Revision 1 Q1. Which of the following statements is true? A. A cell is the basic unit for animals only. B. A multicellular organism has more than one cell in its body. C. Plant cells and animal cells only differ in terms of cell wall. D. A unicellular organism does not need a nucleus to function. Plants and animals are examples of multicellular organisms. They contain millions of cells in their body. Q2. Which of the following characteristics is true for cell walls? A. They restrict the movement of substances across the cell. B. They support the cellular structure in animal cells from bursting when water enters the cell excessively. C. They are made up of cellulose that cannot be digested by animals easily. D. They are found in some animal cells. Extra: They are the fibres in our diets to help our bowel movement. 1
Q3. What is the name of the system that consists of brain and spinal cord in human beings? A. The reproductive system B. The digestive system C. The circulatory system D. The nervous system Nervous system 2
Q4. Which of the following organs are parts of the respiratory system? A. heart and blood vessels B. sperm duct and penis C. trachea and bronchi D. mouth and oesophagus Q5. Which of the following organelles are collectively called protoplasm? A. Chloroplast, nucleus, cell wall B. Cell wall, cell membrane, nucleus C. Nucleus, cell membrane, cytoplasm D. Cell wall, cell membrane, Protoplasm is the living contents of a cell that is surrounded by a plasma membrane. Cell wall is not part of the protoplasm. Animal has protoplasm but no cell wall. Q6. Which of the following organelles in a cell allows energy transformation from chemical energy to heat energy to take place? A. Nucleus B. Cytoplasm C. Chloroplast D. Cell membrane Cytoplasm is the site where chemical processes in the cell take place. 3
Q7. Which of the following terms correctly describes a group of organ systems that performs similar tasks in a systematic and coordinated manner? A. Organs B. Organ systems C. Organism D. Cells Structure Characteristics Examples Tissue A large number of similar cells performing a particular function Plants: Epidermal tissue, photosynthetic tissue, supporting tissue Animals: Epithelial tissue, muscle tissue, nerve tissue Organ System Two or more tissues grouped together, carrying out the same function. Two or more organs working together in the same function Heart (muscle, blood and connective tissues) Brain (nerve and connective tissues) Digestive, circulatory, nervous, respiratory, excretory, reproductive system Q8. Which of the following animals cannot control over their own body temperature? A. Chimpanzees B. Chameleons C. Hummingbirds D. Rodents Cold-blooded animals cannot control their body temperature. Chameleons are reptiles. Fish Amphibians Reptiles They are cold blooded and live in water. Their bodies are covered with slimy scales. They have gills for breathing. They have fins for swimming. They are cold blooded. They have moist skin which is not covered by scales or hair. They live on both land and water but always lay their eggs in water. They have four legs. They are cold blooded. They have leathery skin which is covered with dry scales. They always lay their eggs on land. Their eggs have soft shells 4
Birds They are warm blooded. Their bodies are covered with feathers. They have beaks (no teeth) for feeding. They lay eggs with hard shells Mammals They are warm blooded. Their bodies are covered with hair or fur. Mothers produce milk for their babies (suckle their young). Q9. The descriptions of a plant kingdom are as follows: I. Non-flowering II. Reproduce by seed Ill. Growth on land What could be this plant kingdom? A. Ferns B. Conifers C. Mosses D. Hibiscus Conifers reproduce by seeds. 5
Mosses Conifers Ferns 6
Q10. Which of the following characteristics can be observed in hibiscus and rose? A. Both reproduce by spores. B. Both do not have true roots. C. Both have stems and leaves. D. Both have spores in the capsules. Both are flowering plants. They have true roots, stems and leaves. Q11. Which of the following is one of the characteristics for conifers? A. They have needle-like leaves. B. They have spores under their leaves. C. They are flowering-plants. D. They do not have true roots. They also reproduce by seeds. Conifers leaves Q12. Which of the following organisms does not have true roots but makes its own food? A. Mushroom B. Moss C. Fungi D. Conifer They can carry out photosynthesis. Q13. Which of the following groups of animals are all vertebrates? A. Tiger, starfish, rabbit B. Monkey, rat, roundworm C. Zebra, dolphin, rat D. Ant, crab, starfish 7
Q14. Which of the following characteristics cannot be used to describe millipedes? A. Have no backbones B. Have more than three pairs of legs C. Have jointed legs D. Have soft and moist exoskeleton Millipedes have hard and dry exoskeleton Q15. An organism has the following characteristics. I. Breathe through lung II. Have hair III. Give birth to young Which of the following organisms fits the above characteristics? A. Crocodiles B. Salamanders C. Stingrays D. Giraffe Salamanders 8
Stingrays Q16. The diagram below shows an apparatus used to investigate osmosis. After a few hours, which changes in levels will occur and which substances will move across the membrane? Level M Level N Substance A. Fall Rise Starch B. Fall Rise Water C. Rise Fall Starch D. Rise Fall Water 9
