BIOLOGY
PAPER 1
TERM 2 OPENER EXAM
INSTRUCTIONS
- Answer all the questions in this paper
- State two ways in which the rough endoplasmic reticulum is adapted to its function.(2mks)
- State three characteristics that are used to divide phylum arthropoda into classes.(3mks)
- Distinguish between diffusion and active transport.(2mks)
- An organism was found to have the dental formula:
I 1, C 0 , PM 3 , M 4
1 0 2 4- Calculate the total number of teeth in the organism.(1mk)
- Giving a reason suggest the mode of feeding of the organism.(2mks)
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- Give a reason for the biconcave shape of the red blood cells.(Imk
- Name the enzyme that speeds up loading of carbon (iv) oxide in the red blood cells.(1mk)
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- Name the vitamin, an enzyme and a mineral element that are involved in blood clotting.(1½mks)
- Vitamin
- Enzyme;
- Mineral element
- Differenciate between heparin and histamine (2mks)
- Name the vitamin, an enzyme and a mineral element that are involved in blood clotting.(1½mks)
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- Name the part of the brain that influences breathing rate.(Imk)
- State two advantages of breathing through the nostrils instead of through the mouth in mammals.(2mks).
- The diagram below resents a cell organelle.
- Name the main product of the organelle's activity (1½mk)
- Name the parts labeled A,B, C and D. (2mks)
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- State the cause of diabetes mellitus.(1mk)
- How may the disease in (9)(a) above be tested in a School laboratory?(2mks)
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- Distinguish between ecological niche and habitat (2mks)
- State two reasons why plants are included in a fish pond other than provision of food (2mks)
- State the functions of the following parts of a light microscope.
- Diaphragm (1mk)
- Objective lenses.(1mk)
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- Define the term respiratory quotient.(1mk)
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- After respiration of a certain substrate 50cm of carbon (iv) oxide was produced and 70cm Oxygen was used.Calculate the respiratory quotient of the substrate.(1 mk)
- Name the substrate in (12) (c) above. (1mk)
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- If a person who lives at low attitude moves to a higher attitude, changes occurring his blood consumption. Name two of these changes.(2mks)
- State the importance of these changes.(Imk)
- How are leaves of submerged plants adapted for photosynthesis? (2mks)
- Name the causative agents of the diseases below:
- Anthrax (Imk)
- Gonorrhea (Imk)
- Whooping cough(1mk)
- Explain why plants in waterlogged soils dry up.(3mks)
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- Name the antigens that determine human blood groups(2mks)
- Explain why people who have blood group AB are called universal recipients.(2mks)
- Name three processes in the human body in which homeostasis is involved.(3mks)
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- How are root hairs adapted to their function?(2mks)
- Name the process by which food is transported in plants.(Imk)
- State the significance of the following adaptations in a leaf.
- Thinness (Imk)
- Presence of airspaces(1 mk)
- Stomata (1mk)
- Study the food web below representing a certain ecosystem and use it to answer the questions that follow.
- State the trophic level occupied by the lion in the food web.(1 mk)
- Write down a food chain in which the vulture is a tertiary consumer(1mk)
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- Name the organism with the largest biomass(1 mk)
- Give two reasons for your answer in (c)(i) above.(2mks)
- Explain how temperature affects an enzyme controlled reaction (3mks)
- The diagram below represents a certain plant.
- What is the likely habitat of the plant?(1mk)
- Give two reasons for your answer in (a) above.(2mks)
- What is the likely habitat of the plant?(1mk)
- The number of stomata on the lower and upper surfaces of two leaves from plant species x and y were counted under the field of view of a light microscope. The results were as shown below.
Leaf Number of stomata Upper surface Lower surface x 4 12 y 20 23 - Which of the two leaves would be expected to have a lower rate of transpiration(1 mk)
- Give a reason for your answer in (a) above.Imk)
- Construct a dichotomous key for the animals listed below. Part of the key has already been constructed.Bird Snake, Lizard, Hyena.(4mks)
- Animal a mammal....... Hyena.
- Animal not a mammal... go to R.
- Other than transport of substances, state two other functions of mammalian blood.(2mks)
- Some students set-up the apparatus shown below to demonstrate the breeding mechanism in a mammal.
- What structure in a mammal is represented by each of the following?
- The glass tube.(Imk)
- The ballons.(Imk)
- The bell jar.(Imk)
- String
- What happens when you pull the string downwards?
- What structure in a mammal is represented by each of the following?
