I85PREP
⌘ K
BGCSE Human & Social Biology study materials
BGCSE Human & Social Biology study resources

BGCSE Human & Social Biology practice questions

One question at a time. Build your BGCSE Human & Social Biology understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Cells and Life Processes

Which structure controls the activities of a eukaryotic cell and contains the genetic material?

  1. The ribosome
  2. The nucleus Correct answer.
  3. The Golgi apparatus
  4. The cell membrane

Explanation

The nucleus encloses the chromosomes, which are made of DNA, and it directs protein synthesis and cell division by regulating gene expression. Other organelles carry out specific tasks but do not hold the main genetic instructions.

Question 2Cells and Life Processes

A student views a cell and observes a rigid outer layer outside the cell membrane. Which type of cell is most likely being observed?

  1. A plant cell Correct answer.
  2. A nerve cell
  3. An animal cell
  4. A red blood cell

Explanation

Plant cells have a cellulose cell wall outside the plasma membrane, giving shape and support. Animal cells such as red blood cells and nerve cells lack a cell wall and are bounded only by a flexible membrane.

Question 3Cells and Life Processes

Which process moves water molecules across a partially permeable membrane from a region of higher water concentration to one of lower water concentration?

  1. Active transport
  2. Phagocytosis
  3. Osmosis Correct answer.
  4. Hydrolysis

Explanation

Osmosis is the diffusion of water through a partially permeable membrane down a water potential gradient. It requires no energy and occurs only for water, distinguishing it from active transport and bulk uptake processes.

Question 4Cells and Life Processes

Which molecule is the main immediate source of energy for cellular processes?

  1. Glucose
  2. Cellulose
  3. ATP Correct answer.
  4. Haemoglobin

Explanation

ATP releases energy rapidly when its terminal phosphate bond is hydrolysed, so it is the direct energy currency used by cells. Glucose stores energy but must first be broken down through respiration to make ATP.

Question 5Cells and Life Processes

Which gas is released by a green plant during photosynthesis?

  1. Methane
  2. Carbon dioxide
  3. Oxygen Correct answer.
  4. Nitrogen

Explanation

During photosynthesis, chlorophyll traps light energy and splits water, releasing oxygen as a by-product while carbon dioxide is fixed into glucose. The released oxygen comes from water, not from carbon dioxide.

Question 6Cells and Life Processes

Which enzyme acts on starch, breaking it down into simpler sugars?

  1. Catalase
  2. Amylase Correct answer.
  3. Lipase
  4. Protease

Explanation

Each enzyme is specific to its substrate. Amylase catalyses the hydrolysis of starch into maltose and other sugars, whereas lipase and protease act on fats and proteins respectively.

Question 7Cells and Life Processes

Which feature of a red blood cell increases its capacity to transport oxygen?

  1. It lacks a nucleus, leaving more room for haemoglobin Correct answer.
  2. It contains many chloroplasts
  3. It has a large nucleus that stores oxygen
  4. It has a thick cellulose wall

Explanation

Mature red blood cells lose their nucleus, so the space inside is filled with haemoglobin, the oxygen-carrying pigment. A biconcave shape also increases surface area, but the absence of a nucleus is the key internal adaptation.

Question 8Cells and Life Processes

Which statement describes diffusion?

  1. Large particles are engulfed by the cell membrane
  2. Water is forced through a membrane by pressure
  3. Particles move from lower to higher concentration using energy from ATP
  4. Particles spread from a region of higher concentration to a region of lower concentration Correct answer.

Explanation

Diffusion is the passive net movement of particles down a concentration gradient, driven by random motion. It needs no ATP and applies to gases and dissolved substances in cells.

Question 9Cells and Life Processes

An onion cell is placed in pure water. Which change is expected?

  1. The cell bursts immediately because it has no wall
  2. The cell becomes turgid because water enters the vacuole Correct answer.
  3. The cell becomes flaccid because water leaves the vacuole
  4. The cell shrinks because the cytoplasm is lost

Explanation

Pure water has a higher water potential than the cell sap, so water enters by osmosis and the vacuole swells, pressing the cytoplasm against the cell wall. The rigid wall resists further expansion, making the cell turgid rather than bursting.

