BIOLOGY
PAPER 1
INSTRUCTIONS
- Answer all the questions in the spaces provided
- State the advantages of internal fertilization in mammals (2mks)
-
- State the ideas proposed by Lamarck in his theory of evolution (2mks)
- Why is Lamarck’s theory not acceptable? (1mks)
- What is meant by the term irritability? (1mk)
- State three aspects that can be used to estimate growth in seedlings (3mks)
- Name the organelle that is involved in each of the following
- Manufacture of lipid (1mk)
- Formation of lysosomes (1mk)
- State the importance in living organisms
- Nutrition (1mk)
- Excretion (1 mk)
- Explain the meaning of the following
- Flaccid cell (1mk)
- Crenated cell (1mk)
- Explain the following
- Ovaries can be removed from a human female after the fourth month of pregnancy without terminating the pregnancy (2mks)
- Human testes are located to hang outside (2mks)
-
- Explain how a human stomach is adapted to;
- Protein digestion (2mks)
- Churning (2mks)
- Explain how a human stomach is adapted to;
- State three characteristics of class crustacea (3mks)
-
- Describe the condition known as varicose veins (2mks)
- What is the role of blood platelets in the blood clotting process (2mks)
- What would be the expected results of a test cross? (2mks)
-
- Name the products of anaerobic respiration in;
- Plants (1mk)
- Animals (1mk)
- What is oxygen debt? (1mk)
- Name the products of anaerobic respiration in;
-
- Explain how the following occur during gene mutation
- Deletion (1mk)
- Inversion (1mk)
- What is mean by the term allele? (1mk)
- Explain how the following occur during gene mutation
-
- Name the compound that stores energy released during oxidation of glucose (1mk)
- Explain what happens to excess amino acids in the body (3mks)
- Explain the role of the following hormones in plants
- Florigen (1mk)
- Ethene (1mk)
- An individual is blood group B positive
- Name the antigens in the individuals blood (2mks)
- Give the reason why the individual cannot receive blood from a blood group A donor (2mks)
-
- What is meant by each of the following
- Pyramid of numbers (1mk)
- Pyramid of numbers (1mk)
- During an ecological visit to Savannah grassland, students were able to see lions, antelopes, vultures and pastoralists grazing their cattle. Construct a food chain with four consumer levels to illustrate the energy flow in the ecosystem. (2mks)
- What is meant by each of the following
- A group of students placed some bean seeds on moist cotton wool in a retort flask as shown below
- Explain the expected observation after three days (3mks)
- State the control experiment for the observation above (1mk)
-
- Name the surface involved in gaseous exchange in a locust (1mk)
- How is the surface named above adapted for gaseous exchange (4mks)
- What would happen to a cell if its nucleus was removed? Explain. (2mks)
- A student set up an experiment to investigate a certain process
- Identify the physiological process being instigated (1mk)
- What observation would the student make on the visking tubing after 30 minutes (1mk)
- Explain your observation in (b) above (2mks)
- When testing for starch a leaf from a plant that had been kept in the sun for six hours was put in boiling water for 10 minutes. It was then put in a test tube full of ethanol. The test tube containing ethanol was put in a hot water bath. The leaf was then removed and dipped in a beaker of cold water. The leaf was then tested for starch.
- Why was the plant kept in the sun for six hours (1mk)
- Why was the test tube containing ethanol not heated directly (1mk)
- Why was the leaf boiled in ethanol (2mks)
- A certain plant was found to have the following features
- Parallel venation in leaves
- Sheath like petiole
- Flower parts in multiples of three- Name the class to which the plants belongs (1mk)
- Describe how the following characteristics would appear in the plant
- Vascular bundles in the stem (1mk)
- Root system (1mk)
- The heart of a chicken continued beating minutes after the lead was cut off. Explain (2mks)
-
- Distinguish between homologous and analogous structure (2mks)
- Explain the term continental drift as used in evolution (2mks)
MARKING SCHEME
- Higher chances of fertilization
Embryo / gamete / foetus is protected from external environment conditions -
- Use and dis use
Acquired traits can be passed on to offspring - Acquired traits cannot be inherited
No evidence to support the theory
- Use and dis use
- Irritability is the ability of an organism to detect (interdict) and respond to changes in the environment / stimulus.
