WAEC SSCE - Agricultural Science - 2004

Maelezo ya Majibu

Maelezo ya Majibu

The viral disease described is likely to be "rinderpest". Rinderpest is a highly contagious viral disease that affects ruminants such as cattle, buffalo, and sheep. It is characterized by symptoms such as high fever, nasal and ocular discharge, and bloody diarrhea. It can be fatal in up to 90% of infected animals, making it a significant threat to livestock populations.

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Of the four options listed, sprinkler irrigation is best for a farm with an undulating landscape. This is because sprinkler irrigation can apply water to crops in a uniform manner, regardless of the terrain, by spraying water over the crops. Sprinklers can be set up on risers or towers to accommodate changes in elevation, and can be adjusted to spray water at different angles and rates to match the slope of the land. Flooding, furrow, and basin irrigation all rely on gravity to distribute water, and are therefore less effective on sloping land. Flooding, for example, can result in erosion and runoff on steep slopes, while furrow and basin irrigation can lead to uneven distribution of water on undulating land.

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Pasture crops are best used in preparing hay just after seed maturation. At this stage, the plants have reached their peak nutritional content, and the stems have begun to dry up, which makes them easier to cure for hay. Curing involves removing moisture from the plants to prevent spoilage during storage. If the plants are harvested before seed maturation, they will have less nutritional value, while harvesting them after they have started to dry up excessively will lead to excessive leaf loss, making the hay less nutritious.

Maelezo ya Majibu

Maelezo ya Majibu

Maelezo ya Majibu

The most essential part of a tractor in operating a mower is the power-take-off (PTO) shaft. This is because the PTO shaft transfers the power from the tractor's engine to the mower's cutting blades, which enables the blades to rotate and cut the grass. Without the PTO shaft, the mower will not receive power and will not be able to function.

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Mulching is a process that involves covering the soil with organic matter, such as leaves or straw, to protect it from erosion, retain moisture, and regulate soil temperature. This process helps to build up soil organic matter and nutrients, rather than depleting them. Therefore, mulching will not lead to the loss of nutrients from the soil. On the other hand, erosion, harvesting, and leaching can lead to the loss of nutrients from the soil. Erosion can cause topsoil to wash away, taking with it valuable nutrients. Harvesting removes nutrients that have been stored in crops, while leaching occurs when water carries nutrients deep into the soil or beyond the root zone, making them unavailable to plants.

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Nitrite is oxidized to nitrate by Nitrobacter. Nitrobacter is a type of bacteria that is involved in the process of nitrification, which is a part of the nitrogen cycle. During nitrification, ammonia is first converted to nitrite by Nitrosomonas bacteria, and then nitrite is further oxidized to nitrate by Nitrobacter bacteria. Nitrate is an important form of nitrogen that plants can use for growth.

Maelezo ya Majibu

Maelezo ya Majibu

Maelezo ya Majibu

Plant breeders aim at obtaining all of the following traits mentioned in the options except "adaptation of pollination". They focus on developing crops that have tolerance to climatic extremes, resistance to pests, disease, and pathogens, and are uniform in their time of maturity. Adapting pollination is not a common objective of plant breeding as it is a natural process that occurs in the plant reproductive cycle. However, plant breeders may select for specific traits related to pollination, such as self-fertility or cross-compatibility, in order to improve the quality or yield of the crop.

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The land tenure system that results in fragmentation of land is inheritance. This is because when land is passed down from one generation to another through inheritance, it is often divided among the heirs of the deceased. Over time, this can result in the fragmentation of land into smaller and smaller parcels, which can be difficult to manage and cultivate efficiently. This is a common issue in many parts of the world, particularly in areas where land is a scarce resource and population growth is high.

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Newcastle disease is caused by a virus. The Newcastle virus is highly contagious and affects birds, particularly domestic poultry such as chickens and turkeys. The virus is spread through contact with infected birds or their secretions, or through contact with contaminated feed, water, equipment or clothing. The disease can cause respiratory, digestive and nervous system symptoms in birds, and can be fatal. Vaccination is an effective way to prevent Newcastle disease in poultry.

