WAEC SSCE - Agricultural Science - 1999

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The characteristic symptoms of mosaic disease of crops are usually observed on the leaves. Mosaic disease is a viral disease that affects various crops, such as tobacco, tomato, cassava, and beans. It is called "mosaic" because it causes a mottled or mosaic-like pattern of discoloration on the leaves, which can range from light green to yellow, and to dark green to brown. The mosaic pattern is caused by the virus interfering with the chloroplasts, which affects the plant's ability to photosynthesize, leading to stunted growth, reduced yields, and in severe cases, death.

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Callosobruchus maculatus is a common pest of cowpea. This insect is known as the cowpea weevil and it is a major pest of stored cowpea grains. The adult weevils lay their eggs on the cowpea grains and the hatched larvae bore into the grains, feed on them and cause damage, making the grains unfit for consumption or seed purposes. Therefore, proper storage practices and control measures are necessary to prevent or minimize losses due to this pest.

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Miracidium is a stage in the life cycle of a liver fluke. Liver flukes are parasitic flatworms that typically live in the liver and bile ducts of various mammals, including humans. The life cycle of a liver fluke involves multiple stages, and the miracidium is the first larval stage that hatches from an egg laid by an adult fluke in the liver or bile ducts of an infected host. Once the miracidium hatches, it swims out of the egg and seeks out a specific type of snail, which serves as an intermediate host for the liver fluke. The miracidium then penetrates the snail's tissues and develops into a sporocyst, which produces many more larvae called cercariae. The cercariae are then released from the snail into the water, where they can infect a suitable mammalian host by burrowing through the skin. Overall, the miracidium stage is crucial in the life cycle of a liver fluke because it is the starting point for the complex series of developmental stages that ultimately enable the parasite to infect and reproduce within a mammalian host.

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The hormone responsible for milk let down in female farm animals is oxytocin. Oxytocin is a hormone that is produced in the hypothalamus and released by the posterior pituitary gland in response to certain stimuli such as suckling or milking. Oxytocin causes the milk ducts in the udder to contract and push milk into the teats, making it available for the young to suckle. This process is known as milk let down or milk ejection. Oxytocin also has other roles in reproduction, including stimulating contractions during labor and promoting bonding between mothers and their offspring. In farm animals, oxytocin is often administered as a drug to stimulate milk let down during milking and improve milk production. Therefore, oxytocin is the hormone responsible for milk let down in female farm animals.

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The A-horizon of the soil profile encourages the greatest level of microbial activity. The A-horizon is the top layer of the soil, where organic matter accumulates and mixes with minerals. This layer contains a lot of nutrients, water, and air, which are essential for the growth and activity of microorganisms like bacteria and fungi. These microorganisms play a vital role in breaking down organic matter into simpler compounds, which can be used by plants as nutrients. They also help in improving soil structure, water-holding capacity, and overall soil health. Therefore, the A-horizon is considered the most important layer of the soil for plant growth and soil fertility.

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The type of soil with a particle size of 0.02 to 0.002 mm is called "silt". Silt is a fine-grained soil that is composed of rock, mineral, and organic particles that are smaller than sand but larger than clay. It has a smooth, silky texture and can retain moisture better than sand due to its smaller particle size. Silt is often found in river beds, floodplains, and areas where there has been erosion and deposition of sediment. Its ability to retain moisture and nutrients makes it suitable for agriculture, as it provides a good growing medium for crops.

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Fertile soil is soil that contains all the essential plant nutrients in suitable proportions to support good plant growth. These essential plant nutrients include nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur, among others. When these nutrients are present in the soil in the right amounts, they help plants grow healthy and strong, producing high yields of crops. Therefore, fertile soil is necessary for successful agriculture and plant growth. The other options - well-aerated, easily drained, and capable of producing good cowpea harvests - are also important characteristics of fertile soil but do not fully capture the complete definition of fertile soil.

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The farm machine used for coupling many implements is a tractor. A tractor is a powerful vehicle with large rear wheels used mainly on farms for pulling machinery. It is used for many purposes, including tilling, plowing, harrowing, planting, and cultivating crops. The tractor is designed to be powerful enough to provide the necessary power to operate various farm implements, such as plows, cultivators, and harrows, making it an essential machine in modern agriculture.

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The natural resource utilized for production is land. Land provides the physical space for agricultural production and includes the soil, water, and climate necessary for growing crops or raising livestock. It is a crucial factor of production and without it, agricultural production would not be possible. Therefore, land is considered a natural resource that is essential for agricultural production.

