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1. Tema: Cell biology

   1. Which organelle is the site of aerobic respiration?

   ANucleusBRibosomeCMitochondrionDChloroplast
   Solución

   C. Mitochondrion

   • Aerobic respiration releases energy from glucose using oxygen.
   • It takes place in the mitochondria, often called the powerhouse of the cell.

2. Tema: Excretion

   2. The functional unit of the kidney is the

   AneuronBnephronCalveolusDvillus
   Solución

   B. nephron

   • Each kidney contains about a million nephrons.
   • Nephrons filter the blood and form urine.

3. Tema: Circulation

   3. Which blood vessel carries oxygenated blood from the lungs to the heart?

   APulmonary arteryBPulmonary veinCAortaDVena cava
   Solución

   B. Pulmonary vein

   • The pulmonary vein carries oxygenated blood from the lungs to the left atrium.
   • It is the only vein that carries oxygenated blood.

4. Tema: Plant nutrition

   4. The process by which green plants manufacture food using light energy is

   ArespirationBtranspirationCphotosynthesisDosmosis
   Solución

   C. photosynthesis

   • Photosynthesis uses light, carbon dioxide and water to make glucose.
   • Oxygen is released as a by-product.

5. Tema: Disease

   5. The vector of the malaria parasite is the

   AhouseflyBtsetse flyCfemale Anopheles mosquitoDmale Culex mosquito
   Solución

   C. female Anopheles mosquito

   • Malaria is caused by Plasmodium.
   • It is transmitted by the bite of the female Anopheles mosquito.

6. Tema: Nutrition

   6. A deficiency of vitamin C causes

   AricketsBscurvyCberiberiDnight blindness
   Solución

   B. scurvy

   • Vitamin C deficiency causes scurvy: bleeding gums and slow wound healing.
   • Rickets is vitamin D, beriberi is vitamin B1, night blindness is vitamin A.

7. Tema: Ecology

   7. In the food chain grass, grasshopper, lizard, hawk, the lizard is a

   AproducerBprimary consumerCsecondary consumerDdecomposer
   Solución

   C. secondary consumer

   • Grass is the producer and the grasshopper is the primary consumer.
   • The lizard eats the primary consumer, so it is the secondary consumer.

8. Tema: Reproduction in plants

   8. Which part of a flower develops into the fruit after fertilisation?

   AOvuleBOvaryCPetalDAnther
   Solución

   B. Ovary

   • After fertilisation, the ovary becomes the fruit.
   • The ovules inside it become the seeds.

9. Tema: Digestion

   9. The enzyme in saliva that begins the digestion of starch is

   ApepsinBlipaseCsalivary amylaseDtrypsin
   Solución

   C. salivary amylase

   • Salivary amylase (ptyalin) breaks starch into maltose in the mouth.
   • Pepsin digests protein in the stomach; lipase digests fats.

10. Tema: Genetics

    10. Two heterozygous tall plants (Tt) are crossed. What is the expected ratio of tall to dwarf offspring?

    A1 : 1B1 : 3C3 : 1Dall tall
    Solución

    C. 3 : 1

    • Possible offspring: TT, Tt, Tt and tt.
    • T is dominant, so TT and Tt are tall: 3 tall to 1 dwarf.