Paper 1 Content

Question 1

Formula for magnification

Answer 1

Image size / object cell size

Question 2

How to convert micrometers to mm

Answer 2

1ym = 1x10*-6m
Covert ym to mm by dividing by 1000

Question 3

Differences between eukaryotic cells and prokaryotic cell

Answer 3

1: Eukaryotic cells has a nucleus, prokaryotic has plasmid (loop of DNA)

2: eukaryotic has a cell membrane

Question 4

Similarity & Difference between animal and plant cell

Answer 4

Plant: chlorophyll, cell wall, permanent vacuole

Both: ribosone, cytoplasm, mitochondria, nucleus, cell membrane

Question 5

Difference be

Question 6

4 steps of mitosis

Answer 6

1. Nucleus dissolves & genetic material is duplicated
2. Two sets of chromosomes move to different sides
3. Mirchibdria, ribosomes & other organelles are duplicated
4. The cell divides, producing two genetically identical diploid cells

Question 7

What is diffusion

Answer 7

Movement of particles from an area of high concentration to an area of low concentration

Question 8

What is osmosis?

Answer 8

Diffusion of water from low conc of water molecules to high conc of water molecules

Question 9

Osmosis practical

Answer 9

-Weigh and place identical cylinders from same vegetable in sugar solutions of varying concentrations
-After set tine, remove excess water & reweigh, calculate change in mass

Question 10

Formula for change in mass percentage

Answer 10

Final mass - initial mass / initial mass x100

Question 11

Enzymes of carbohydrates, starch, proteins, lipids

Answer 11

• carbohydrases break down carbohydrates into simple sugars
• amylase breaks down starch into glucose
• proteases break down proteins into amino acids
• lipases break down lipids into glycerol & fatty acids

Question 12

What are enzymes

Answer 12

Biological catalysts often breaking down molecules into shorter ones (polymers into monomers)

Question 13

Enzyme Key points

Answer 13

⚫️Enzymes are specific so only break down substrates that fit their active site (‘lock and key’ principle)
⚫️rate of reaction increases with temperature until the enzyme denatures (active site changes shape).

Optimum= condition for max rate/activity

Question 14

Enzyme Practical

Answer 14

• mix amylase with starch and start timer
• remove a few drops from mixture every 10 seconds and add to iodine
• record the time taken for no startch