Explain the roles and importance of soil organisms, and list human activities that affect them.

Here are the answers to your questions: Question One a) Two examples of soil organisms classified as: (i) Micro-organisms: Bacteria Fungi (ii) Macro-organisms: Earthworms Ants b) One importance of each of the four organisms: Bacteria: Decompose organic matter, releasing nutrients for plants. Fungi: Form symbiotic relationships with plant roots (mycorrhizae) to enhance nutrient uptake. Earthworms: Improve soil aeration and drainage by creating burrows. Ants: Mix and aerate soil, and can help in seed dispersal. c) Six human activities that affect the diversity and population of soil organisms: 1. Use of pesticides and herbicides: These chemicals can directly kill beneficial soil organisms, reducing their populations and diversity. 2. Intensive tillage: Frequent and deep plowing disrupts soil structure, destroys habitats, and exposes organisms to predators and harsh environmental conditions. 3. Deforestation and land clearing: Removal of vegetation exposes soil to erosion and alters the microclimate, negatively impacting soil organisms. 4. Application of synthetic fertilizers: Excessive use can alter soil pH and nutrient balance, favoring certain species while harming others, thus reducing diversity. 5. Pollution from industrial and domestic waste: Introduction of heavy metals, plastics, and other toxins into the soil can be lethal to many soil organisms. 6. Monoculture farming: Growing a single crop repeatedly reduces the diversity of plant residues, which in turn limits the food sources and habitats for a wide range of soil organisms. Question Two a) Two elements required by plants in: (i) Large quantities (Macronutrients): Nitrogen (N) Phosphorus (P) (ii) Small quantities (Micronutrients): Iron (Fe) Boron (B) b) Two fertilizers which can supply each of the following elements in soil: (i) Nitrogen: Urea Ammonium Sulfate (ii) Phosphorus: Triple Superphosphate (TSP) Diammonium Phosphate (DAP) c) Given that Urea ((NH_2)_2CO) contains 47.7% Nitrogen and is applied at a rate of 0.05kg/m^2, calculate: (i) The amount of nitrogen in 20kgs of Urea fertilizer. Step 1: Calculate the percentage of nitrogen in the urea. Nitrogen amount = 47.7\% × 20\, kg Step 2: Convert the percentage to a decimal and multiply. Nitrogen amount = (47.7)/(100) × 20\, kg = 0.477 × 20\, kg = 9.54 kg (ii) Amount of urea to be applied in a crop field measuring 5m by 10m. Step 1: Calculate the area of the crop field. Area = length × width = 10\, m × 5\, m = 50\, m^2 Step 2: Calculate the total amount of urea needed based on the application rate. Amount of urea = Area × Application rate = 50\, m^2 × 0.05\, kg/m^2 = 2.5 kg (iii) Other than nitrogen, list three elements supplied by urea. Carbon (C) Oxygen (O) Hydrogen (H) Question Three a) One cause of anaemia in pregnant women: Iron deficiency (due to increased demand for iron during pregnancy). b) Explain three effects of anaemia: 1. Fatigue and weakness: Reduced oxygen-carrying capacity of blood leads to less energy for body functions, causing persistent tiredness. 2. Pale skin and mucous membranes: Lower levels of hemoglobin, which gives blood its red color, result in a noticeable paleness of the skin, gums, and inner eyelids. 3. Shortness of breath and dizziness: The body tries to compensate for reduced oxygen by increasing breathing and heart rate, leading to breathlessness, especially during exertion, and lightheadedness. c) Recommend four foodstuffs for prevention of anaemia: 1. Red meat (e.g., beef, lamb) 2. Leafy green vegetables (e.g., spinach, kale) 3. Legumes (e.g., lentils, beans) 4. Citrus fruits (e.g., oranges, lemons) – rich in Vitamin C, which aids iron absorption. d) Besides anaemia, explain four health challenges faced in your community: 1. Malaria: A parasitic disease transmitted by mosquitoes, causing fever, chills, and flu-like illness, leading to significant morbidity and mortality, especially among children and pregnant women. 2. HIV/AIDS: A chronic, life-threatening condition caused by the Human Immunodeficiency Virus, which weakens the immune system, making individuals susceptible to opportunistic infections and cancers. 3. Diarrheal diseases: Often caused by contaminated food and water, these diseases lead to severe dehydration and are a major cause of death, particularly in young children, due to poor sanitation and hygiene. 4. Tuberculosis (TB): A bacterial infection primarily affecting the lungs, spread through the air, causing chronic cough, fever, and weight loss, and remains a significant public health concern due to its infectious nature. That's 2 down. 3 left today — send the next one.