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Gummosis disease of citrus is caused by a fungal infection. Gummosis is a plant disease that affects citrus trees, among others. The disease causes a variety of symptoms, including oozing or bleeding of sap from the trunk or branches, as well as the formation of gum-like lesions on the bark. In severe cases, gummosis can weaken the tree and make it more susceptible to other infections or stressors. The disease is caused by several species of fungi, which infect the bark and wood of the tree. The fungi are often introduced into the tree through wounds or other damage to the bark, and they can then spread through the tree's vascular system. As the fungi grow and reproduce, they cause the tree to produce excessive amounts of sap or gum in an attempt to defend itself. Overall, gummosis disease of citrus is caused by a fungal infection that can damage and weaken citrus trees if left untreated.

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The correct answer is lions, elephants, and leopards. Game reserves are areas of land where wildlife is protected and managed, and visitors can go to see and sometimes hunt animals. Lions, elephants, and leopards are examples of large wild animals that are typically found in game reserves. Cattle, sheep, goats, camels, donkeys, horses, chickens, ducks, and turkeys are not usually kept in game reserves because they are domesticated animals and are not typically found in the wild.

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The rock that is formed from shale is slate. Shale is a sedimentary rock composed of compressed clay, silt, and organic matter. When shale undergoes metamorphism due to heat and pressure, it transforms into slate. Slate is a fine-grained metamorphic rock that splits easily into thin, smooth layers, making it useful for roofing tiles, flooring, and other construction materials. Marble, quartzite, and limestone, on the other hand, are all different types of rocks that form from different processes. Marble is a metamorphic rock formed from limestone that has been exposed to high heat and pressure, while quartzite is a metamorphic rock formed from sandstone. Limestone is a sedimentary rock that forms from the accumulation of calcium carbonate deposits, such as shells and coral. In summary, slate is the rock that is formed from shale, while marble, quartzite, and limestone form through different processes.

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The tree species commonly planted for pulpwood is Gmelina. Gmelina is a fast-growing tree species that is popularly grown for pulpwood production. It is known for its excellent pulpwood qualities such as high pulp yield, low lignin content, and good fiber length. It is also resistant to pests and diseases, making it a low-maintenance tree species for pulpwood plantations.

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Ginger is propagated by using its rhizomes. The rhizome is an underground stem of the ginger plant that has nodes and buds, which can sprout new shoots and roots. To propagate ginger, a fresh and healthy rhizome is selected, and it is cut into smaller pieces with at least one bud or "eye" each. These pieces are then planted horizontally in well-drained soil, with the buds facing upward and the cut surface of the rhizome facing downward. The soil is kept moist, and new shoots emerge from the buds and develop into a new ginger plant. Ginger can also be propagated by using whole rhizomes or by dividing large rhizomes into smaller pieces. Propagation by using suckers, seeds, or tubers is not a common practice for ginger.

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None of the listed fishing gears can be used for total harvesting of ponds. - Hook and line: It involves catching fish one by one, and it's not a practical method for total harvesting of ponds, which could contain a large number of fish. - Harpoon: It's a tool used for catching large fish in open waters, and it's not suitable for use in ponds. - Basket trap: It's a passive fishing gear that captures fish as they swim into the trap. While it can be used in ponds, it is not a practical method for total harvesting of ponds since it only captures a small portion of the fish population at any given time. - Dragnet: It is a fishing gear used for capturing fish in large quantities. It can be used for total harvesting of ponds by enclosing the pond with a net and then pulling the net to capture all the fish.

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The records of money transactions in a farming business are termed farm accounts. These are financial records that document the inflow and outflow of money in the farm business. Farm accounts are essential for managing the finances of the farm business and making informed decisions about investments, expenses, and profits. They include information on income from crop and livestock sales, expenses for farm inputs such as seeds, fertilizers, and animal feed, and other costs such as labor, machinery, and repairs. Keeping accurate and up-to-date farm accounts helps farmers track their income and expenses, analyze their financial performance, and plan for the future. It also enables them to comply with tax and other regulatory requirements and obtain financing for the farm business. Overall, farm accounts are a crucial tool for managing the financial aspects of a farming business, helping farmers make informed decisions that support their long-term success.

