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The sweat gland is a long, coiled, hollow tube of cells. The coiled part in the dermis is where sweat is produced, and the long portion is a duct that connects the gland to the opening or pore on the skin's outer surface. (See diagram above for more explanation.)

The part labelled III is the hair follicle. Hair follicles are dynamic, tube-like structures in the dermis that generate hair, anchor it, and regulate its growth cycle (anagen, catagen, telogen). They are essential for skin repair (healing wounds), producing sebum, acting as sensory receptors for touch, and contributing to thermoregulation. In the context of standard biology examination questions, the hair follicle often specifically referring to the complex that includes the arrector pili muscle, which is associated with the function of pulling the hair upright.

Budding is a form of asexual reproduction common to both Hydra (a multicellular freshwater animal) and yeast (a unicellular fungus). In this process, a small outgrowth or "bud" develops from the parent organism's body. In yeast, this occurs through asymmetric cell division where a new cell bulges from the parent. In Hydra, specialized regenerative cells divide repeatedly at a specific site to form the bud. Once matured, the bud typically detaches to become a new independent individual.

An ecological niche refers to the specific role an organism plays within its environment, including its feeding habits, behavior, and how it utilizes resources. While both insects share the same habitat (the plant), they function differently. Caterpillars are typically leaf-chewers that consume solid plant tissue. On the other hand, Aphids are sap-suckers that use specialized mouthparts to pierce plant tissues and drink phloem sap. Because they utilize different parts of the plant and have different feeding strategies, they occupy distinct niches, which allows them to coexist without direct competition for the same specific resource. A. occupy the same ecological niche: According to the competitive exclusion principle, two species cannot occupy the exact same niche in the same habitat indefinitely; one would eventually outcompete the other. B. be in different habitat: They are living on the same plant, which constitutes their shared habitat. D. be in the same microhabitats: The question specifies they live in different parts of the plant (e.g., one on a leaf, another on a stem or root), meaning they occupy different microhabitats within the larger plant habitat.

Rainfall and relative humidity have a positive relationship, meaning that rainfall increases relative humidity, and relative humidity increases rainfall. Rainwater evaporates into the air, increasing the amount of water vapour in the air. The longer it rains, the more water vapour is added to the air. Consequently, an increase in rainfall only implies the increase emanated from increased relative humidity. Since the ecological zones with high rainfall of 2000 and 2200 are II and III respectively. Option C is the correct answer.

Based on the table provided, Zone I is the most likely to be a desert. Deserts are characterized by extremely low precipitation (rainfall) and high temperatures. Zone I has the highest temperature (45\(^0\)C) and the lowest rainfall (300mm), matching typical desert characteristics better than the other, wetter, or cooler options.

The relationship between termites and the cellulose-digesting protozoans in their guts is a classic example of mutualism, specifically obligative mutualism, because both organisms benefit and cannot survive without each other. Termites eat wood but lack the enzymes to digest cellulose. The protozoans in their hindgut break down the cellulose into simple sugars that the termite can absorb and use for energy. While, the termite provides the protozoans with a stable, protective environment and a constant supply of wood particles (food).

According to the 10% rule, only about 10% of the energy from one trophic level is transferred to the next. The remaining 90% is lost primarily as heat during respiration or through indigestible matter and waste. Because energy is required to build and maintain living tissue, the progressive loss of available energy limits the total biomass (the total mass of living organisms) that can be supported at higher levels. Consequently, there is significantly less biomass at the top of the food chain than at the bottom.

Reptiles are highly adapted to terrestrial life, and one of their primary mechanisms for surviving in dry environments is the prevention of desiccation (water loss through the skin). This is achieved through the presence of keratinous scales, which are tough, overlapping structures made of the protein keratin. These scales create a waterproof barrier that minimizes the evaporation of internal body fluids, allowing reptiles to thrive in arid habitats where water is scarce.

Katsina State is one of the "frontline states" in Nigeria, which are highly susceptible to desert encroachment due to their location in the arid/semi-arid region bordering the Sahara Desert. While Kaduna, Taraba, and Kwara are further south and less prone, Katsina faces significant land degradation and desertification.

Scarcity of food leads to a sudden decrease in population primarily because it results in malnutrition, starvation, and eventually death among the affected organisms. In biological and ecological terms, when the demand for food exceeds the available supply, it limits the carrying capacity of the environment, causing a rapid increase in the mortality rate as individuals fail to survive without sufficient energy and nutrients. While other factors like reproduction and migration are affected over time, a "sudden" decline is most directly driven by the deaths of the existing population.

Clayey soil is difficult to plough in the rainy season because it becomes puddled and sticky when wet, making it hard to break up and turn over with a plough.

Continuous cropping is the practice of growing the same type of crop on the same piece of land year after year without allowing the soil to rest or recover. This method leads to a significant loss of soil fertility because it repeatedly removes the same specific nutrients from the soil, eventually exhausting its natural reserves(Depletion of nutrient). Unlike fallowing or rotation, it provides no time for natural biological processes or organic matter decomposition to restore nutrient levels. It often involves intensive tillage and removal of crop residues, which can increase soil erosion and degrade soil structure.

DNA analysis (also known as DNA fingerprinting or profiling) is the most accurate method for resolving paternity disputes. It compares specific genetic markers between the child and the alleged father. Because a child inherits exactly 50% of their DNA from each biological parent, this method can provide results with an accuracy rating of 99.9% or higher for inclusion and 100% for exclusion.

In four o'clock plants (Mirabilis jalapa), flower color inheritance is a classic example of incomplete dominance. In this pattern of inheritance, neither allele is completely dominant over the other. When a homozygous red variety (RR) is crossed with a homozygous white variety (rr or WW), the resulting F1 generation is heterozygous (Rr or RW). Because the red pigment is diluted rather than fully expressed or completely masked, the flowers exhibit an intermediate phenotype, which is pink. A. white: This would only occur if white were the completely dominant trait or if both parents were white. B. red: This would occur in a standard Mendelian cross where red is completely dominant over white. D. multicoloured: This phenotype (such as spots or splotches) is characteristic of codominance, where both parental traits are expressed simultaneously and distinctly, rather than blending.