Agricultural Science 2021 Jamb Examination

Edaphic factors are related to the soil and its properties, such as soil type, structure, pH, and mineral content. Rocks, soil, and topography all influence soil formation and plant growth, making them edaphic factors. Storm, however, is a climatic or atmospheric factor rather than a soil-related one.
Therefore, storm is not an edaphic factor.

Bee farming involves the rearing of bees mainly for honey, wax, and pollination services. This practice is known as apiculture. Heliculture refers to snail farming, forestry is the management of forests, and agronomy deals with crop production and soil management.
Hence, apiculture is the correct term for bee farming.

Entomology is the branch of zoology that deals with the study of insects, including those that damage crops. Pathology concerns the study of diseases, agronomy focuses on crop production, and synecology studies relationships among communities of organisms.
Therefore, entomology correctly describes the study of insect pests of crops.

Metamorphic rocks are formed when existing rocks undergo changes due to high heat, pressure, or chemical processes. They are usually hard and massive, and some may occur in layers. Fossils, however, are rarely found in metamorphic rocks because the heat and pressure involved in their formation destroy organic remains.
Thus, the presence of fossils is not a characteristic of metamorphic rocks.

IITA stands for International Institute of Tropical Agriculture. It is a research organisation based in Ibadan, Nigeria, focusing on improving food security and agricultural sustainability in tropical regions.
Other options are incorrect because they either alter the official name or refer to non-existent institutions.

Igneous rocks are formed when molten magma or lava cools and solidifies. They are the primary rocks from which other rock types can form. Metamorphic rocks arise from existing rocks subjected to heat and pressure, while sedimentary rocks result from the accumulation of sediments. 'Caleima rock' is not a recognised rock type.
Hence, the correct answer is igneous rock.

Earthworms are considered farmers' friends because they aerate the soil, improve its structure, and enhance fertility through their burrowing and feeding activities. Aphids and grasshoppers are crop pests, and termites can damage wooden structures and roots.
Therefore, the earthworm is rightly regarded as a friend of the farmer.

Planktons are tiny organisms, both plant (phytoplankton) and animal (zooplankton), that float in water and serve as the primary source of food for many aquatic animals, including fish. Rotten leaves and algae may contribute organic matter, but they are not the main food source.
Hence, fishes mainly feed on planktons in rivers.

Depreciation per year is calculated as Annual Depreciation:\[ \text{A_D} = \dfrac{\text{Cost Price} - \text{Selling Price}}{\text{Number of Years}} \]Substituting the values:\[ = \dfrac{12500 - 4300}{4} = \dfrac{8200}{4} = 2050 \]Therefore, the annual depreciation is \₦2,050.

Climate refers to the long-term average pattern of weather elements such as temperature, rainfall, humidity, and wind of a region, typically measured over 30 years or more. Weather, on the other hand, describes the short-term atmospheric conditions.
Hence, the average weather condition of a place over time is known as climate.