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The easiest method of determining soil texture in the field is by feeling the soil. Soil texture refers to the relative proportion of sand, silt, and clay particles in a soil sample. The texture of soil has a significant impact on crop growth, nutrient availability, and water holding capacity. The feeling method involves taking a small amount of soil and rubbing it between your fingers to determine the proportion of sand, silt, and clay particles in the soil. Sand particles feel gritty, silt particles feel smooth, and clay particles feel sticky. By feeling the soil, you can estimate the texture of the soil sample and use this information to inform management practices.

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The answer to this question is "weeding". The question is asking about the processes involved in the marketing of cotton, which is a specific aspect of the cotton production process. Weeding is not part of the marketing process, as it is a farming activity that occurs during the growing season to remove unwanted plants that may compete with the cotton plants for resources. Processing, grading, and packaging are all important steps in preparing cotton for sale, while weeding is not directly related to the marketing of the product.

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The most suitable source of power for stationary equipment on a farm is electricity. This is because electricity is a reliable and consistent source of power that can be used to run a wide range of equipment, such as water pumps, milking machines, and grain mills. It is also relatively clean and easy to use compared to other sources of power, such as animal or manual labor. While machines may be used for specific tasks on a farm, they are not a source of power in themselves and require some form of power input, such as electricity or gasoline. Animals and human labor can also be used to power equipment, but they are generally less efficient and more labor-intensive than using electricity.

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The surveying equipment used for measuring angles during farm surveying is the theodolite. It is an optical instrument used for measuring both horizontal and vertical angles in surveying. Measuring tape and Gunter's chain are used for measuring distance, while an Abney level is used for measuring slopes and angles.

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The gestation period is the time between conception and parturition, which is the birth of the young animal. In other words, it is the length of time that a developing fetus spends inside the womb before it is born. This period can vary widely among different species of animals, with some taking only a few weeks and others taking many months or even years. It is an important factor in understanding reproductive biology and can help predict when offspring will be born, which can be important for managing breeding programs and caring for pregnant animals.

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Food shortage can be minimized by efficient pest control services. Pests can cause damage to crops, leading to reduced yields and ultimately, food shortages. Efficient pest control measures, such as the use of pesticides, can help to prevent crop damage and increase yields. This can contribute to an increase in the availability of food, and minimize the risk of food shortages. Natural hazards, illegal exportation of farm produce, and hoarding, on the other hand, can contribute to food shortages, and are not effective measures for minimizing them.

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Layers ration contains more limestone than growers ration because limestone supplies sufficient minerals to layers for shell formation. Limestone is a source of calcium, which is essential for eggshell formation in layers. As hens mature and start laying eggs, they require more calcium to produce strong and healthy eggshells. Therefore, layers' feed is formulated to contain higher levels of calcium, usually in the form of limestone, compared to growers' feed. Growers' feed, on the other hand, contains lower levels of calcium because excessive calcium intake in young birds can lead to skeletal problems and deformities. This is because young birds have different nutritional requirements compared to mature layers. In summary, the reason why layers' ration contains more limestone than growers' ration is that limestone supplies sufficient minerals, particularly calcium, for shell formation in mature hens.

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Maize cultivation is a process that involves several necessary operations to ensure a good yield. Among these operations are weeding, thinning, and fertilizer application. However, nursery practices are not necessary operations in maize cultivation. Nursery practices involve the raising of seedlings for transplanting. In maize cultivation, seeds are usually planted directly into the field, and so, nursery practices are not required.

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An increase in supply of agricultural produce can be caused by various factors such as reduced cost of production, favorable weather conditions, and increased demand for the products. However, consumers buying less products is not a factor that can cause an increase in supply of agricultural produce. In fact, if consumers buy less agricultural produce, it can lead to a decrease in demand for the products, which may in turn lead to a decrease in supply. This is because farmers will reduce their production in response to the decrease in demand, in order to avoid surplus production that they may not be able to sell. Therefore, the correct answer is "consumers buying less products". While reduced cost of production, favorable weather conditions, and reduced taxation are factors that can lead to an increase in supply of agricultural produce, a decrease in demand due to consumers buying less products will not cause an increase in supply.

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Tridax (Tridax procumbens) is dispersed by wind. Tridax produces small and light seeds with a hairy pappus that helps them to be carried away by the wind. Other options (pig weed, goat weed, and hausa thorns) are not typically dispersed by wind.