Question 10Cells and Life Processes

Which statement best explains why an enzyme is described as having a specific active site?

  1. The active site changes shape permanently after each reaction
  2. Enzymes work only at very high temperatures
  3. Only substrates with a complementary shape can bind to the enzyme Correct answer.
  4. Any molecule can bind because the active site is flexible and unshaped

Explanation

The active site has a shape complementary to a particular substrate, so only that substrate can form an enzyme-substrate complex. This lock-and-key or induced-fit specificity explains why each enzyme catalyses one type of reaction.

Question 11Cells and Life Processes

A reaction catalysed by an enzyme is fastest at 37 degrees Celsius and slows sharply above 45 degrees Celsius. What is the best explanation for the slowdown?

  1. The enzyme's active site is denatured and no longer fits the substrate Correct answer.
  2. The reaction has become endothermic
  3. The substrate concentration has increased
  4. The enzyme is used up in the reaction

Explanation

Above the optimum temperature, increased vibration disrupts the bonds holding the enzyme's three-dimensional shape, so the active site loses its complementary fit. The enzyme is denatured and the rate of enzyme-substrate complex formation falls.

Question 12Cells and Life Processes

Which part of a leaf is adapted to maximise light absorption for photosynthesis?

  1. The spongy mesophyll, which has large air spaces
  2. The xylem, which transports water
  3. The palisade mesophyll, which has many chloroplasts near the upper surface Correct answer.
  4. The lower epidermis, which has a waxy cuticle

Explanation

Palisade cells are packed with chloroplasts and lie just below the upper epidermis, close to the light source. Their columnar arrangement and high chloroplast density increase light absorption for photosynthesis.

Question 13Cells and Life Processes

Which statement correctly describes the role of chlorophyll in photosynthesis?

  1. It absorbs carbon dioxide from the air
  2. It transports water from the roots to the leaves
  3. It absorbs light energy and transfers it to drive the reactions of photosynthesis Correct answer.
  4. It converts glucose into starch for storage

Explanation

Chlorophyll is a pigment in chloroplasts that absorbs mainly red and blue light and passes the energy into the light-dependent reactions. Carbon dioxide uptake, storage conversion and water transport are carried out by other structures.

Question 14Cells and Life Processes

A plant is kept in darkness for two days. Which immediate effect on photosynthesis is expected?

  1. The light-dependent reactions stop, so less ATP and reduced NADP are produced Correct answer.
  2. The plant begins to respire for the first time
  3. Chlorophyll is converted into glucose
  4. Carbon dioxide uptake stops completely because stomata close permanently

Explanation

Without light, chlorophyll cannot be excited, so the light-dependent stage stops and the supply of ATP and reduced NADP falls. The light-independent stage then slows because it depends on these products.

Question 15Cells and Life Processes

Which sequence correctly describes the path of blood through the mammalian heart?

  1. Right atrium, left atrium, lungs, right ventricle, left ventricle
  2. Right atrium, right ventricle, lungs, left atrium, left ventricle Correct answer.
  3. Left atrium, left ventricle, lungs, right atrium, right ventricle
  4. Left ventricle, right ventricle, lungs, left atrium, right atrium

Explanation

Deoxygenated blood enters the right atrium, passes to the right ventricle and is pumped to the lungs. Oxygenated blood returns to the left atrium and is pumped by the left ventricle to the body.

Question 16Cells and Life Processes

Which blood vessel has the thickest muscular and elastic wall relative to its lumen?

  1. Vein
  2. Lymph vessel
  3. Capillary
  4. Artery Correct answer.

Explanation

Arteries carry blood at high pressure, so they have thick muscular and elastic walls to withstand and smooth the pressure surges from the heart. Veins have thinner walls and wider lumens, while capillaries have walls only one cell thick.

Question 17Cells and Life Processes

Which change occurs in the breathing system during vigorous exercise?