Starch solution has a lower concentration of water, water will move across the Visking tubing into the starch solution. Q17. Which statement best explains why gases move across the stomata of green leaves during warm and sunny day? A. The gases gain energy which cause them to move more randomly and vigorously. B. The gases expand. As a result, they move out from the stomata to occupy more spaces. C. The gases are warmed. As a result, their densities decrease and they rise up D. The gases have different concentrations inside and outside of the leaves. Questions 18 and 19 refer to the diagram below. It shows a typical plant cell after being placed in a beaker of salt solution for 10 minutes. Q18. What could be the concentration of the salt solution in the beaker? A. 5% salt solution B. 15% salt solution C. 20% salt solution D. 25% salt solution The concentration of salt solution must be higher in the beaker than in the cell, so that water molecules move out from the cell. The diagram shows a plasmolysed plant cell. Q19. Which process is involved to cause this observation of the cell? A. Osmosis B. Diffusion C. Expansion D. Active transport 10
Osmosis is the movement of water molecules from the region of higher water concentration to a region of lower water concentration through a partially permeable membrane. Diffusion is the spreading out of one substance through another due to the random motion of particles. Q20. Which of the following is one of the functions of blood capillaries? A. Allow osmosis of oxygen B. Allow diffusion of glucose C Transport oxygen gas D. Transport plasma Blood capillaries allow exchange of substances between bloodstream and the living cells. Oxygen and useful nutrients move out from the bloodstream into the living cells. Waste products such carbon dioxide leave the living cells and enter the bloodstream. 11
Q21. Which statement best explains why red blood cells have biconcave shape? A. To transport more carbon dioxide B. To contain more cytoplasm C. To decrease its density D. To increase the rate of oxygen exchange Red blood cell has a biconcave disc shape to increase surface area to volume ratio for efficient transportation of oxygen. Q22. The diagram below shows part of a root hair cell. Which of the following will take place? A. Salt will move into the root hair cell from the soil through active transport. B. Osmosis of water will not take place. C. Cytoplasm of the cell will change in its volume. D. No passive movement of substances will take place between the soil and the root hair cell. Cytoplasm will decrease in its volume because water molecules move out from the cell into the surrounding by osmosis. Q23. Which of the following substances is not transported by plasma? A. Carbon dioxide B. Glucose C. Heat D. Oxygen Oxygen is transported by red hood cells. 12
Q24. The diagram below shows a simplified diagram of blood circulation in a mammal. Which blood vessels transports blood with the highest oxygen content? A. 1 and 2 B. 2 and 4 C. 1 and 3 D. 3 and 4 Q25. Which statement about the movement of substances across the living cells is not correct? A. The direction of the movement of one substance depends on the concentration of the other substance. B. No energy is required when a substance moves down its concentration gradient C. Active transport will take place when mineral salts become scarce in soil. D. Osmosis can only take place if cell membrane is present in the living cells The movement of one substance from one region to another depends on its own concentration gradient iii different regions. Q26. The diagram below shows a typical root hair cell. 13
Which substance does not moves across the cell membrane by simple diffusion during respiration? A. Oxygen B. Carbon dioxide C. Glucose D. Excess water This movement of water across the cell membrane is known as osmosis. Q27. An onion layer loses its mass after placing in a beaker of solution for a period of time. Which of the following is not possible to be the solution in the beaker? A. Pure distilled water B. Pure starch solution C. Pure glucose solution D. Pure mineral salt solution Pure distilled water has the highest concentration of water molecules, therefore, there will he net movement of water molecules into the onion cells to cause them to gain mass. Q28. The diagram below shows an experiment to investigate the movement of substances. Which of the following most likely will not happen to the respective regions 1, 2 and 3 at the end of the experiment? 14
A. Region 1 increases in volume. B. There are same numbers of glucose molecules in these three regions. C. Regions 2 and 3 have equal volume. D. Blue-black observed in region 3 when two drops of iodine is added to it. Starch cannot move across the partially permeable membrane. Q29. Which statement best explains why the muscular walls of veins is thinner than that of arteries? A. They carry deoxygenated blood. B. They carry smaller volume of blood. C. They carry less substance in blood. D. They carry blood that flows slower in the vessels. Blood flows with a lesser pressure in the veins, so the speed of the blood is slower. Therefore, it does not require a thicker wall to withstand the low pressure. Q30. The diagram below shows the effect of solution Y on a red blood cell after half an hour. Which statement is not correct from this observation? A. Solution Y contains a higher concentration of solute than in the red blood cell B. The cell membrane of this red blood cell eventually will break apart. C. The red blood cell is said to be dehydrated. D. The red blood decreases in its volume and becomes soft. 15