- The diagram shown below represents a part of the nephron. Use it to answer the questions that follow
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- Name the parts labeled A,B,C and D.(2mks)
- Name the fluids found in C and D.(2mks) C
- Name the process by which the fluid found in D is formed(Imk)
- Mention one difference in the composition of the fluids in C and D.(Imk)
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- Apart from having many features in common, state another characteristic of members of a Species (1mk)
MARKING SCHEME
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- Presence of ribosomes for protein synthesis;
- Presence of channels for transport of proteins and other substances; (1mk)
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- Number of wings
- number of legs and other appendages;
- number of body parts;
- type of eyes (simple or compound) max;1mk each
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- Diffusion is movement of particles(ions ,molecules) from where they are more to where they are few against a diffusion gradient ;(1mk)
- Active transport is the movement of ions/molecules from where they are few to where they are more using energy against a concentration gradient; (1mk)
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- Upper jaw = 8x2=16
- Lower jaw=7x2 =14/30;(1mk)
Or (2+5+ 8) x 2 = 30 teeth. - Herbivorous ;(1mk)
- it has the molar, premolars and incisors except canines ;(1mk)
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- To increase the surface area over which gases will diffuse;Acc.oxygen or carbon (vi) oxide for gases.(1mk
- Carbonic anhydrase;
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- Vitamin K;
- Thrombokinase /thromboplastin;
- Calcium /calcium ions; (½mk)
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- Heparin is a chemical substance that prevents blood form clotting within the blood vessels;(1mk
- Histamine is a chemical substance that is produced by tissue cells after an injury/sting/allergic reaction ;(1mk)
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- Modulla oblongata;(1mk)
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- the nostrils have a mucus lining that traps dust unlike the mouth
- Nostrils have cilia that facilitate the movement of dust particles outwards;
- Nostrils have chemoreceptorۥs for detecting smells/chemicals unlike the mouth ;(max 2=2mks)
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- Energy/ATP;(1mk)
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- A-Matrix;
- B- Cristae;
- C.Outer membrane
- D-Inner membrane; (½mk @ max 2mks)
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- Little or no insulin in the blood;(1mk)
- Boil a little urine sample with Benedictۥs solution; an orange precipitate confirm presence of sugar in the urine;(2mks)
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- Ecological niche-the position an organism occupies and the role itpalys in a habitat;(1mk)
- Habitat – a specific place where an organism lives/adapted to live ;(1mk)
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- Diaphragm – regulates the amount of light passing through the specimen;(1mk)
- Objective lenses-for magnification of the specimen;(1mk)
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- Respiratory quotient-the ratio of the volume of carbon (iv)oxide produced to that of oxygen used in a respiratory process;(1mk)
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- R.Q =70cm3= 0.7;(1mk)
- Lipid;(1mk)
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- An increase in amount of haemoglobin,an increase in the number of red blood cells;(2mks)
- To increase the surface area for transport of oxygen/to increase the volume of oxygen in the body/to trap more oxygen;(1mk)
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- A greater number of chloroplasts that trap light of low intensity;
- Their leaves are highly dissected /branched to increase the surface area for photosynthesis;
- Epidermis has chloroplasts; (max 2=2mks)
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- Bacillus anthracis;(1mk)
- Neisseria gonorrheae;(1mk)
- Bordetalla pertusis;(1mk)
- Due to anaerobic respiration; hence production of ethanol in the roots; which kills them and the whole plant;(3mks)
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- A and B ;(1mk each)
- They may be transfused with all other blood group’s they lack antibodies ‛aۥand‛ bۥ ;max (2mks)
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- thermoregulation/regulation of body temperature;
- Osmoregulation/regulation of water and salts.
- Blood sugar regulation ;(3mks)
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- are elongated to increase the surface area of absorption;
- their hypertonic sap enables osmosis to take place;
- Presence of a thin cell membrane to quicken diffusion ;(max 2=2mks)
- Translocation ;(1mk)
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- to reduce diffusion distance of carbon (iv) oxide /reduce the penetration distance of light;
- for gaseous exchange /store gases;
- allows gaseous exchange /allows transpiration to take place;
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- Secondary consumer;(1mk)
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- Grass antelopes lions vulture;
- Grass caterpillars Guinea fowl Vulture;(1mk)
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- Grass;(1mk)
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- Many organism’s depend on it for food/energy, being the primary producer;
- energy is lost during its transfer to higher levels through respiration, excretion and defecation ;(2mks)
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- Low temperatures inactivate enzymes;
- increase in temperature up to the optimum increase the reaction rate/turn over;
- higher temperatures above the optimum denatures enzymes;(3mks)
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- Desert/semi a desert; cc.arid/semi-arid areas;rej. Dry areas(1mk)
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- Presence of large and succulent leaves;
- pressure of thorns /prickles ;(2mks)
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- X; (1mk)
- Has fewer stomata on both sides of the leaf than Y;(1mk)
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- 1a)Animal a mammal …………………………………hyena;
- Animal not a mammal……………… go to 2;
- Animal with body covered with feathers………………. Bird;
- Animal with body not covered with feathers……………….. go to 3(1mk)
- Animal with legs………………..lizard;(1mk)
- Animal without legs……………………………………….snake ; (1mk)
Acc.any other correct
Key.
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- Defense against infections;
- Distribution of heat;
(1mk each)
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- Trachea; (1mk)
- Lungs (1mk)
- Rib cage;(1mk)
- Diaphragm;(1mk)
- Volume in the bell jar will increase ; and pressure will decrease in the bell jar;air will rush into the lungs filling them /inflating them;(3mks)
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- A- Afferent arteriole;
- B-Efferent arteriole;
- C-Glomerulus ;
- D-Bowman’s capsule;(½mk=2mks)
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- C- Blood;(1mk)
- D- Glomerulus filtrate ;(1mk)
- Ultrafiltration ;(1mk)
- The fluid in C contains blood cells and large protein molecules while the fluid in D does not;(1mk)
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- They interbreed to give rise to fertile offspring;(1mk)
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- The visking tubing is semi permeable; and allows the small glucose molecules into boiling tube by diffusion;(2mks)
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- the volume of the liquid in the boiling tube decreased .(1mk)
- The volume of the liquid in the visking tubing increased ;( 1mk)
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- are moist to dissolve gases;
- have a dense network of blood capillaries to transport gases;
- They have thin membranes/thin epithelium to reduce the diffusion distance;
- They have a large surface area for transport of more gases;
1mk each=3mks
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- Deamination;(1mk)
- Helps to regulate the amount of proteins /amino acids in the body;(1mk)
- Liver (1mk)
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