  1. The diaphragm relaxes permanently
  2. The alveoli close to reduce gas exchange
  3. Breathing rate decreases to conserve oxygen
  4. Breathing rate and depth increase to remove more carbon dioxide Correct answer.

Explanation

During exercise, respiring muscles produce more carbon dioxide, which raises blood acidity and stimulates the breathing centre. Ventilation rate and depth increase to remove carbon dioxide and take in more oxygen.

Question 18Cells and Life Processes

Which feature of alveoli makes gas exchange efficient?

  1. A small surface area to reduce diffusion distance
  2. A layer of cartilage surrounding each air sac
  3. A large total surface area with thin walls and a rich blood supply Correct answer.
  4. A thick, moist lining that traps air

Explanation

Millions of alveoli provide a very large surface area, and their walls are one cell thick with capillaries close by, giving a short diffusion path. Ventilation and blood flow maintain steep concentration gradients for oxygen and carbon dioxide.

Question 19Cells and Life Processes

Which product of digestion is absorbed into the lacteals of the villi?

  1. Fatty acids and glycerol Correct answer.
  2. Mineral ions
  3. Glucose
  4. Amino acids

Explanation

Fatty acids and glycerol are recombined into fats and enter the lacteals, which are lymphatic vessels in the villi. Amino acids, glucose and mineral ions are water-soluble and are absorbed into the blood capillaries.

Question 20Cells and Life Processes

A person produces very little insulin. Which immediate effect on blood glucose is expected?

  1. Blood glucose falls because the liver releases more glucose
  2. Blood glucose is unaffected because insulin has no role in glucose control
  3. Blood glucose remains high because cells take up less glucose Correct answer.
  4. Blood glucose falls rapidly because cells take up more glucose

Explanation

Insulin stimulates cells, especially liver and muscle cells, to take up glucose and store it as glycogen. Without enough insulin, glucose stays in the blood, producing high blood glucose concentrations.

Question 21Cells and Life Processes

Which statement correctly describes the role of the loop of Henle in the kidney?

  1. It secretes urea into the filtrate
  2. It creates a concentration gradient in the medulla so water can be reabsorbed Correct answer.
  3. It filters blood under pressure to form urine
  4. It reabsorbs all glucose from the filtrate

Explanation

The loop of Henle establishes a high solute concentration in the medulla by countercurrent multiplication, so water can be reabsorbed osmotically from the collecting duct. This concentrates the urine and conserves water.

Question 22Cells and Life Processes

A cell is placed in a solution whose solute concentration is higher than that of its cytoplasm. What happens to an animal cell in this solution?

  1. It stays the same size because the membrane is impermeable
  2. It takes in solutes by active transport and swells
  3. It gains water by osmosis and swells
  4. It loses water by osmosis and shrinks Correct answer.

Explanation

The surrounding solution has a lower water potential than the cytoplasm, so water leaves the cell through the partially permeable membrane. The animal cell has no wall to resist shrinkage, so it loses volume and may become crenated.

Question 23Cells and Life Processes

Which combination of factors would most increase the rate of diffusion of oxygen into a respiring cell?

  1. A low temperature and a thick cell wall
  2. A shallow concentration gradient and a thick membrane
  3. A steep concentration gradient and a short diffusion distance Correct answer.
  4. A small surface area and a long diffusion distance

Explanation

Fick's principle states that the rate of diffusion is proportional to the concentration gradient and surface area and inversely proportional to the distance. A steep gradient and a thin barrier with a short path therefore maximise the rate.

Question 24Cells and Life Processes

Which statement best explains why the light-independent reactions of photosynthesis stop soon after light is removed?

  1. They are inhibited by the presence of glucose in the stroma
  2. They depend on ATP and reduced NADP supplied by the light-dependent reactions Correct answer.
  3. They need oxygen as a substrate for carbon fixation
  4. They require chlorophyll to absorb carbon dioxide directly

Explanation

The light-independent reactions use ATP and reduced NADP to reduce carbon dioxide into carbohydrate. Without light, the light-dependent stage stops making these products, so carbon fixation cannot continue for long.