The red blood cell shrinks. The appearance of thin red blood cell indicates that it loses water by osmosis. Therefore, the cell membrane will not burst. Hypotonic solution means dilute solution or less concentrated solution Hypertonic solution means concentrated solution or solution with little water. 16
Q31. Which of the following is not one of the differences between a red blood cell and a white blood cell? A. Presence of haemoglobin B. Presence of nucleus C. Presence of cytoplasm D. Presence of chromosomes White blood cells and red blood cells both have cytoplasm. 17
Q32. The diagram below shows the structure found in a typical human cheek cell. Which statement about this structure is correct? A. They restrict the movement of any substances across it by their masses. B. Water is the only substance that its direction of movement depends on the presence of this structure. C. It only allows the substances to move from its region of higher concentration to its region of lower concentration. D. It is present in a typical plant cell but is made of cellulose Osmosis takes place. A partially permeable membrane does not prevent active transport of a substance. Q33. Which of the following movements of substances is not an example of diffusion in plants? A. Oxygen is given out to the surroundings through the stomata after photosynthesis. B. Mineral salts are taken in by root hair cells when they have a lower concentration in soil. C. Water vapour is lost from the leaves through stomata during a warm and sunny day. D. Food is transferred from the leaves to the various parts of the plant after photosynthesis. Active transport is a process when a substance moves from its region of low concentration to its region of high concentration against a concentration gradient. Energy is involved. 18
Q34. Which of the following components transport substances in the circulatory system? I. Plasma II. White blood cells Ill. Red blood cells A. I only B. Ill only C. I, II and Ill D. I and Ill White blood cells do not transport substances. They only fight against infections. Q35. Which of the following is not one of the differences between an artery and a vein? A. Compositions of blood B. The size of lumen C. Thickness of muscular wall D. Blood flow pressure Blood flow in both vessels contains the same compositions, i.e. plasma, red blood cells, white blood cells and platelets. Q36. The diagram below shows a section from the plant root after taken out from a red dye solution. Which structure most likely transports substance made in the green leaves? 19
D. This diagram shows the section from the root. The structure which is stained red is a xylem vessel because xylem vessels transport water containing the red dyes. Option D is phloem. Q37. The diagram below shows part of the human circulatory system. Which substance occurs at a higher concentration in the blood flow 1 than in the blood flow 2? A. Oxygen B. Carbon dioxide C. Nitrogen D. Glucose Blood floss from the lungs to the heart has the highest oxygen concentration after picking up fresh oxygen front the atmosphere. Q38. Which of the following blood vessels most likely contains the highest concentration of dissolved oxygen in the blood vessels? A. Pulmonary artery B. Pulmonary vein C. Aorta D. Renal artery Pulmonary vein receives fresh oxygen from the lungs. 20
Q39. The diagrams show three types of blood vessels, 1, 2 and 3. Which of the following describes the characteristics for each type of vessel? Blood flow under high pressure Location of exchange of substances Blood flow controlled by valves A. 1 2 3 B. 3 1 2 C. 2 3 1 D. 1 3 2 Arteries Veins Capillaries Function carry blood away from the heart Structure Thick, elastic and muscular wall carry blood towards the heart Thin, less elastic and less muscular wall 21 allow exchange of substances between blood and the body cells One-cell thick to allow substances can diffuse to and from the cells Valves Absent Present Absent Blood flow Very fast as blood is under high pressure In spurts Slow as under low pressure Smooth flow Slow as under low pressure
Size of lumen Small Large Very narrow Q40. Which of the following is the correct pathway for blood circulation in human? A. Right atrium left atrium left ventricle lungs right ventricle B. Lungs left atrium left ventricle right ventricle right atrium C. Left ventricle right atrium right ventricle lungs left atrium D. Lungs left ventricle left atrium right ventricle right atrium 22
Q41. A plant was placed in jar as shown below. The condition was suitable for the plant to make food, as there was sunlight and the soil was moist. The air inside the jar contained carbon dioxide gas which is made up of radioactive carbon element. The carbon from the gas was incorporated into food during photosynthesis. After two hours, the plant was removed from the jar. The stem was cut crosssectional. It was then placed on photographic film which became black when exposed to radioactivity. Which diagram shows the correct positions of the black spots found on the film? A. The black spots should only be observed in phloem tissues as they transport food substances. 23
Q42. The diagram below shows a human heart and its attached vessels. Which of the following correctly describes the conditions of the blood in the different vessels? A B C D P Q R S Oxygenated, high pressure Deoxygenated, high pressure Deoxygenated, low pressure Oxygenated, high pressure Deoxygenated, low pressure Deoxygenated, low pressure Deoxygenated, low pressure Deoxygenated, high pressure Deoxygenated, high pressure Oxygenated, high pressure Oxygenated, high pressure Deoxygenated, low pressure Oxygenated, high pressure Oxygenated, high pressure Oxygenated, high pressure Deoxygenated, low pressure 24