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An advantage of the extensive system of rearing goats is a low labour requirement. Extensive goat farming involves allowing goats to graze and forage freely in natural or semi-natural environments, such as forests, grasslands, or scrublands. This system of rearing goats requires less labour compared to intensive farming, which involves confining goats in pens or sheds and providing them with feed and water. In extensive farming, goats obtain their food from grazing and foraging, which reduces the need for human intervention in feeding and care. This also reduces the cost of labour, making extensive farming a more affordable option for small-scale farmers or those with limited resources. However, it is important to note that extensive farming may have some disadvantages as well. For example, goats may be more exposed to adverse weather conditions and predators, which can affect their health and survival rates. Additionally, the risk of disease transmission may be higher in extensive farming if the goats come into contact with infected animals or environments. In summary, an advantage of the extensive system of rearing goats is the low labour requirement, which can make it a more affordable option for small-scale farmers or those with limited resources.

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Subsistence agriculture is a type of farming that is characterized by small farm holders who rely mainly on their farm produce to meet the basic needs of their families. It involves farming on a small scale, without the use of modern machines and technologies, and with little or no input from external sources such as fertilizers and pesticides. The aim of subsistence agriculture is not to make a profit, but to produce enough food to feed the family and possibly have a surplus to sell or exchange in the local market. Therefore, it is the opposite of large scale production which is focused on producing crops or raising livestock for commercial purposes.

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The answer to the question is option D, "blood-stained diarrhea". Foot and mouth disease is a highly contagious viral disease that affects cloven-hoofed animals such as cattle, pigs, sheep, and goats. The disease is characterized by the presence of sores on the feet, tongue, mouth, and occasionally on the udder. It also leads to excessive production of saliva and lameness, making it difficult for the animals to move. However, blood-stained diarrhea is not a symptom of foot and mouth disease. Instead, it may indicate the presence of other diseases such as bovine viral diarrhea or Johne's disease.

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The correct order for land preparation is land clearing, ploughing, harrowing, and ridging. Land clearing involves removing any trees, stumps, or other debris from the field. Ploughing involves using a plough to loosen and turn over the soil, which helps to bury weeds and other plant material and create a seedbed for planting. Harrowing involves breaking up clumps of soil and smoothing the surface of the field to prepare it for planting. Ridging involves creating raised beds or furrows to help with water management and improve drainage. This order ensures that the soil is properly prepared for planting and provides the best possible growing conditions for crops.

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Rain water is made available to crops through root absorption. When rainwater falls on the soil surface, it percolates into the soil through the tiny spaces between soil particles. As it moves down through the soil, it encounters plant roots which take up the water through a process called root absorption. Root absorption is the process by which water and nutrients are taken up by the roots of a plant. The water moves from an area of high concentration (the soil) to an area of low concentration (the root) through a process called osmosis. As the plant takes up the water, it also absorbs the dissolved nutrients in the soil, which are essential for growth and development. Once the water is absorbed by the roots, it is transported to the leaves of the plant through a system of xylem vessels. The water is then used in photosynthesis and other metabolic processes within the plant. In summary, rainwater is made available to crops through root absorption, which is the process by which water and nutrients are taken up by the roots of a plant. Once absorbed, the water is transported to the leaves of the plant through the xylem vessels and is used in various metabolic processes.

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If urea fertilizer contains 46% nitrogen, then the amount of nitrogen in a 25 kg bag of fertilizer can be calculated as follows: Step 1: Calculate the amount of nitrogen in 1 kg of fertilizer 1 kg of fertilizer contains 46% nitrogen So, the amount of nitrogen in 1 kg of fertilizer = 46/100 * 1 kg = 0.46 kg Step 2: Calculate the amount of nitrogen in 25 kg of fertilizer To calculate the amount of nitrogen in a 25 kg bag of fertilizer, we simply multiply the amount of nitrogen in 1 kg of fertilizer by 25 Amount of nitrogen in 25 kg of fertilizer = 0.46 kg * 25 = 11.5 kg Therefore, there are 11.5 kg of nitrogen in a 25 kg bag of urea fertilizer that contains 46% nitrogen.

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Root-knot disease in tomatoes is caused by a type of microscopic roundworms called nematodes. These nematodes infect the roots of tomato plants and cause the formation of knots or galls, which can limit the plant's ability to take up nutrients and water from the soil. The nematodes that cause root-knot disease in tomatoes are usually Meloidogyne species. They are soil-borne and can persist in the soil for several years, even in the absence of tomato plants. Root-knot disease in tomatoes can cause a range of symptoms, including stunted growth, yellowing of leaves, wilting, and reduced yield. It is a significant threat to tomato production worldwide and can be managed through a combination of cultural, biological, and chemical control measures. Therefore, the correct answer is "nematode". While viruses, bacteria, and fungi can also cause diseases in tomato plants, root-knot disease is specifically caused by nematodes.