- Height / length
Weight / mass
Surface area -
- Smooth endoplasmic reticulum
- Golgi bodies / golgi apparatus / accept golgi bodies
-
- Nutrition – acquisition and utilisation of nutrients / accept assimulations
- Excretion – Elimination of metabolic wastes to prevent accumulation to toxic level
-
- Flaccid cell – a flubby / shrunk plant cell that has lost water by osmosis
- Crenated cell – A shrunk animal cell / Red blood cell that has lost water by Osmosis
-
- A progesterone hormone is secreted by the placenta to maintain the pregnancy
- Testes located outside the body to provide a cool environment that is conducive for good quality sperm formation.
-
- Has gastric glands; that secret gastric juice; accept a component of gastric juice . Hel / pepsin / Rennin / Rj renin
- Thick muscular wall that contract and relax
- Fused head and thorax / cephalothorax (often) projected by a carapace
Gaseous exchange through gills
Two pairs of antennae
Five or more pairs of limbs / 5 -20 pairs of limbs
A pair of compound eyes
Three pairs of mouth parts -
- Weakened / defective valves in veins causing blood / tissue fluid to accumulate; leading to swelling
- When exposed to air they disintergrate / rapture/ burst; releasing thromboplastic/ thrombokanase
- All the offsprings shows the dorminant characteristics ; of half the offspring show the recessive while the other half show dominant characteristics
-
-
- Ethanol, carbon(iv)oxide, energy / 2ATP/ 210Kjo,
- Lactic acid, energy / 2ATP/ 150Kj;
- Oxygen required to get rid of lactic acid during anaerobic respiration / oxygen required to convert accumulated lactic acid to water, carbon (iv) oxide and energy
-
-
-
- Deletion – soma bases / nucleotides of a gene are removed
- Order of some bases / nucleotides of a gene is reversed
- Alternate form of a gene
-
-
- Adenosine triphosphate /ATP
- Deaminated
Resulting information of ammonia
Ammonia combines with carbon(iv) oxide to form urea and water
Urea is passed out through urine;
Carbohydrate group is oxidised STORED AS GLYCOGEN
-
- Promotes flowering
- ethene
-
- Causes uniform ripening of fruits
- Induces thickening of stems / inhibits stem elongation
- Promotes flower morphogenesis
- Causes abscission of leaves / leaf fall fruits
-
- Antigen B
Rhesus factor / antigen - Has antibody a in the blood plasma of the recipient and will correspond with antigen A in the donors blood hence there will be antigen antibody reaction / agglutination.
- Antigen B
-
-
- Pyramid of numbers – Represents the (total) number of organisms at each trophic level
- Grass – cattle / antelope – man / pastoralists – Lion – Vulture
-
-
- Level of potassium hydroxide vides in the flask; oxygen is yused in respiration during germination while carbon(iv) oxide is absorbed by potassium hydroxide; the rise is due to reduction in pressure in the flask;
- Use dry cotton wool instead of moist cotton wool / use water instead of potassium hydroxide
-
- Tracheoles
- Adaptations of tracheoles to their functions
- Always moist for gases to dissolve and diffuse in solution form
- Highly branched to serve every cell
- Consist of numerous tubules to increase surface area for gaseous exchange
- Has thin epithelium to reduce distance for diffusing molecules for easier gaseous exchange
- The cell would die; because all cell activities would cease due to removal of nucleus which controls all cell activities
-
- Osmosis
- Visking tubing would swell
- 0.8m sodium chloride solution in the visking tubing is hypertonic to 0.5m sodium chloride solution in the beaker; water moves from the beaker to the visking tubing by osmosis
-
- for starch to be formed in the leaves
- Ethanol is highly inflammable
- To kill living tissues in the leaf thus stopping further chemical reaction
To rupture and open the starch grain
-
- Monocotyledonae
-
- Scattered vascular bundles
- Fibrous root system
- Heart muscles are myogenic hence able to initiate their contraction without nervous stimulation.
-
- Homologous structures are structures that have a common embryonic origin but have been modified to perform different functions ;while analogous structures have different embryonic origin but have evolved to perform different functions.
- the breaking up ,drifting and separation; of the big land mass to form the present day different continents;
Download Biology Paper 1 Questions and Answers - MECS Cluster Joint Pre Mock Exams 2021/2022.
Tap Here to Download for 50/-
Get on WhatsApp for 50/-
Why download?
- ✔ To read offline at any time.
- ✔ To Print at your convenience
- ✔ Share Easily with Friends / Students