IGCSE Sciences - Co-Ordinated (0973) — October–November 2024, Paper 21

Which life process is the ability of an organism to detect and respond to changes in the environment?\nA growth\nB movement\nC nutrition\nD sensitivity

Which cells line the bronchi and bronchioles of the gas exchange system?\nA alveolar cells\nB ciliated epithelial cells\nC goblet cells\nD red blood cells

Which biological molecule contains the elements carbon, hydrogen, nitrogen and oxygen?\nA carbohydrate\nB fat\nC lipid\nD protein

The graph shows the effect of temperature on an enzyme-catalysed reaction rate. Which statements about the graph are correct?\n1 The optimum temperature is 37 °C.\n2 Above the…

Photosynthesis takes place in the mesophyll cells of a leaf. In which structure labelled A does photosynthesis occur?\nA chloroplast\nB cell wall\nC mitochondrion\nD…

Fig. 1 shows a villus from the small intestine. P and Q are structures in the villus. Which row correctly identifies structures P and Q and the substances they absorb?\nA P =…

Under which conditions is transpiration fastest?\nA cold and humid\nB cold and dry\nC warm and dry\nD warm and humid

A student breathes in and out through apparatus that shows which air has higher CO₂ content. Limewater in bottle P is connected to the mouth. Limewater in bottle Q is connected to…

What is accommodation?\nA the ability of the eye to focus on objects at different distances\nB the ability of the eye to detect different colours\nC the ability of the ear to…

Which statement is a similarity between asexual and sexual reproduction?\nA Both require two parents.\nB Both produce offspring with genetic information from the parent(s).\nC…

A pedigree shows the inheritance of coat colour in cattle over three generations. Heterozygous cattle have mixed coat colour. How many cattle in generation 3 are heterozygous?\nA…

Which statement is an example of an ecosystem?\nA a decomposing log with all the organisms living in and around it\nB a field containing only grass\nC a pond containing only water…

Which processes change the concentration of CO₂ in the air?\n1 combustion\n2 photosynthesis\n3 respiration\n4 transpiration\nA 1, 2 and 3 only\nB 1, 2 and 4 only\nC 1, 3 and 4…

A student distils sea water. Which changes should be made to the apparatus to improve the yield of distilled water?\nA Cool the condenser with warm water; collect in an open…

Which piece of apparatus cannot be used to measure the volume of a gas?\nA a burette\nB a gas syringe\nC a pipette\nD an inverted measuring cylinder over water

Which property is typical of a covalent compound?\nA low electrical conductivity when dissolved in water\nB high melting point\nC conducts electricity when molten\nD reacts…

What is the formula of ammonium phosphate?\nA (NH₄)₃PO₄\nB NH₄H₂PO₄\nC (NH₄)₂HPO₄\nD NH₄PO₄

Which statement about electrolysis is correct?\nA Electrolysis only works with solutions, not molten compounds.\nB Electrolysis requires an alternating current.\nC Electrolysis…

A match burns when struck. Which row correctly classifies this change?\nA physical change; endothermic\nB chemical change; exothermic\nC physical change; exothermic\nD chemical…

Which factors cause the rate of a reaction to increase at higher temperatures?\n1 Particles have greater energy.\n2 Particles collide more frequently.\n3 More particles have…

Which method is most suitable to prepare a pure, dry sample of barium sulfate?\nA Add barium hydroxide to sulfuric acid; filter and dry the precipitate.\nB Add barium oxide to…

Which electronic structure represents a non-metallic element in its ground state with 2 electrons in its outer shell?\nA 2\nB 2, 2\nC 2, 6\nD 2, 8, 2

Tennessine (Ts) is in Group VII. It is predicted that tennessine is a solid at room temperature. Which row shows the appearance of tennessine at room temperature and its reaction…

Which statement about the extraction of metals is correct?\nA Copper is extracted from its ore by electrolysis.\nB Gold is extracted from its ore by reduction with carbon.\nC Iron…

Which reagent is used to test for water?\nA anhydrous calcium chloride — turns blue if water is present\nB blue cobalt(II) chloride paper — turns pink if water is present\nC…

What is the general formula for unsaturated hydrocarbons in the alkene homologous series?\nA CₙH₂ₙ₋₂\nB CₙH₂ₙ₊₂\nC CₙH₂ₙ\nD CₙH₂ₙ₊₁

Which statement about poly(ethene) and nylon is correct?\nA Both are addition polymers.\nB Poly(ethene) is an addition polymer; nylon is a condensation polymer.\nC Both are…

A metal block has dimensions 25 cm × 5 cm × 8 cm and a mass of 2700 g. What is the density of the metal?\nA 2.7 g/cm³\nB 27 g/cm³\nC 270 g/cm³\nD 2700/(25×5×8) g/cm³

A spring has a natural length of 25 cm. Masses are added and the length measured. Between which loads is the limit of proportionality reached?\nA between 0 and 31 cm\nB between 31…

Two children sit on a see-saw. Child 1 has a weight of 300 N and sits 1.5 m from the pivot. Child 2 sits 1.4 m from the pivot. What is the weight of child 2 for the see-saw to…

Which energy resources use the Sun as their only original energy input?\nA coal, oil, solar\nB hydroelectric, nuclear, wind\nC natural gas, solar, wind\nD geothermal, solar,…

Substance X does not flow and has a fixed shape. Which state of matter is substance X?\nA gas\nB liquid\nC plasma\nD solid

A ray of light travels from glass to air at an angle less than the critical angle. What happens to the ray?\nA The ray bends towards the normal and its speed decreases.\nB The ray…

How do gamma rays compare to microwaves?\nA Gamma rays have a lower frequency and the same speed.\nB Gamma rays have a greater frequency and the same speed.\nC Gamma rays have a…

Which material makes the best core for an electromagnet?\nA soft iron, because it is easy to magnetise and demagnetise\nB steel, because it is hard to demagnetise\nC copper,…

A wire has a resistance of 4.0 Ω. A second wire of the same material has the same length but twice the cross-sectional area. What is the resistance of the second wire?\nA 2.0 Ω\nB…

In a circuit, a current I₁ enters a junction and currents I₂ and I₃ leave the junction. Which equation is correct?\nA I₁ = I₂ − I₃\nB I₁ = I₂ × I₃\nC I₂ = I₁ + I₃\nD I₁ = I₂ + I₃

An appliance is connected to the mains using a cable. The cable is fitted with a 3 A fuse but should have a 13 A fuse. What happens when the appliance is switched on?\nA The…

A transformer has 2000 turns on the primary coil and 100 turns on the secondary coil. The primary current is 1.0 A. What is the secondary current?\nA 0.05 A\nB 1.0 A\nC 50 A\nD…

Uranium-238 decays to thorium-234 by emitting an alpha particle. Thorium-234 then decays. Which emissions does thorium-234 produce?\nA alpha then beta\nB beta only\nC beta then…