : Rapid diffusion

46
Q

Ciliates epithelium

A
  • Hair-like structures(cilia) : Cilia on the surface move in a rhythmic manner. Moves mucus away from the lungs
  • Goblet cells: Release mucus to trap any unwanted particles
47
Q

Sperm cells

A
  • Male gametes
  • Flagellum : Move to the ovum
  • Many mitochondria : Supply energy to swim
  • Acrosome : Contains digestive enzymes, which are released to digest the protective layers around the ovum
48
Q

Palisade cells

A
  • Chloroplast: Absorb large amount of light for photosynthesis
  • Rectangular box shapes : Closely packed to form a continuous layer
  • Thin cell walls : Increases rate of diffusion
  • Large vacuole : Maintains turgor pressure
49
Q

Root hair cells

A
  • Long extensions(root hairs) : Increases the surface area and maximises the uptake of water and minerals
50
Q

Guard cells

A
  • Pairs of guard cells on the surface of leaves form the stomata.
  • Guard cells lose water and become less swollen, they change shape and the stoma closes to prevent further water loss
  • Cell wall thicker on one side, so the cell does not change shape symmetrically
51
Q

Specialised cell

A
  • Produced by differentiation

- Differentiation is when a cell becomes specialised to perform a particular function

52
Q

Tissues

A
  • A collection of differentiated cells that have a specialised function
53
Q

Organ

A

Collection of tissues that are adapted to perform a particular function

54
Q

Organ systems

A

Organs working together to carry out a major function

55
Q

Cartilage

A
  • Connective tissue
  • Protects and strengthens
  • Chondrocytes produce an extra cellular matrix of collagen fibres(strength) and elastin fibres (flexibility)
  • Prevents ends of bonds from rubbing together and causing damage
56
Q

Muscle

A
  • Muscle is a tissue that needs to be able to shorten in length in order to move bones.
  • 3 types of muscle :
  • > Skeletal(movement)
  • > Smooth (involuntary e.g. stomach lining)
  • > Cardiac (heart)
  • Made up of bundles of elongated cells called muscle fibres. A bundle of muscle fibres is called a fascicle.
57
Q

Xylem

A
  • Transports water and minerals up the stem
  • Xylem cells are dead and have no cytoplasm
  • Parenchyma cells fill gaps between the other cells
  • Lignin for support
  • Vessel elements, which are elongated dead cells. Transports the water, has a wide lumen.
58
Q

Phloem

A
  • Transports organic nutrients up and down the plants
  • Composed of sieve tube cells separated by perforated walls called sieve plates.
  • Sieve tube cells : Reduced cytoplasm, few organelles, end walls form sieve plates
  • Companion cells - help the sieve cells with their functions using ‘plasmodesmata’(these allow molecules to pass between cells).
59
Q

Stem cells

A

Undifferentiated cells

60
Q

Potency

A

A stem cell’s ability to differentiate into different cell types is called potency

61
Q

Totipotent

A
  • These stem cells can differentiate into any type of cell

- E.g. Fertilised egg

62
Q

Pluripotent

A
  • These stem cells can form all tissue types but not whole organisms.
63
Q

Multipotent

A
  • Can only form a range of cells within a certain type of tissue.
    E.g. Haematopoetic stem cells

Biology (15 decks)

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