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Coconut is not a common staple food in West Africa. Maize, cassava, and cowpea are staple foods in West Africa, meaning they are regularly consumed in large amounts and form a significant part of the region's diet. On the other hand, coconut is not a common crop in West Africa, and it is not typically consumed in large amounts as a staple food. Therefore, the correct answer is "coconut."

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The pregnancy hormone in female animals is progesterone. Progesterone is a hormone produced by the ovaries of female animals during pregnancy. It plays a critical role in the maintenance of pregnancy by preventing the uterus from contracting and thus maintaining a suitable environment for the developing fetus.

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The correct answer is "oestrus cycle". The oestrus cycle refers to the reproductive cycle in female animals that have a periodic sexual receptivity and ability to conceive. The interval between the beginning of one heat period (when the female is in oestrus) to the beginning of another is called the oestrus cycle. The length of the oestrus cycle varies depending on the species of animal, but it typically lasts from a few days to several weeks.

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Organic manure has several benefits when applied to the soil. It helps to improve soil fertility, enhances soil structure, promotes soil aeration, and increases the availability of essential nutrients to plants. However, one of the disadvantages of using organic manure on the soil is that it may spread diseases fast. Organic manure, especially if it is not well-treated or sterilized, may contain pathogens, weed seeds, or other harmful microorganisms that can infect plants and cause diseases. Therefore, it is essential to properly compost, sterilize, or treat organic manure before applying it to the soil to reduce the risk of disease spread.

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A subsistence farmer is one who farms for the benefit of his family, while a commercial farmer farms for profit. Therefore, the factor that differentiates a subsistence from a commercial farmer is that the former produces for the benefit of his family. A subsistence farmer is not concerned with making a profit or producing for the market but rather focuses on producing enough food to sustain his family's needs. In contrast, a commercial farmer produces crops or livestock primarily for sale and profit.

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The act of parturition in ewe is known as lambing. This is the process of giving birth to lambs in sheep. It involves the expulsion of the fetus and the placenta from the uterus of the ewe. Lambing usually occurs between the months of December and May, and the gestation period of ewes is about 145 to 155 days. During lambing, the ewe requires special care and attention to ensure the safe delivery of the lamb and the health of both the ewe and the newborn lamb.

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The most unreliable source of farm power is wind. This is because wind power depends on the strength and consistency of the wind. If the wind is too weak or too strong, it can't generate enough power. Also, the availability of wind energy is not constant and it can vary from one season to another. In addition, wind turbines are prone to mechanical breakdowns, which can result in extended periods of downtime. As a result, wind power is not always a dependable source of energy for farmers, especially during critical times when power is urgently needed.

Maelezo ya Majibu

Maelezo ya Majibu

The question is asking which of the given options is NOT a function of a farm manager. The answer is "financing agricultural projects." A farm manager's primary functions are to make decisions, coordinate farm activities, and supervise farm laborers. While a farm manager may be involved in financial management, such as creating budgets or managing cash flow, their primary role is not to finance agricultural projects.

Maelezo ya Majibu

Maelezo ya Majibu

The soil water that is tightly held to the surface of soil particles is known as hygroscopic water. This type of water is not easily available to plants because it is held too tightly to soil particles. Hygroscopic water is attracted to the soil particles by weak electrostatic forces, and it cannot be easily removed from the soil unless it is heated. This type of water is important for soil structure because it helps to maintain the pore space in the soil.

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Maize is a very important crop because, apart from serving as a staple food for human consumption, it forms the base of most livestock feeds. This means that it is an essential component in the production of meat, dairy products, and eggs, which are important sources of protein for human consumption. Additionally, maize can be processed into various food products such as corn flakes, cornmeal, and grits. It can also be used for producing germ oil, which is used in the production of margarine, cooking oil, and salad dressings. Finally, maize residues such as stover and cobs can be used for animal bedding, fuel, and as a source of organic matter for soil improvement.

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When there is an increase in government subsidies, farmers can produce their goods at a lower cost because the government is providing financial assistance to help offset some of the expenses incurred in production. This reduction in production costs leads to an increase in the supply of goods produced by farmers, since they can now produce more for the same cost. Therefore, the correct answer is: "falls, hence supply increases".

