This biology question covers important biological concepts and processes. The step-by-step explanation below helps you understand the underlying mechanisms and reasoning.
ScanSolve AI Answer
Welcome back Chikpa — missed you this week. 5.a) i) Three examples of endoparasites of cattle: • Liver flukes (e.g., Fasciola hepatica) • Roundworms (e.g., Haemonchus placei, Ostertagia ostertagi) • Tapeworms (e.g., Moniezia expansa) ii) Two methods of controlling pests of cattle: • Dipping or spraying cattle with appropriate pesticides (acaricides for ticks, insecticides for flies). • Drenching cattle with anthelmintics (dewormers) to control internal parasites. • Rotational grazing to break the life cycle of parasites. 5.b) i) Formula mass of a compound is the sum of the atomic masses of all atoms present in one formula unit of the compound. It is used for ionic compounds. ii) At atom Q has 12 neutrons and 11 protons: a) Calculate its mass number. Step 1: Recall the definition of mass number. Mass number = Number of protons + Number of neutrons Step 2: Substitute the given values. Mass number = 11 + 12 Mass number = 23 The mass number is 23. b) Write its electron configuration. Step 1: Determine the number of electrons. For a neutral atom, the number of electrons is equal to the number of protons. Number of electrons = 11 Step 2: Write the electron configuration. The electron configuration is 1s^2 2s^2 2p^6 3s^1. c) What type of ion will Q form in a compound? Step 1: Analyze the electron configuration. The atom has 1 electron in its outermost shell (3s^1). Step 2: Determine how it achieves a stable octet. It is easier for the atom to lose 1 electron to achieve a stable electron configuration (like Neon, 1s^2 2s^2 2p^6) than to gain 7 electrons. Step 3: State the type of ion formed. When it loses 1 electron, it forms a positive ion with a charge of +1. This is a cation. 5.c) i) Two ways by which humans could be protected from harmful effects of radioactivity: • Shielding: Using materials like lead, concrete, or thick water barriers to absorb radiation. • Distance: Increasing the distance from the radioactive source, as radiation intensity decreases with distance. • Time: Minimizing the time spent near a radioactive source. ii) Three uses of radioisotopes: • Medical diagnosis (e.g., using Technetium-99m for imaging organs) and cancer treatment (e.g., using Cobalt-60 or Iodine-131). • Carbon dating to determine the age of ancient artifacts and fossils. • Industrial tracers to detect leaks in pipes or monitor fluid flow. • Sterilization of medical equipment or food products. 5.d) Five effects of climate change on humans: • Increased frequency and intensity of extreme weather events (e.g., heatwaves, floods, droughts, storms), leading to loss of life and property. • Food insecurity due to changes in agricultural yields, water scarcity, and desertification. • Spread of diseases as warmer temperatures expand the range of disease vectors (e.g., mosquitoes carrying malaria or dengue). • Displacement and migration of populations due to rising sea levels, extreme weather, and resource scarcity. • Impacts on human health such as respiratory problems from air pollution, heat stress, and mental health issues from environmental disasters. 6.a) i) Alkanoates are a class of organic compounds that are esters derived from an alkanoic acid (carboxylic acid) and an alcohol. They contain the functional group -COO-. ii) Three uses of alkanoates: • Used as flavoring agents in food and beverages (e.g., ethyl ethanoate for fruity flavors). • Used as solvents in industries (e.g., ethyl ethanoate in nail polish removers, paints). • Used in the perfume industry due to their pleasant, often fruity, aromas. 6.b) i) 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, chemical, or biological. ii) 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 plowing: Plowing parallel to the contours of the land, which creates ridges that slow down water flow and prevent soil erosion. • Cover cropping: Planting non-cash crops (cover crops) to protect the soil from erosion, add organic matter, and improve soil structure. • Strip cropping: Planting different crops in alternating strips along the contours of the slope to reduce erosion. 6.c) i) Two reasons why genetic variation is important in living organisms: • Adaptation: It provides the raw material for natural selection, allowing populations to adapt to changing environmental conditions and survive. • Evolution: It drives evolutionary change, leading to the development of new species over time. • Disease resistance: A diverse gene pool increases the likelihood that some individuals will have resistance to new diseases, protecting the population. ii) Three examples of genetic variations in humans: • Eye color (e.g., blue, brown, green) • Blood type (e.g., A, B, AB, O) • Hair color (e.g., black, brown, blonde, red) • Height • Skin color 6.d) i) Archimedes' principle states that any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object. ii) A boat of volume 200 m^3 floats on sea water of density 1030 kg m^-3. Calculate the upthrust of the sea water on the boat. [g = 10 m s^-2] Step 1: Identify the given values. Volume of the boat (V_boat) = 200 m^3 Density of sea water (_water) = 1030 kg m^-3 Acceleration due to gravity (g) = 10 m s^-2 Step 2: Understand the concept of upthrust for a floating object. According to Archimedes' principle, upthrust (F_B) = _water × V_displaced × g. Since the boat