This biology question covers important biological concepts and processes. The step-by-step explanation below helps you understand the underlying mechanisms and reasoning.
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Here are the answers to questions 5 and 6: 5. (a) (i) Give three examples of endoparasites of cattle. Tapeworms* Flukes* (e.g., liver flukes) Roundworms* (e.g., stomach worms, lungworms) 5. (a) (ii) Enumerate two methods of controlling pests of cattle. Regular deworming* (administering anthelmintics) to control internal parasites. Dipping or spraying* with insecticides/acaricides to control external parasites like ticks and flies. Rotational grazing* to break the life cycle of parasites. 5. (b) (i) What is a formula mass of a compound? Formula mass is the sum of the atomic masses of all atoms in the empirical formula of an ionic compound or the molecular formula of a covalent compound. It is expressed in atomic mass units (amu). 5. (b) (ii) An atom Q has 12 neutrons and 11 protons: (α) calculate its mass number; Step 1: Identify the number of protons and neutrons. Protons = 11 Neutrons = 12 Step 2: Calculate the mass number. Mass number = Number of protons + Number of neutrons Mass number = 11 + 12 = 23 The mass number is 23. (β) write its electron configuration; Step 1: Determine the atomic number. Atomic number = Number of protons = 11 Step 2: Write the electron configuration for an atom with 11 electrons. The electron configuration is 1s^2 2s^2 2p^6 3s^1. (γ) what type of ion will Q form in a compound. Atom Q has 1 electron in its outermost shell (3s¹). It will tend to lose this electron to achieve a stable octet configuration. Therefore, Q will form a positive ion with a charge of +1 (a cation). 5. (c) (i) State two ways by which humans could be protected from harmful effects of radioactivity. Limiting exposure time* to radioactive sources. Increasing distance* from radioactive sources. Using shielding materials* (e.g., lead, concrete) between humans and radioactive sources. 5. (c) (ii) Give three uses of radioisotopes. Medical diagnosis and treatment* (e.g., Iodine-131 for thyroid disorders, Cobalt-60 for cancer therapy). Sterilization of medical equipment* and food products. Carbon dating* to determine the age of archaeological artifacts. Industrial gauging* (e.g., measuring thickness of materials). 5. (d) State five effects of climate change on humans. Increased frequency and intensity of extreme weather events* (e.g., heatwaves, floods, droughts), leading to loss of life and property. Food insecurity* due to disrupted agricultural patterns and reduced crop yields. Spread of vector-borne diseases* (e.g., malaria, dengue fever) as warmer temperatures expand vector habitats. Displacement and migration* of populations due to rising sea levels and uninhabitable regions. Impacts on mental health* due to stress, anxiety, and trauma from environmental disasters and uncertainty. 6. (a) (i) What are alkanoates? Alkanoates are a class of organic compounds also known as esters, formed from the reaction between an alkanoic acid (carboxylic acid) and an alcohol. They typically have the general formula RCOOR', where R and R' are alkyl groups. 6. (a) (ii) State three uses of alkanoates? Used as flavorings and fragrances* in food, perfumes, and cosmetics due to their pleasant fruity smells. Used as solvents* for paints, varnishes, and glues. Used in the production of polymers* (e.g., polyesters). 6. (b) (i) Explain the term weathering. Weathering is the process of breaking down rocks, soil, and minerals as well as wood and artificial materials through contact with the Earth's atmosphere, biota, and waters. It can be physical (mechanical), chemical, or biological. 6. (b) (ii) State three ways of maintaining soil fertility on a sloppy land. Terracing:* Creating level steps or platforms on slopes to reduce water runoff and soil erosion. Contour ploughing:* Ploughing parallel to the contours of the slope to create ridges that slow down water flow. Cover cropping:* Planting vegetation to cover the soil surface, protecting it from erosion and adding organic matter. Strip cropping:* Alternating strips of different crops (e.g., row crops with close-growing crops) along the contours. 6. (c) (i) Give two reasons why genetic variation is important in living organisms. Enhances adaptability:* Genetic variation allows populations to adapt to changing environmental conditions, increasing their chances of survival. Drives evolution:* It provides the raw material for natural selection, leading to the evolution of new species and traits. Increases disease resistance:* A diverse gene pool can make a population more resilient to diseases, as some individuals may possess resistance. 6. (c) (ii) Give three examples of genetic variations in humans. Eye color* (e.g., blue, brown, green). Blood type* (e.g., A, B, AB, O). Hair color and texture*. Height*. Susceptibility to certain diseases*. 6. (d) (i) State Archimedes principle. Archimedes' principle states that the buoyant force (upthrust) on an object submerged in a fluid is equal to the weight of the fluid displaced by the object. **6. (d) (ii) A boat of volume 200 \, m^3 floats on sea water of density $10