1.1

Question 1

Using units

1kilometre=
1m=
1cm=
1mm=
1um=

Answer 1

1kilometre= 1000metres (m)
1m= 100 centimetres (cm)
1cm=10milimetres (mm)
1mm=100micrometres (um)
1um=1000 nanometres (nm)

Question 2

whats a light microscope

Answer 2

A microscope that uses visible light and lenses

Question 3

What are the key features of a light microscope?

Answer 3

Stage, objective lens, eye piece lens, focus adjustment, light source

Question 4

What is an electron microscope?

Answer 4

A microscope that uses electrons and electron lenses

Question 5

What is magnification?

Answer 5

How many times bigger than it actually is

Question 6

What is resolution?

Answer 6

Minimum distance apart that two objects can be in order for them to be seen as separate objects

Question 7

What are the advantages of using an electron microscope compared to a light microscope?

Answer 7

Higher magnification and resolution

Question 8

How is magnification calculated?

Answer 8

magnification = image size / actual size

Question 9

Where are chromosomes found in an animal cell

Answer 9

nucleus

Question 10

Describe the DNA in a bacteria cell

Answer 10

A single DNA loop or a DNA ring (plasmid)

Question 11

what is the function of cytoplasm

Answer 11

the water-based gel in which organelles of all living cells are suspended
-where chemical reactions take place

Question 12

whats the function of a cell membrane

Answer 12

-to control the passage of substances e.g glucose and mineral ions into the cell
-also controls the movement of substances e.g urea or hormones out the cell

Question 13

whats the function of mitochondria

Answer 13

where aerobic respiration takes place, releasing energy for the cell

Question 14

whats the function of ribosomes

Answer 14

where protein synthesis takes place
—making all the proteins needed in the cell

Question 15

List the five parts of an animal cell

Answer 15

Nucleus, Cytoplasm, Cell membrane, Mitochondria, Ribosomes

Question 16

List the three parts of a cell only found in plant cells

Answer 16

Vacuole (filled with cell sap), Chloroplasts, Cell wall

Question 17

What is a cell wall made of in a plant cell?

Answer 17

cellulose

Question 18

What function does cellulose have in a cell wall?

Answer 18

Provides strength

Question 19

Name three specialised animal cells

Answer 19

Sperm, Nerve, Muscle

Question 20

Name three specialised plant cells

Answer 20

Xylem, Root hair, Phloem

Question 21

What is cell differentiation?

Answer 21

When different types of cells are formed in an organism

Question 22

State two benefits of an electron microscope over a light microscope

Answer 22

Greater resolving power, Higher magnification

Question 23

What is a stem cell?

Answer 23

An undifferentiated cell

Question 24

What is diffusion?

Answer 24

Spreading out of particles of a substance in solution or a gas

Question 25

What process moves substances into and out of a cell across a cell membrane?

Answer 25

Diffusion

Question 26

What does diffusion result in?

Answer 26

The net movement of particles from an area of higher concentration to an area of lower concentration

Question 27

Name two substances transported in and out of cells during gas exchange

Answer 27

Oxygen, Carbon Dioxide

Question 28

Name three factors that affect diffusion

Answer 28

-Difference in concentration (concentration gradient), -Temperature -Surface area of membrane

Question 29

How does water move across cell membranes?

Answer 29

by osmosis

Question 30

What is osmosis?

Answer 30

Diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane

Question 31

What is active transport?

Answer 31

The movement of substances from a more dilute solution to a more concentrated solution

Question 32

What's the role of active transport in plants?

Answer 32

The absorption of mineral ions from dilute solutions in soil via root hairs

Question 33

What's the role of active transport in humans?

Answer 33

Allows sugar molecules to move from the gut into the blood

Question 34

name two ways embryonic stem cells can cure diseases

Answer 34

-producing insulin -replacing neurons

Question 35

give the two main differences between active transport and diffusion

Answer 35

diffusion doesn't require energy and AT does -diffusion moves molecules from a high to low con AT goes low to high