KBTC International School Biology Mid-Year Exam Paper 2023 PDF

S2 KBTC International School Examination and Evaluation Board NAME ROLL NUMBER LEVEL Secondary - 2 BATCH NUMBER EXAM MID-YEAR BIOLOGY December 2023...

S2 KBTC International School Examination and Evaluation Board NAME ROLL NUMBER LEVEL Secondary - 2 BATCH NUMBER EXAM MID-YEAR BIOLOGY December 2023 1 hr 30 mins 50 Marks READ THESE INSTRUCTIONS FIRST. Write your answers in the space provided. Write in dark blue and black pen. You may use an HB pencil for any lines, diagrams or graphs. Do not use correction fluid. 100 ANSWER ALL QUESTIONS. Score This document consists of (9) pages.  SECTION A Questions 1 to 15 carry 1 mark each. For each question, the options are given. Choose the one that you consider correct and write its letter in the space provided. (15×1 = 15 marks) 1. The diagram shows one way the body defends itself against pathogens. What is the name of this defense mechanism? A. antibody production B. egestion C. vaccination D. phagocytosis 1.__________________ 2. The diagram shows part of an alveolus and part of a nearby capillary. The arrow shows the direction of movement of carbon dioxide and oxygen. By which process do these gases move? A. Conduction B. Diffusion C. Osmosis D. Radiation 2.__________________ 3. Which iconic desert plant is commonly found in the Sonoran Desert and known for its arms that extend upward? A. Teddy bear cholla B. Saguaro cactus C. Yucca plants D. Joshua tree 3.__________________ Secondary 2 KBTC International School  4. What is the primary concern associated with the use of DDT as an insecticide? A. Increase plant growth B. Improve water quality C. Have harmful effects on non-target species and ecosystems D. Kill mosquitoes and fleas 4.__________________ 5. The diagram shows a food chain for a pond. If a fisherman catches all the pike in the pond, which of the following would increase? A. tadpoles only B. perch only C. perch and tadpoles D. perch and pondweed 5.__________________ 6. Larynx contains ____________, they are the bands of muscles. A. Voice box B. Rubber band C. Vocal cord D. Cartilage 6.__________________ 7. What is the main role of decomposers in an ecosystem? A. They produce energy through photosynthesis B. They break down dead organisms and recycle nutrients C. They provide food for primary consumers D. They regulate the populations of other organisms 7.___________________ 8. Lions eat antelopes. Antelopes eat plants. A lion is eating an antelope. Which of these statements correctly describes what is taking place when a lion eats antelope? A. carnivore is eating its prey B. herbivore is eating its prey C. predator is eating a carnivore D. prey is eating a herbivore 8.__________________ Secondary 2 KBTC International School  9. What is a common pathway for the introduction of invasive species into new ecosystems? A. Natural migration B. Human activities C. Climate change D. Genetic mutations 9.___________________ 10. Which substances can be broken down by decomposers? A. Organic B. Inorganic C. Both A and B D. None of the above 10.__________________ 11. What is a good reason for conserving mangrove ecosystems? A. They allow the sea easy access to the land B. They form habitats for snakes C. They form habitats for young fish D. They grow at a very slow rate 11.__________________ 12. Which large predator can be found in the Arctic Ocean Ecosystem? A. A snow turtle B. Arctic hares C. Seal D. Arctic crab 12.__________________ 13. The colors on the ___________ show temperatures of different objects, A. Thermostat B. Thermometer C. Thermogram D. Thermogenesis 13.__________________ 14. Which component of the blood carries gas for respiration? 14.__________________ Secondary 2 KBTC International School  15. An ecosystem is defined as ____________. A. interaction between plants and animals B. interaction between living things and physical environment C. interaction between predators and preys D. None of these 15._________________ SECTION B Questions 16 to 20 carry 3 marks each. (5×3= 15 marks) 16. Complete the following sentences. (a) Some animals prefer to come out and search for food at night. Those animals are called n__________ animals. (b) The chemicals that cannot be broken down in nature or in the bodies of organisms are termed p__________ chemicals. (c) The arrows in the food chain show e_________ passing from one organism to another. 17. The diagram shows a food web in an aquatic ecosystem. (a) According to this food web, which organism is a producer? ______________________________________________________________________________ (b) According to this food web, name organisms which are herbivores. ______________________________________________________________________________ Secondary 2 KBTC International School  (c) Name carnivorous organisms in this food web. ______________________________________________________________________________ 18. Complete the following sentences with the appropriate words. When you breathe in, these things happen: The intercostal muscles between the ribs 1(contract/relax). This pulls the ribs upwards and outwards. The muscles in the diaphragm contract. This pulls the diaphragm 2(upwards/downwards). These two movements increase the volume inside the 3(chest/thorax). 1.________________ 2.