Question 25Cells and Life Processes

In an experiment, a dialysis bag containing starch solution is placed in water and left for several hours. Iodine is then added to the water outside the bag. Which result is expected?

  1. The water outside turns blue-black because starch molecules diffused out of the bag Correct answer.
  2. The water inside the bag turns blue-black because water entered the bag
  3. The water outside turns blue-black because starch was broken down into glucose
  4. The water outside remains yellow-brown because starch molecules are too large to pass through the membrane

Explanation

Starch molecules are large and cannot pass through the pores of a dialysis membrane, so they remain inside the bag. Iodine solution turns blue-black in the presence of starch, so the outside water stays yellow-brown.

Question 26Cells and Life Processes

Which structure controls the movement of substances into and out of a cell?

  1. The nucleus
  2. The mitochondrion
  3. The cell membrane Correct answer.
  4. The vacuole

Explanation

The cell membrane forms the outer boundary of the cytoplasm and is partially permeable, so it regulates which substances enter and leave. The nucleus, mitochondria and vacuole lie inside the cell and carry out other functions rather than controlling exchange with the surroundings.

Question 27Cells and Life Processes

A student views a prepared slide using a microscope with a x10 eyepiece and a x40 objective lens. What is the total magnification?

  1. x50
  2. x30
  3. x4
  4. x400 Correct answer.

Explanation

Total magnification is found by multiplying the magnification of the eyepiece by that of the objective lens. Here 10 multiplied by 40 gives 400, so the image appears 400 times larger than the specimen.

Question 28Cells and Life Processes

Which process allows a white blood cell to engulf and digest a bacterium?

  1. Phagocytosis Correct answer.
  2. Active transport
  3. Osmosis
  4. Plasmolysis

Explanation

Phagocytosis is the process in which the cell membrane surrounds a particle and pinches inward to form a vesicle, which is then digested by enzymes. It is a form of endocytosis and requires energy from respiration, unlike osmosis, which is the passive movement of water.

Question 29Cells and Life Processes

A plant cell and an animal cell are both placed in a concentrated sugar solution. Which pair of observations is expected?

  1. The plant cell becomes flaccid and the animal cell shrinks. Correct answer.
  2. The plant cell becomes flaccid and the animal cell swells.
  3. The plant cell bursts and the animal cell shrinks.
  4. The plant cell becomes turgid and the animal cell swells.

Explanation

The surrounding solution has a lower water potential than the cytoplasm, so water leaves both cells by osmosis. In the plant cell the vacuole shrinks and the cytoplasm pulls away from the wall, making it flaccid, while the animal cell, lacking a wall, shrinks and becomes crenated.

Question 30Cells and Life Processes

A cell is treated with a substance that blocks the action of ribosomes. Which immediate consequence is expected?

  1. The cell can no longer copy its DNA before division.
  2. ATP production by the mitochondria stops at once.
  3. New protein molecules are no longer assembled. Correct answer.
  4. Waste products accumulate because lysosomes fail.

Explanation

Ribosomes are the site of protein synthesis, where amino acids are joined in the order coded by messenger RNA. Blocking them prevents the assembly of new proteins, although existing enzymes and stored ATP allow other processes to continue for a time.

Question 31Nutrition and Digestion

Which nutrient is the body's main quick source of energy and is found in foods such as bread, rice and potatoes?

  1. Protein
  2. Vitamin C
  3. Calcium
  4. Carbohydrate Correct answer.

Explanation

Carbohydrates are broken down into glucose, which cells use first for respiration and energy release. Starchy foods like bread, rice and potatoes are rich in carbohydrate, so they supply energy quickly.

Question 32Nutrition and Digestion

A student eats a meal containing butter, cooking oil and fatty meat. Which nutrient is present in the largest amount?