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Q43. The diagram below shows part of the human alimentary canal What is the function of X? A. To remove solid waste from the body B. To absorb water into body C. To take in mineral salts into the body D. To store solid waste temporarily It is a rectum. Q44. Which of the following is not one of the end products of digestion in the small intestine? A. Fatty acids B. Short protein chains C. Glycerol D. Glucose Proteins are broken down into short protein chains in the stomach. In the small intestine, they are further digested into amino acids. Q45. Which of the substances is taken into the bloodstream when it reaches the large intestine? A. Vitamins B. Glucose C. Amino acids D. Fatty acids and glycerol Large intestine absorbs mineral salts, vitamins and water. Note that no chemical digestion takes place in large intestine. 26
Q46. The diagram below shows part of the human alimentary canal. What would happen when part P is removed? A. Digestion of fats becomes slower B. No production of bile in the digestive system C. No secretion of lipase D. No secretion of hydrochloric acid Bile breaks up fats into droplets to increase its total surface area so that lipase can digest them at a faster rate. Bile is produced by the liver. Structure P is bile duct. The bile secreted by the liver passes through a Y-shaped duct, as shown in Figure. The bile travels down one branch of the Y shaped duct and then up the other branch to the gallbladder, a saclike organ that stores and concentrates bile. 27
Q47. Which chemical digestion takes places in the beginning of the human alimentary canal? A. Complex protein molecules are broken down into smaller protein molecules. B. Large and complex food is broken into smaller pieces by the action of chewing. C. Food is pushed down into the stomach by a long muscular tube. D. Large and complex starch in food is broken down into maltose. Starch is digested first in the mouth by salivary amylase. Salivary amylase is released by the salivary glands. Q48. Which of the following statements about starch and glucose is correct? A. They both contain the constituent elements of carbon, hydrogen and oxygen only. B. Starch can provide twice the amount of energy than glucose in a same amount of mass. C. Starch gives blue--black colour with iodine after mixed with salivary amylase. D. Glucose is the first carbohydrate that is broken down in the mouth of the human alimentary canal. Glucose and starch are carbohydrates. Fats are also made up of elements carbon, hydrogen and oxygen only. 28
Q49. The diagram below shows the movement of substances in a muscular tube. Which of the following regions in the human alimentary canal can this movement be found? I. Oesophagus II. Mouth III. Large intestine A. I only B. II only C. I and Ill D. II and Ill As you can see in Figure, alternating contractions of these muscle layers push the bolus through the esophagus and into the stomach. This series of rhythmic muscular contractions and relaxations is called peristalsis. Peristalsis is so efficient at moving materials down the esophagus that you can drink while standing on your head. The smooth muscles move the water up the esophagus, against the force of gravity. 29
Q50. Which of the following does not secrete enzymes in the human alimentary canal? A. The liver B. The small intestine C. The pancreas D. The stomach Liver secretes bile. Q51. The diagram below shows part of the human alimentary canal. Which statement about structure P is not correct? A. It is part of the human alimentary canal which carries out chemical digestion of food B. Digestion of fatty food substances can only be carried out from the secretion of P. C. Protease from structure P digests the smaller protein molecules into amino acids. D. Maltase secreted by structure P completes the digestion of starch into glucose. P is pancreas. It is an organ associated to alimentary canal but it is not part of it. It does not carry out chemical digestion. Chemical digestion is carried out in the small intestine. 30
Q52. The diagram below shows part of the human alimentary canal. Which of the following actions does not take place in structure M? A. Killing bacteria in food B. Breaking down proteins chemically C. Absorption of amino acids D. Churning action on the digested food Absorption of simpler food molecules only takes place in the small intestine. Q53. Which statement best explains why fibres are not taken into the bloodstream in the small intestine? A. Fibres are too heavy to move through the wall of the small intestine. B. Fibres do not have any useful functions in our body, so they are not being absorbed. C. Fibres are not able to move across the partially permeable membrane present in the wall of the small intestine. D. Fibres cannot move against its concentration gradient from the lumen of the small intestine into the bloodstream. 31
Q54. The diagram below shows the human alimentary canal. Which regions show the enzyme activities? A. 1 and 4 B. 1, 3 and 5 C. 2, 3 and 5 D. 1, 2 and 4 32
The Human Digestive System. Food breaks down as it moves through the chambers of the digestive tract. Accessory organs aid in digestion. 33