SB1

Question 1

What is resolution

Answer 1

The distance between two points that can be seen as two points

Question 2

What is the formula for magnification

Answer 2

Eyepiece lens x Objective lens
or
Size of image ÷ real size of object

Question 3

How do you get from milli to micro to nano to pico

Answer 3

x by 1000 each time

Question 4

How do you get from pico to nano to micro to milli

Answer 4

÷ by 1000

Question 5

Differences and similarities between light and electron microscopes

Answer 5

• Used beam of electrons instead of light
• Electron microscopes provide a higher resolution
• Electron microscopes have a larger magnification
• Both use radiation
• Electron microscopes cannot use living organisms, light microscopes can
• Electron microscopes are expensive

Question 6

What is a eukaryotic cell

Answer 6

A cell with a nucleus

Question 7

What does the cell membrane do

Answer 7

Controls what leaves and enters

Question 8

What does cytoplasm do

Answer 8

Where most of the organelles are and where most of the cell’s activity occur

Question 9

What does the mitochondria do

Answer 9

It’s where aerobic respiration occurs

Question 10

What does the nucleus do

Answer 10

Control’s cell activity and contains chromosomes which contain DNA

Question 11

What do ribosomes do

Answer 11

They make new proteins for a cell

Question 12

What does the cell wall do

Answer 12

Supports and protects the plant cell

Question 13

What do chloroplasts do

Answer 13

They contain chlorophyll and traps energy from the sun, they also cause the leaf to be green

Question 14

What do vacuoles do

Answer 14

Stores cell sap which keeps the cell firm and rigid

Question 15

What do microvilli do

Answer 15

They’re tiny folds that increase the surface area of the intestine to allow more molecules to be absorbed

Question 16

What are enzymes

Answer 16

Biological catalysts made of proteins that speed up reactions without being used up

Question 17

How can cells be equipped with a lot of energy

Answer 17

They have a lot of mitochondria

Question 18

What is fertilisation

Answer 18

When a sperm and egg cell fuse to create a zygote

Question 19

List adaptations of an egg cell

Answer 19

• After fertilisation, the cell membrane becomes hard
• Cytoplasm is packed with nutrients to supply zygote with energy
• Haploid nucleus
• Jelly coat for protection, becomes hard after fertilisation

Question 20

List adaptations of a sperm cell

Answer 20

• Acrosome at the tip contains enzymes to break down substances in the egg cell
• Mitochondria arranged in a spiral around top of the tail to release lots of energy, powers the tail
• Tail to swim

Question 21

What are cilia used for

Answer 21

To sweep substances along

Question 22

What adaptations does an oviduct have

Answer 22

Ciliated epithelial cells to sweep substances along

Question 23

What does prokaryotic mean

Answer 23

A cell without nuclei

Question 24

What are plasmids

Answer 24

Small loops of DNA that controls cell activity

Question 25

Name two organelles of bacteria cells that animal cells never have

Answer 25

Cell wall- for support

Flagellum (not all bacteria have)

Question 26

What are proteins broken down into

Answer 26

Amino acids by digestion

Question 27

What is starch broken down into

Answer 27

Glucose molecules

Question 28

What are lipids broken down into

Answer 28

Fatty acids and glycerol

Question 29

Where are amylase found and what do they do

Answer 29

Found in the saliva and small intestine and catalyse the break down starch into sugars

Question 30

Where are catalase found and what do they catalyse

Answer 30

Liver cells (most cells also) and catalyse the break down hydrogen peroxide made in cell reactions

Question 31

Where is starch synthase found and what do they do

Answer 31

Plant cells and they catalyse the synthesis of starch from glucose

Question 32

Where are DNA polymerase found and what do they do

Answer 32

Found in the nucleus and they catalyse the synthesis of DNA from its monomers

Question 33

What does iodine do (testing foods)

Answer 33

Turns blue-black in the presence of starch (from yellow-orange)

Question 34

How does Benedict’s solution work

Answer 34

When a food solution is mixed with Benedict’s solution and placed in a hot water bath, the colour changes from blue to red, indicating a lot of sugar (blue -> green -> orange -> red)

Question 35

What happens in the biuret test

Answer 35

Potassium hydroxide is added to food solution
Two drops of copper sulfate added
Pale blue solution turns purple, indicating protein

Question 36

What happens in the ethanol emulsion test

Answer 36

Food is mixed with ethanol and shaken, fats and oils float to the surface and a cloudy emulsion is forced when the mixture is left to stand

Question 37

How can we measure the amount of energy in food

Answer 37

Burning it in a calorimeter

Question 38

What is the active site

Answer 38

Area on an enzyme where the desired substrate fits (different enzymes have certain shapes because every enzyme can only work with specific substrates)

Question 39

How can enzymes become denatured

Answer 39

By a change in pH or temperature, it can affect how the enzyme folds up.

Question 40

What is diffusion

Answer 40

Diffusion is the movement of a substance from an area of high concentration to an area of lower concentration

Question 41

What is osmosis

Answer 41

The movement of water molecules from a low to high concentration through a partially permeable membrane

Question 42

What is active transport

Answer 42

Active transport is the movement of dissolved molecules into or out of a cell through the cell membrane against a concentration gradient, low to high concentration (requires energy as it is an active process)

Question 43

How do you work out percentage change in mass

Answer 43

percentage change in mass = [ (final mass - initial mass) ÷ initial mass ] x100