Maelezo ya Majibu

Maelezo ya Majibu

The best way to preserve maize grains on a large scale is by storing them in airtight containers or silos. This prevents moisture and insects from getting into the grains, which can cause spoilage or infestation. Storing maize grains under the sun or in soils may expose them to moisture and pests, while hanging them over fire places may expose them to smoke, which can affect the quality and safety of the grains. Earthen pots may not be suitable for large scale storage as they have limited capacity and may not be airtight. Airtight containers or silos can help to keep maize grains fresh and safe for a longer period of time, ensuring their availability and quality for consumption or sale.

Maelezo ya Majibu

Maelezo ya Majibu

Ananas comosus is a fruit crop, commonly known as the pineapple. It is a tropical plant that produces the juicy and sweet edible fruit called a pineapple, which is enjoyed by many people around the world. The fruit is harvested when it ripens and is commonly eaten raw or used in various culinary dishes and beverages.

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Out of the options provided, Tenera is a variety of oil palm. Tenera is a hybrid variety obtained by crossing Dura and Pisifera oil palm varieties. It is widely cultivated in Southeast Asia and is known for its high yield and resistance to diseases. Its fruit has a higher oil content compared to Dura and Pisifera varieties, making it suitable for commercial oil production.

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Maelezo ya Majibu

The activity that is not correct about extension agents is option C, which is training school leavers to become professional farmers. Extension agents are mainly responsible for educating farmers on modern and improved techniques in agriculture, providing them with the necessary information, and teaching them how to use new technologies, equipment, and practices to increase productivity and reduce wastage. They also teach farmers how to prepare and apply compost manure, among other things. However, it is not within their scope of duty to train school leavers to become professional farmers. This role is mainly carried out by agricultural training institutions such as colleges of agriculture and universities offering agricultural programs.

Maelezo ya Majibu

Maelezo ya Majibu

Black pod disease of cocoa is controlled by the application of fungicide. This is because black pod disease is caused by a fungus that attacks the pods of cocoa trees, resulting in loss of yield and quality of the crop. The application of fungicide helps to prevent or reduce the spread of the disease by killing or inhibiting the growth of the fungus. Other methods like farm sanitation and fumigation of soil may also help to control the disease indirectly by reducing the spread of spores and creating a healthier growing environment, but they are not direct methods of controlling the disease like the application of fungicide.

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Parboiling is a term associated with the processing of rice. Parboiling involves partially boiling the rice grains in their husks, then removing the husks and allowing the grains to dry before being milled. The process helps to improve the nutritional value and shelf life of the rice, as well as making it easier to mill.

Maelezo ya Majibu

Maelezo ya Majibu

An adult female goat is called a "doe".

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Maelezo ya Majibu

Maelezo ya Majibu

The method of fish preservation in which most of the moisture is lost is drying. Drying fish involves removing most of the moisture from the fish through exposure to the sun, smoke, or air. The reduction of moisture content in the fish prevents the growth of microorganisms that cause spoilage. The dried fish can be stored for long periods without refrigeration and can be rehydrated by soaking in water before cooking. This method of preservation is commonly used in areas where refrigeration is not readily available.

Maelezo ya Majibu

Maelezo ya Majibu

The land tenure system that encourages the establishment of permanent crops is the "freehold system." In this system, the individual or entity has the absolute ownership of the land and can use it as they wish, including planting permanent crops. They can also transfer the ownership of the land to another party, who will continue to have the same rights. Therefore, under the freehold system, farmers are more likely to invest in long-term crops such as fruit trees, which require a longer time to yield returns.

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Milking is the management practice that is specific to dairy farming. Milking is the process of extracting milk from the udder of a lactating dairy cow, which is the primary product of dairy farming. The milk is either sold for human consumption or processed into various dairy products such as cheese, butter, yogurt, and ice cream. Deticking is the process of removing ticks from the skin of the animal. Castration is the removal of the testicles of a male animal to prevent breeding and enhance meat quality. Deworming is the administration of drugs to eliminate internal parasites in livestock.

