biology

Question 1

What is the difference between animal and plant cells?

Answer 1

Animal cells have no cell wall or chloroplasts, plant cells do

Question 2

Label the main parts of a typical animal cell.

Answer 2

Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes

Question 3

What is the role of the nucleus?

Answer 3

The nucleus controls the cell and contains DNA

Question 4

Describe the function of chloroplasts in a plant cell.

Answer 4

Chloroplasts absorb light for photosynthesis

Question 5

What are the differences between prokaryotic and eukaryotic cells?

Answer 5

Prokaryotic cells have no nucleus or membrane bound organelles, eukaryotic cells do

Question 6

What is the formula for calculating magnification?

Answer 6

Magnification = image size ÷ actual size

Question 7

Describe how to prepare a slide of onion cells.

Answer 7

Peel onion layer, place on slide, add iodine, cover with cover slip

Question 8

Why do electron microscopes have higher resolution than light microscopes?

Answer 8

Electron microscopes use electrons (shorter wavelength), giving better resolution

Question 9

What happens during mitosis?

Answer 9

Mitosis is when a cell divides to make two identical cells for growth or repair

Question 10

Why is mitosis important in the human body?

Answer 10

Mitosis is needed for growth and repair

Question 11

What is the function of stem cells?

Answer 11

Stem cells can develop into different types of cells

Question 12

Give two sources of stem cells and explain one potential use in medicine.

Answer 12

Embryos and bone marrow, treat diseases like paralysis or diabetes

Question 13

Define diffusion.

Answer 13

Movement of particles from high to low concentration

Question 14

Name three substances that move by diffusion in the body.

Answer 14

Oxygen, carbon dioxide, glucose

Question 15

What is osmosis?

Answer 15

Osmosis is the movement of water through a partially permeable membrane from high water concentration to low water concentration.

Question 16

Describe what happens to a plant cell in a very salty solution.

Answer 16

The cell will shrink because water leaves the cell.

Question 17

What is active transport? Give one example.

Answer 17

Active transport moves substances from low to high concentration using energy (mineral ions into root cells)

Question 18

Name the major organs of the digestive system in order.

Answer 18

Mouth, oesophagus, stomach, small intestine, large intestine, rectum, anus

Question 19

What is the role of the small intestine?

Answer 19

The small intestine absorbs nutrients into the blood

Question 20

What enzyme breaks down starch, and where is it made?

Answer 20

Amylase. It’s made in the salivary glands, pancreas, and small intestine

Question 21

How do bile and hydrochloric acid help digestion?

Answer 21

Bile breaks up fats into smaller droplets and neutralises stomach acid

Question 22

What is the “lock and key” model of enzyme action?

Answer 22

the enzyme fits with its substrate like a key in a lock

Question 23

How does temperature affect enzyme activity?

Answer 23

Temperature increases enzyme activity to a point, then too much heat makes it stop working.

Question 24

What happens to enzymes at very high temperatures?

Answer 24

The enzyme becomes denatured – its shape changes and it can’t work anymore

Question 25

What are the functions of arteries veins, and capillaries?

Answer 25

Arteries carry blood away from the heart (thick walls), veins carry blood to the heart (have valves), capillaries are tiny and let substances pass in and out

Question 26

Describe the structure of the heart and how it pumps blood.

Answer 26

The heart pumps blood to the lungs to get oxygen, and around the body to deliver it

Question 27

What is the function of red blood cells?

Answer 27

Red blood cells carry oxygen using haemoglobin

Question 28

How do white blood cells help defend against pathogens?

Answer 28

They destroy pathogens by engulfing them or producing antibodies

Question 29

What is the function of platelets?

Answer 29

Platelets help the blood to clot at a wound

Question 30

What is the difference between communicable and non-communicable diseases?

Answer 30

Communicable = can spread like a cold, non-communicable = can’t spread like cancer

Question 31

Give two risk factors for coronary heart disease.

Answer 31

Smoking, not exercising, eating too much fat or sugar

Question 32

What is cancer and how do tumors form?

Answer 32

Cancer happens when cells divide out of control and make a tumour

Question 33

What are pathogens? Give examples of bacterial, viral, and fungal diseases.

Answer 33

Pathogens are microorganisms that cause disease, like bacteria (salmonella), viruses (measles), and fungi (athlete’s foot).