  1. Fat Correct answer.
  2. Iron
  3. Protein
  4. Dietary fibre

Explanation

Butter, cooking oil and fatty meat are all rich sources of fat, which the body uses for energy storage, insulation and protection of organs. The question asks which nutrient is most abundant in these foods, and it is fat.

Question 33Nutrition and Digestion

Which food group is the best source of dietary fibre?

  1. Cheese
  2. Wholegrain cereals Correct answer.
  3. Fresh fruit juice
  4. White bread

Explanation

Dietary fibre is plant material that cannot be digested, and wholegrain cereals keep the outer grain layers that are rich in fibre. Fibre adds bulk to food, helping the muscles of the gut push it along and preventing constipation.

Question 34Nutrition and Digestion

Which vitamin is produced in the skin when it is exposed to sunlight?

  1. Vitamin D Correct answer.
  2. Vitamin B
  3. Vitamin A
  4. Vitamin C

Explanation

Ultraviolet light in sunlight converts a substance in the skin into vitamin D, which helps the body absorb calcium for strong bones. People with little sun exposure may need vitamin D from foods or supplements.

Question 35Nutrition and Digestion

Which mineral is needed to make haemoglobin in red blood cells?

  1. Iron Correct answer.
  2. Sodium
  3. Potassium
  4. Iodine

Explanation

Iron is a component of haemoglobin, the red pigment that carries oxygen around the body. A diet low in iron can lead to anaemia, with tiredness and pale skin as common symptoms.

Question 36Nutrition and Digestion

Which part of the digestive system produces bile?

  1. Small intestine
  2. Pancreas
  3. Stomach
  4. Liver Correct answer.

Explanation

The liver produces bile, which is stored in the gall bladder and released into the small intestine. Bile helps to break large fat droplets into smaller ones so that fat-digesting enzymes can work faster.

Question 37Nutrition and Digestion

What is the main function of the teeth called incisors?

  1. Cutting and biting food Correct answer.
  2. Tearing tough food
  3. Grinding food
  4. Producing saliva

Explanation

Incisors are the flat, chisel-shaped front teeth used for cutting and biting off pieces of food. Their shape suits this job, while other teeth are shaped for tearing or grinding.

Question 38Nutrition and Digestion

Which process moves digested food molecules from the small intestine into the blood?

  1. Assimilation
  2. Ingestion
  3. Absorption Correct answer.
  4. Egestion

Explanation

Absorption is the movement of digested nutrients through the wall of the small intestine into the bloodstream. The villi lining the small intestine give a large surface area that makes absorption efficient.

Question 39Nutrition and Digestion

A person's diet lacks vitamin C over a long period. Which condition is most likely to develop?

  1. Goitre
  2. Rickets
  3. Scurvy Correct answer.
  4. Night blindness

Explanation

Vitamin C is needed to make the protein that holds skin and blood vessels together, so a long-term shortage causes scurvy. Symptoms include bleeding gums, slow-healing wounds and bruising.

Question 40Nutrition and Digestion

Enzymes in the mouth begin the digestion of which nutrient?

  1. Starch Correct answer.
  2. Protein
  3. Fat
  4. Vitamin C

Explanation

Saliva contains amylase, an enzyme that breaks starch down into simpler sugars such as maltose. This is why starchy foods begin to taste sweet if they are chewed for a long time.

Question 41Nutrition and Digestion

What is the main role of hydrochloric acid in the stomach?

  1. It absorbs glucose into the blood
  2. It makes bile in the liver
  3. It breaks fat into fatty acids and glycerol
  4. It kills bacteria and provides the acidic conditions pepsin needs Correct answer.

Explanation

Hydrochloric acid makes the stomach contents strongly acidic, which kills many swallowed bacteria and provides the low pH that pepsin requires to work. Without this acidity, protein digestion in the stomach would be very slow.

Question 42Nutrition and Digestion

Which feature of the small intestine increases the surface area for absorbing digested food?

  1. Presence of hydrochloric acid
  2. Thick muscular wall
  3. Large number of villi Correct answer.
  4. Storage of bile

Explanation

The inner lining of the small intestine is folded into millions of tiny finger-like villi, each with a rich blood supply. This greatly increases the surface area over which digested nutrients can be absorbed.