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The most common factor affecting land use is population pressure. Population pressure refers to the impact of human population on the available land resources. As the population grows, the demand for land also increases for various purposes like agriculture, housing, industry, and infrastructure development. This often leads to the conversion of natural ecosystems into anthropogenic landscapes, causing habitat destruction, biodiversity loss, and other environmental issues. Population pressure also influences land use through changes in land tenure systems, land-use policies, and market forces. Therefore, it is essential to manage population growth and implement sustainable land-use practices to ensure the long-term productivity and resilience of the land.

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The method that is not a way of improving rangeland is practicing continuous grazing. Continuous grazing refers to allowing animals to graze freely on a pasture or rangeland without any management or control. This can be detrimental to rangeland health as it can lead to overgrazing, soil erosion, and decreased plant diversity. On the other hand, routine and regular weeding, routine reseeding, and regular application of fertilizer are all methods that can help improve rangeland. Weeding involves removing unwanted plants that compete with desirable vegetation for resources such as water and nutrients. Reseeding can help establish and maintain desirable plant species in the rangeland. Fertilizer application can help provide essential nutrients to the soil, which can promote healthy plant growth and increase productivity. Overall, the key to improving rangeland is to use management practices that maintain a balance between animal grazing and rangeland health, such as rotational grazing, resting periods, and monitoring of vegetation and soil health.

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The main objective of agriculture is food production. Agriculture involves the cultivation of crops, rearing of animals, and other activities that produce food for human consumption. The primary aim of agriculture is to ensure there is enough food to feed the growing population. Agriculture is the backbone of food production and plays a crucial role in providing food security. Other objectives of agriculture include income generation, provision of employment, and raw materials for industries. However, the primary objective is to produce food to meet the nutritional needs of the population.

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The method of agricultural extension that aims at reaching a large number of farmers at the same time is the mass method. The mass method involves the dissemination of information to a large number of farmers simultaneously through mass media such as radio, television, newspapers, and mobile phones. This method is useful for reaching a large number of farmers who are scattered over a wide geographical area. The mass method is often used to provide information on new farming techniques, weather forecasts, disease outbreaks, and market prices, among others. By using mass media, extension workers can communicate with farmers in a cost-effective and efficient manner, without the need for face-to-face contact. However, the mass method has some limitations, such as the lack of interaction between the extension worker and the farmers, which can lead to a lack of feedback and understanding of the farmers' needs and challenges. Additionally, the mass method may not be effective for reaching farmers who do not have access to mass media, such as those in remote areas. In summary, the mass method of agricultural extension aims at reaching a large number of farmers at the same time through mass media, such as radio, television, newspapers, and mobile phones. It is a cost-effective and efficient method, but it has some limitations, such as the lack of interaction and feedback from farmers.

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The adult male cattle is called a bull. Bulls are mature male bovines that are used for breeding purposes to produce offspring. They are generally larger and heavier than cows (female cattle) and have more muscular necks, shoulders, and hindquarters. Bulls are also known for their large, curved horns, which they use for defense and dominance displays. In cattle farming, bulls are usually kept separate from the female herd except during breeding season to prevent fighting and injury. Bulls are an important component of the cattle industry and are highly valued for their genetic traits and ability to produce offspring with desirable characteristics.

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Forest management is the process of managing forest resources to meet the needs of present and future generations. It involves balancing the economic, ecological, and social objectives of forest use. One of the options provided is not a problem of forest management. That option is planting different varieties of timber. While it is important to carefully select and manage the species of trees grown in a forest, planting different varieties of timber is not in itself a problem of forest management. The other options listed are all problems that can arise in forest management. For example, the absence of adequate information on the ecosystems in a forest can make it difficult to manage the forest effectively. Inadequate support from the government for the development of forest resources can lead to unsustainable practices and the degradation of forest ecosystems. Indiscriminate destruction of forest resources by bush fires can also have devastating ecological and social impacts. Therefore, the correct answer is "planting different varieties of timber" which is not a problem of forest management.

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The practice of mating closely-related animals is called inbreeding. Inbreeding is the process of mating closely-related individuals, such as siblings or parents and offspring, within the same family or line. The main objective of inbreeding is to enhance the expression of desirable traits or to fix a specific genetic trait in a population. However, inbreeding can also lead to the expression of harmful recessive genes, which can result in reduced performance and fitness of the offspring.

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