Question 34

How are diseases spread?

Answer 34

Through the air, like coughing, dirty water, or direct contact

Question 35

How can infection be reduced or prevented?

Answer 35

Washing hands, vaccinations, using disinfectants, or isolating sick people

Question 36

How does the skin protect against pathogens?

Answer 36

Skin stops pathogens getting in, it’s a barrier

Question 37

What is the role of mucus and cilia?

Answer 37

Mucus traps pathogens, and cilia move them out of the lungs

Question 38

What do white blood cells do to kill pathogens?

Answer 38

White blood cells kill pathogens by eating them or producing antibodies

Question 39

How do vaccines work?

Answer 39

Vaccines have a weak or dead form of the pathogen. They cause the body to make antibodies

Question 40

What is herd immunity?

Answer 40

If lots of people are vaccinated, the disease can’t spread easily, even to unvaccinated people

Question 41

What is an antibiotic?

Answer 41

Antibiotics kill bacteria

Question 42

Why is antibiotic resistance a growing problem?

Answer 42

If we overuse antibiotics, bacteria can mutate and become resistant, they won’t be killed anymore

Question 43

How are new drugs tested before use?

Answer 43

Drugs are tested in labs, on animals, and then in human trials to check they are safe and effective

Question 44

Write the word and symbol equation for photosynthesis.

Answer 44

word: Carbon dioxide + water (arrow) glucose + oxygen. symbol: Symbol: 6CO₂ + 6H₂O (arrow) C₆H₁₂O₆ + 6O₂

Question 45

What factors affect the rate of photosynthesis?

Answer 45

Light, temperature, and carbon dioxide all affect how fast photosynthesis happens

Question 46

Describe a practical to investigate the effect of light on photosynthesis.

Answer 46

Use pondweed in water. Shine a lamp at different distances and count the bubbles

Question 47

What is glucose used for in plants?

Answer 47

Plants use glucose for respiration, making cellulose, storing as starch, and making proteins and fats

Question 48

What is the word equation for aerobic respiration?

Answer 48

Glucose + oxygen (arrow) carbon dioxide + water

Question 49

What is the difference between aerobic and anaerobic respiration?

Answer 49

Aerobic needs oxygen, anaerobic doesn’t. Anaerobic makes less energy and produces lactic acid

Question 50

When does anaerobic respiration happen in humans?

Answer 50

When you exercise hard and don’t have enough oxygen

Question 51

Why does lactic acid build up during exercise?

Answer 51

Because the body switches to anaerobic respiration

Question 52

What is oxygen debt?

Answer 52

Oxygen debt is the extra oxygen needed to break down the lactic acid after exercise

Question 53

Why does your breathing rate stay high after you stop exercising?

Answer 53

To take in more oxygen so your body can get rid of the lactic acid and repay the oxygen debt

Question 54

How does the body remove lactic acid from the muscles?

Answer 54

The blood carries it to the liver where it is broken down using oxygen

Question 55

What waste product builds up in muscles during anaerobic respiration?

Answer 55

Lactic acid

Question 56

Explain why athletes might cool down by jogging slowly after intense exercise

Answer 56

It keeps the heart and breathing rate up, helping deliver more oxygen to the muscles to remove lactic acid faster

Question 57

Compare what happens in the body during aerobic and anaerobic respiration in terms of oxygen debt

Answer 57

Aerobic respiration uses oxygen and doesn’t make lactic acid, so there’s no oxygen debt. Anaerobic respiration doesn’t use oxygen and causes lactic acid to build up, creating an oxygen debt

Question 58

Why is oxygen debt larger after very intense exercise compared to light exercise?

Answer 58

Because more anaerobic respiration happens, making more lactic acid that needs more oxygen to break down

Question 59

what happens in the 3 stages of the cell cycle?

Answer 59

interphase - cell grows, dna replicates, new organelles mitosis - chromosomes pull to each side of cell cytokinesis - cell membrane + cytoplasm divide

Question 60

2 purposes of mitosis

Answer 60

growth and repair, asexual reproduction

Question 61

What happens to an enzyme when the temperature is too high?

Answer 61

can become denatured, meaning its shape changes so the substrate no longer fits in the active site. This stops it from working properly