Question 43Nutrition and Digestion

Why is a diet high in dietary fibre recommended to prevent constipation?

  1. Fibre is digested into sugars that soften the faeces
  2. Fibre kills bacteria in the large intestine
  3. Fibre adds bulk that stimulates the gut muscles to push food along Correct answer.
  4. Fibre is absorbed as water in the stomach

Explanation

Fibre cannot be digested, so it remains in the gut and adds bulk to the contents. This bulk stimulates the muscular walls of the intestine to contract and move waste along, preventing constipation.

Question 44Nutrition and Digestion

Which statement best describes the importance of water in the diet?

  1. It provides most of the body's energy needs
  2. It is used to build muscle tissue
  3. It is needed for chemical reactions and to dissolve and transport substances Correct answer.
  4. It supplies the body with vitamins

Explanation

Water is the solvent in which most body reactions occur, and it carries nutrients and waste around the body in blood and urine. It also helps control body temperature through sweating.

Question 45Nutrition and Digestion

A boy of growing age needs plenty of protein. Which combination of foods would best supply high-quality protein?

  1. Oranges and carrots
  2. Beans and lentils
  3. Rice and cooking oil
  4. Fish and eggs Correct answer.

Explanation

Fish and eggs are animal foods that provide protein containing all the essential amino acids needed for growth and repair. Combining such foods supports the rapid tissue building of a growing child.

Question 46Nutrition and Digestion

Which of these describes the action of bile on fats?

  1. It absorbs fat directly into the liver
  2. It chemically digests fat into glycerol and fatty acids
  3. It converts fat into glucose for energy
  4. It emulsifies fat into smaller droplets to increase enzyme action Correct answer.

Explanation

Bile is not an enzyme; it physically breaks large fat droplets into many smaller ones, a process called emulsification. This increases the surface area on which lipase can act, speeding up fat digestion.

Question 47Nutrition and Digestion

Which sequence correctly shows the path of food through the digestive system?

  1. Mouth, oesophagus, stomach, small intestine, large intestine Correct answer.
  2. Mouth, stomach, oesophagus, large intestine, small intestine
  3. Mouth, oesophagus, small intestine, stomach, large intestine
  4. Mouth, stomach, small intestine, oesophagus, large intestine

Explanation

Food is chewed in the mouth, swallowed down the oesophagus, then enters the stomach before passing into the small intestine and finally the large intestine. This order matches the organs that carry out digestion and absorption.

Question 48Nutrition and Digestion

A person has a blocked bile duct, so bile cannot reach the small intestine. Which digestive process would be most affected?

  1. Digestion of protein into amino acids
  2. Digestion of fat into fatty acids and glycerol Correct answer.
  3. Digestion of starch into sugars
  4. Absorption of water in the large intestine

Explanation

Bile emulsifies fats, increasing the surface area for lipase to break them down. If bile cannot reach the small intestine, fat digestion becomes much less efficient, though the other processes continue largely normally.

Question 49Nutrition and Digestion

Which of these is a good source of vitamin A, needed for healthy eyesight?

  1. Table salt
  2. White sugar
  3. Carrots Correct answer.
  4. Cooking oil

Explanation

Carrots contain a substance that the body converts into vitamin A, which is needed to make a pigment in the retina for vision in dim light. A shortage of vitamin A can lead to night blindness.

Question 50Nutrition and Digestion

Which statement explains why people with a diet lacking both calcium and vitamin D may develop rickets?

  1. Vitamin D helps the body absorb calcium, and both are needed to harden bones Correct answer.
  2. Vitamin D is converted into calcium in the stomach
  3. Calcium destroys vitamin D in the body
  4. Calcium prevents vitamin D from entering the blood

Explanation

Vitamin D is needed for the efficient absorption of calcium from the intestine, and calcium is the mineral that hardens bone. A shortage of either means bones do not harden properly, causing the soft, bent bones of rickets.