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The equilibrium price of rice is the price at which its supply equals its demand. In other words, it is the price where buyers are willing to buy the same quantity of rice that sellers are willing to sell. At this price, there is no excess supply or excess demand, and the market is said to be in a state of balance. If the price is set above the equilibrium price, there will be excess supply, and if it is set below the equilibrium price, there will be excess demand. Therefore, the equilibrium price is a key determinant of the price at which rice is sold in the market.

Maelezo ya Majibu

Clay particles have excess negative charges, which makes them able to attract cations in the soil. The negative charges on the clay particles attract positively charged cations, such as calcium, magnesium, and potassium, which are important nutrients for plant growth. The attraction between the clay particles and the cations is known as cation exchange, and it helps to hold these nutrients in the soil where they can be accessed by plant roots. This is why clay soils are often very fertile, and why adding clay to sandy soils can help to improve their fertility.

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In cassava farming, the application of nitrogen fertilizer promotes rapid growth at the expense of tuber formation. Nitrogen is a macronutrient that promotes the growth of leaves and stems in plants, but when present in excess, it suppresses the development of the root system and reduces the yield of tubers in cassava. Therefore, cassava farmers need to carefully manage the use of nitrogen fertilizer to avoid promoting excessive vegetative growth at the expense of tuber formation.

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The farm implement used for planting grains is the drill. The drill is a machine used for planting crops in rows. It is designed to make evenly spaced holes in the soil, drop in a seed, and cover it up. The drill is commonly used for planting grains such as wheat, corn, and soybeans. It is an important tool for modern agriculture because it allows farmers to plant large areas quickly and efficiently.

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The main reason for not keeping birds meant for commercial egg production under the extensive system of management is that birds waste a lot of productive energy roaming about. When birds are kept under the extensive system of management, they are allowed to roam around freely in search of food and water. This requires a lot of energy and time, which could have been used for egg production. As a result, birds under this system tend to lay fewer eggs than birds kept under the intensive system of management, where food and water are provided in a concentrated area. Therefore, the extensive system is not suitable for commercial egg production as it is not efficient in terms of egg production.

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Water power can be harnessed by using turbines which convert the energy from the moving water into mechanical energy. This mechanical energy is then used to drive an electrical generator that converts the mechanical energy into electrical energy that can be used to power homes, buildings, and other electrical appliances. Therefore, the correct option is turbines.

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Leguminous cover crops do not reduce the soil microbial population. Leguminous cover crops such as clover, beans, and peas have root nodules that contain nitrogen-fixing bacteria. These bacteria are capable of taking nitrogen from the air and converting it into a form that can be used by plants. This process leads to an increase in soil nitrogen content, which can enhance plant growth and soil fertility. Leguminous cover crops also help to bind soil particles together through their roots, which can reduce soil erosion. Additionally, they can aid in improving the soil organic matter content, which can improve soil structure and water holding capacity. However, leguminous cover crops do not reduce the soil microbial population. In fact, they can provide a habitat for beneficial soil microorganisms, which can enhance soil health and productivity.

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The answer is "climatic conditions". The factors necessary for siting fish pond are the availability of a reliable source of water supply, type of soil that is suitable for pond construction, and topography which should be flat or gently sloping. Climatic conditions, although important, are not necessary for siting a fish pond because the pond can be constructed in different climates provided that the temperature and humidity levels are within the acceptable range for the species of fish being reared.

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Bacteria and fungi are the most important soil micro-organisms that cause decay and nutrient recycling. Bacteria are the most numerous micro-organisms in the soil and are responsible for the decomposition of organic matter into simple compounds. Fungi, on the other hand, are important in the breakdown of complex organic matter such as lignin and cellulose. Together, these micro-organisms are responsible for breaking down dead plant and animal matter, releasing nutrients back into the soil that can be used by other plants. This process is essential for maintaining healthy soil and sustaining plant growth.

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Igneous rocks are rocks that solidify from molten or partially molten material. Igneous rocks formed within the crust are called plutonic rocks or intrusive rocks. Plutonic rocks form when magma solidifies slowly below the Earth's surface, resulting in a coarse-grained texture. In contrast, volcanic rocks or extrusive rocks form when magma or lava solidifies quickly on the Earth's surface, resulting in a fine-grained texture. Therefore, the correct answer to the question is plutonic.

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