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AQA GCSE Biology > B1 - Cell Structure and Transport > Flashcards

B1 - Cell Structure and Transport Flashcards

1
Q

equation for magnification

A

magnification = image size / real size

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2
Q

How many micrometres (μm) in a millimetre (mm)?

A

1000μm = 1mm

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3
Q

What are the two categories of microscope?

A

Optical (light) and Electron

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4
Q

How do optical microscopes produce an image?

A

Lenses inside a microscope magnify an image

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5
Q

What is the maximum magnification of an optical microscope?

A

2000x

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6
Q

define resolution

A

The minimum distance between 2 distinct points on an image

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7
Q

What is the purpose of staining cells?

A

A technique that is used to enhance a specimen on a microscopic level using a dye.

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8
Q

What are two different dyes used when staining cells?

A
  • iodine solution
  • methylene blue
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9
Q

How do electron microscopes produce an image?

A

A beam of electrons is shot through a sample in a vacuum chamber which uses the wave-live properties to magnify an image.

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10
Q

What is the possible magnification of an electron microscope?

A

1,000,000x

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11
Q

What is the difference between a scanning electron microscope and an electron microscope?

A

A scanning electron microscope produces images that are in 3D, while an electron microscope produces images in 2D.

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12
Q

What are the 4 disadvantages of using an electron microscope?

A
  • large
  • expensive
  • samples are dead because of the thin metallic coating applied
  • not portable
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13
Q

What is a cell?

A

A cell is the simplest unit of a living thing.

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14
Q

What are the structures in living cells?

8

A
  • Nucleus
  • Ribosome
  • Cell wall
  • Cell membrane
  • Cytoplasm
  • Mitochondria
  • Chloroplast
  • Permanent vacuole
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15
Q

features of a prokaryotic cell (5)

A
  • simple and small
  • 0.2μm - 2.0μm
  • genetic material in a plasmid (strand)
  • only organelles are ribosomes
  • binary fission cell division
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16
Q

What are 2 advantages of electron microscopes?

A
  • high magnification
  • high resolution
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17
Q

What are organelles?

A

Organelles are subcellular structures with one or more specific jobs in the cell. e.g. not cytoplasm

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18
Q

features of an eukaryotic cell

A
  • complex and large
  • 5μm - 100μm
  • genetic material in a membrane, nucleus
  • mitosis cell division
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19
Q

define differentiation

A

Differentiation is the process when a cell changes

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20
Q

define specialisation

A

Specialisation is what a cell changes into after differentiation

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21
Q

define diffusion

A

Diffusion is a passive process where molecules move from an area of high concentration to an area of low concentration (moving down the concentration gradient).

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22
Q

When do molecules stop diffusing?

A

Molecules diffuse until equilibrium is reached.

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23
Q

What factors affect the speed of diffusion?

A
  • the difference in concentration
  • distance molecules have to travel
  • temperature
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24
Q

define solute

A

a substance that is dissolved in a solution

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25
Q

define solvent

A

a substance that can dissolve another substance

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26
Q

define solution

A

a solute dissolved in a solvent

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27
Q

What does a partially permeable membrane allow?

A

It allows small molecules to pass through

28
Q

define osmosis

A

osmosis is the movement of water down a concentration gradient through a partially permeable membrane

29
Q

how do particles move

A

particles move randomly

brownian motion

30
Q

explain lysis

A

when an animal cell swells up and bursts

31
Q

define crenation

A

the loss of water in an animal cell that causes it to shrink

32
Q

explain turgidity in a plant cell

A

high concentration of water outside the cell causes turgidity, however, the cell does not increase in size because of the cell wall

33
Q

explain plasmolysis

A

low concentration of water outside the cell causes the cell to shrink, however, the cell wall does not shrink it only collapses after the cell dies.

34
Q

define hypotonic solution

A

a solution that has a greater concentration of water outside the cell than inside the cell

35
Q

define hypertonic solution

A

a solution that has a lower concentration of water outside the cell than inside the cell

36
Q

define isotonic solution

A

a solution that has the same concentration of water as inside the cell

37
Q

when does incipient plasmolysis occur

A

when a solution becomes isotonic

38
Q

equation % change

A

% change = (change / original value) x 100

39
Q

how many decimetres in a metre

A

10dm in 1m

40
Q

how many litres in a decimetre3

A

1litre in 1dm3

41
Q

define active transport

A

The movement of particles up a concentration gradient requiring energy produced from respiration.

42
Q

define independent variable

A

the variable in an experiment that is being changed

43
Q

define dependent variable

A

the variable in an experiment that is measured

44
Q

define control variable

A

the variable in an experiment that does not change

45
Q

what is the function of the nucleus?

in a cell

A

stores genetic material (DNA)

46
Q

What is the function of the ribosomes?

A

produce proteins

47
Q

What is the function of the cell wall? What is it made of?

A

keeps plant cells rigid and holds up the plant - it is made of cellulose

48
Q

What is the function of the cell membrane?

A

controls what enters and leaves the cell

49
Q

What is the function of the cytoplasm?

A

it holds the components of the cell and protects them from damage, it is also where chemical reactions take place

50
Q

What is the function of the mitochondria?

A

to produce energy through aerobic respiration

51
Q

What is the function of the chloroplasts?

A

contains chlorophyll and is also the site of photosynthesis

52
Q

What is the function of the permanent vacuole?

A

filled with sap to keep cell turgid and also where waste is stored

53
Q

word equation for photosynthesis

A

carbon dioxide + water → glucose + oxygen

54
Q

chemical equation for photosynthesis

A

6CO2 + 6H2O → C6H12O6 + 6O2

55
Q

equation for concentration

A

concentration = mass / volume

56
Q

What substances are moved by diffusion?

A

gases and liquids

57
Q

What substance is moved in osmosis?

58
Q

What substances are moved by active transport?

in a plant

A

mineral ions

59
Q

Examples of specialised cells

A
  • red blood cell
  • sperm cell
  • nerve cell (neuron)
  • root hair cell
  • leaf cell
60
Q

What is a stem cell?

A

A stem cell is a cell that is not specialised.

61
Q

What is a passive process?

A

It is a process that does not require energy

62
Q

What is a specialised cell?

A

A cell that performs a specific task

63
Q

Describe how these cells are adapted:
1. sperm cell
2. muscle cell
3. root hair cell
4. nerve cell (neuron)
7. red blood cell

A
  1. flagellum (tail) to facilitate movement
  2. more mitochondria for energy
  3. large surface area to increase the rate of diffusion
  4. long axon (fibre) to connect to neurons far away in the body
  5. no nucleus to allow more space for haemoglobin
64
Q

What is a cell?

A

A cell is the simplist unit of a living thing

65
Q

optical microscope diagram

AQA GCSE Biology (10 decks)

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