B1 - Cell Structure and Transport

Question 1

equation for magnification

Answer 1

magnification = image size / real size

Question 2

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

Answer 2

1000μm = 1mm

Question 3

What are the two categories of microscope?

Answer 3

Optical (light) and Electron

Question 4

How do optical microscopes produce an image?

Answer 4

Lenses inside a microscope magnify an image

Question 5

What is the maximum magnification of an optical microscope?

Answer 5

2000x

Question 6

define resolution

Answer 6

The minimum distance between 2 distinct points on an image

Question 7

What is the purpose of staining cells?

Answer 7

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

Question 8

What are two different dyes used when staining cells?

Answer 8

• iodine solution
• methylene blue

Question 9

How do electron microscopes produce an image?

Answer 9

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

Question 10

What is the possible magnification of an electron microscope?

Answer 10

1,000,000x

Question 11

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

Answer 11

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

Question 12

What are the 4 disadvantages of using an electron microscope?

Answer 12

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

Question 13

What is a cell?

Answer 13

A cell is the simplest unit of a living thing.

Question 14

What are the structures in living cells?

8

Answer 14

• Nucleus
• Ribosome
• Cell wall
• Cell membrane
• Cytoplasm
• Mitochondria
• Chloroplast
• Permanent vacuole

Question 15

features of a prokaryotic cell (5)

Answer 15

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

Question 16

What are 2 advantages of electron microscopes?

Answer 16

• high magnification
• high resolution

Question 17

What are organelles?

Answer 17

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

Question 18

features of an eukaryotic cell

Answer 18

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

Question 19

define differentiation

Answer 19

Differentiation is the process when a cell changes

Question 20

define specialisation

Answer 20

Specialisation is what a cell changes into after differentiation

Question 21

define diffusion

Answer 21

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).

Question 22

When do molecules stop diffusing?

Answer 22

Molecules diffuse until equilibrium is reached.

Question 23

What factors affect the speed of diffusion?

Answer 23

• the difference in concentration
• distance molecules have to travel
• temperature

Question 24

define solute

Answer 24

a substance that is dissolved in a solution

Question 25

define solvent

Answer 25

a substance that can dissolve another substance

Question 26

define solution

Answer 26

a solute dissolved in a solvent

Question 27

What does a partially permeable membrane allow?

Answer 27

It allows small molecules to pass through

Question 28

define osmosis

Answer 28

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

Question 29

how do particles move

Answer 29

particles move randomly | brownian motion

Question 30

explain lysis

Answer 30

when an animal cell swells up and bursts

Question 31

define crenation

Answer 31

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

Question 32

explain turgidity in a plant cell

Answer 32

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

Question 33

explain plasmolysis

Answer 33

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.

Question 34

define hypotonic solution

Answer 34

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

Question 35

define hypertonic solution

Answer 35

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

Question 36

define isotonic solution

Answer 36

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

Question 37

when does incipient plasmolysis occur

Answer 37

when a solution becomes isotonic

Question 38

equation % change

Answer 38

% change = (change / original value) x 100

Question 39

how many decimetres in a metre

Answer 39

10dm in 1m

Question 40

how many litres in a decimetre³

Answer 40

1litre in 1dm³

Question 41

define active transport

Answer 41

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

Question 42

define independent variable

Answer 42

the variable in an experiment that is being changed

Question 43

define dependent variable

Answer 43

the variable in an experiment that is measured

Question 44

define control variable

Answer 44

the variable in an experiment that does not change

Question 45

what is the function of the nucleus? | in a cell

Answer 45

stores genetic material (DNA)

Question 46

What is the function of the ribosomes?

Answer 46

produce proteins

Question 47

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

Answer 47

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

Question 48

What is the function of the cell membrane?

Answer 48

controls what enters and leaves the cell

Question 49

What is the function of the cytoplasm?

Answer 49

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

Question 50

What is the function of the mitochondria?

Answer 50

to produce energy through aerobic respiration

Question 51

What is the function of the chloroplasts?

Answer 51

contains chlorophyll and is also the site of photosynthesis

Question 52

What is the function of the permanent vacuole?

Answer 52

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

Question 53

word equation for photosynthesis

Answer 53

carbon dioxide + water → glucose + oxygen

Question 54

chemical equation for photosynthesis

Answer 54

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Question 55

equation for concentration

Answer 55

concentration = mass / volume

Question 56

What substances are moved by diffusion?

Answer 56

gases and liquids

Question 57

What substance is moved in osmosis?

Answer 57

water

Question 58

What substances are moved by active transport? | in a plant

Answer 58

mineral ions

Question 59

Examples of specialised cells

Answer 59

- red blood cell - sperm cell - nerve cell (neuron) - root hair cell - leaf cell

Question 60

What is a stem cell?

Answer 60

A stem cell is a cell that is not specialised.

Question 61

What is a passive process?

Answer 61

It is a process that does not require energy

Question 62

What is a specialised cell?

Answer 62

A cell that performs a specific task

Question 63

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

Answer 63

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

Question 64

What is a cell?

Answer 64

A cell is the simplist unit of a living thing

Question 65

optical microscope diagram

Answer 65