________________ 3.________________ 19. Red blood cells carry oxygen to body cells for respiration. Give three reasons why red blood cells are good at carrying oxygen. ________________________________________________________________________________ ________________________________________________________________________________ ______________________________________________________________________________ 20. Coral reefs are formed by tiny animals called coral polyps. Their hard skeletons provide many different habitats where other species can live. One of these species is a single-celled alga that makes a toxic substance called ciguatoxin. Herbivorous fish eat alga. Carnivorous fish eat herbivorous fish. Humans often eat carnivorous fish. (a) Thousands of different species live on coral reefs. Use the information to suggest why so many species can live there. _________________________________________________________________________________ ______________________________________________________________________________ (b) What is meant by a toxic substance? ______________________________________________________________________________ Secondary 2 KBTC International School  (c) Use the information to construct a food chain. ______________________________________________________________________________ SECTION C Questions 21 to 24 carry 5 marks each. (5×4= 20 marks) 21. Choose the best words to complete the sentences. antibodies bacteria carbon dioxide cytoplasm glucose haemoglobin least like most nucleus oxygen plasma unlike Blood contains a pale-yellow liquid, called ____(a)_____. This liquid carries red blood cells and white cells around the body. It also transports several different substances in solution, including _____(b)______and _____(c) _____. Red blood cells are the _____(d)_____ abundant cells in the blood. Their function is to transport ______(e)_____from the lungs to all the cells in the body that are respiring. To help them to do this, they contain a red pigment called ______(f)_______. White blood cells, ______(g)_____red blood cells, contain a nucleus. Their function is to destroy pathogens, such as ______(h)______, that get into the body. Some of them do this by producing chemicals called _____(i)_______, which attach themselves to the pathogens and kill them. Other white blood cells kill pathogens by taking them into their _____(j)_____and digesting them. (a) ________________ (b) ________________ (c) ________________ (d) ________________ (e) ________________ (f) ________________ (g) ________________ (h) ________________ (i) ________________ (j) ________________ Secondary 2 KBTC International School  22. Brown tree snakes have caused big changes on the island of Guam. The diagram shows the food web presents before and after the arrival of the tree snakes. (a) State whether the numbers of the species listed below went up or down after brown tree snakes arrived in Guam and explain each answer. Species Up/Down Explanation Insect-eating birds Down They are eaten by the brown tree snake. Spiders Bats (b) How will the forest be affected if the insect population increases? ______________________________________________________________________________ Secondary 2 KBTC International School  23. DDT is a chemical that was used by farmers to control insect pests eating their crops. It can be used to demonstrate bioaccumulation as shown in this diagram. The concentration of DDT is shown in the diagram in parts per million (ppm). (a) What is DDT? ______________________________________________________________________________ (b) To the nearest whole number, how many times greater is the concentration of DDT in the birds of prey than in a sunfish? ______________________________________________________________________________ (c) Explain, in your own words, why the concentration in the blue heron is greater than in a sunfish. _________________________________________________________________________________ ______________________________________________________________________________ (d) What would happen to the blue heron as it accumulates DDT over its lifetime? ______________________________________________________________________________ Secondary 2 KBTC International School  24. The dodo became extinct in the 17th century. The dodo was a flightless bird which lived on the island of Mauritius. The dodos built their nests on the ground. Dodos had never met humans before humans arrived on the island. The dodos were not afraid of the humans. Humans brought new animals to the island, such as cats, dogs and rats. The humans removed most of the forest where the dodos lived to build new homes and to create farmland. (a) Write down two reasons why you think that the dodo became extinct. ________________________________________________________________________________ ______________________________________________________________________________ (b) Name three invasive species in this case. ______________________________________________________________________________ (c) Describe two characteristics that make an invasive species successful. _________________________________________________________________________________ ______________________________________________________________________________ Secondary 2 KBTC International School