Question Library

In Nigeria, the Guinea savanna belt acts as a transition zone, bordering both the rainforests to the south and the Sudan savanna to the north. The Guinea savanna is a broad, transitional ecological zone that stretches across the middle of Nigeria, encompassing a significant portion of the country's land area. To the south, the Guinea savanna transitions into the dense, evergreen rainforests that characterize the coastal regions of Nigeria. As you move north, the Guinea savanna gives way to the Sudan savanna, which is characterized by shorter grasses and a more arid climate.

To estimate plant population size on farmland, you can use the formula: Plant Population density = \(\frac{(population size)}{(Area of habitat)}\) Given: Population density = 5 Area of farmland = 200m x 200m = 40000m\(^2\) Population size = ? Population size = population density x Area of farmland = 40,000 x 5 = 200,000

Secondary succession is faster than primary succession because the soil and some remnants of previous life forms are already present, allowing for quicker recolonization and growth of new species. Primary Succession begins in an area where there is no soil or life, such as a newly formed volcanic island or a glacier retreat area. Pioneer species like lichens and mosses must first colonize the area, break down rock, and create soil, a process that can take hundreds or even thousands of years. Secondary Succession occurs in areas where soil already exists and life previously existed, but has been disrupted by events like fire, storms, or abandonment. Since soil and some remnants of previous ecosystems are already present, the process of recolonization and ecosystem development is much faster, often taking only a few years to decades.

To test for lime (calcium carbonate) in soil, you can use hydrochloric acid (HCl), which reacts with the lime to produce carbon dioxide gas, indicated by fizzing or bubbling. The chemical reaction between lime (calcium carbonate, CaCO\(_3\)) and hydrochloric acid (HCl) is: CaCO\(_3\) + 2HCl → CaCl\(_2\) + CO\(_2\) + H\(_2\)O. In this reaction, calcium chloride (CaCl\(_2\)), carbon dioxide (CO\(_2\)), and water (H\(_2\)O) are produced.

Crop rotation in agriculture is the practice of planting different crops in a planned sequence on the same land, rather than continuously growing the same crop, to improve soil health, manage pests and diseases, and optimize nutrient balance. It helps maintain and improve soil structure, fertility, and organic matter content. Different crops have varying nutrient needs, and rotating them allows for better nutrient cycling and prevents the depletion of specific nutrients in the soil. By optimizing soil health and nutrient availability, crop rotation can lead to higher yields and more productive farming practices.

Recycling, as a solid waste disposal method, is generally unsuitable for organic matter because it's designed primarily for materials that can be reprocessed into new products, while organic waste naturally decomposes and can be managed through composting or other biological processes. Recycling is a highly suitable method for disposing of metal scraps, as it allows for the recovery and reuse of valuable materials, reducing the need for raw materials and minimizing environmental impact. Also, recycling is a suitable and beneficial method for the disposal of plastic waste, offering a way to reuse materials and reduce landfill waste and pollution. Recycling is a highly suitable and effective method for disposing of glass waste, as it allows for the reuse of the material and reduces the need for landfill space and raw materials.

Nuclear energy is a non-renewable energy source because it relies on the finite, naturally occurring element uranium, which is not replenished at a rate that matches its consumption. Non-renewable resources, like fossil fuels (coal, oil, natural gas), are finite and cannot be replenished by natural processes within a human timescale. While nuclear energy is a clean energy source (not producing greenhouse gases like fossil fuels), it's not considered a renewable alternative because the fuel source (uranium) is not replenished naturally.

Two tall parents can have a phenotypically short child if both parents carry a recessive gene for shortness, even though they themselves are tall, and the child inherits two copies of that recessive gene, one from each parent. While genetics play a significant role in determining height, it's not controlled by a single gene, but rather by multiple genes and their interactions. If we use the letters "T" for tall and "t" for short, the parents would be "Tt". The child could have TT (tall), Tt (tall), tT (tall) or tt (short). Kindly note that although genetics are a major factor, other factors like nutrition, hormones, and medical conditions can also influence a child's height.

When a yellow maize is crossed with a white maize and only yellow maize is produced in the first filial generation, the white trait is said to exhibit recessiveness because recessive trait will only be expressed if an maize offspring inherits two copies of the recessive allele. In this case, the white trait is not expressed even though it is there but it is silenced by the dominant trait which is yellow. The reason yellow maize( dominant) was expressed.

The association where one member benefits while the other is relatively unaffected is called commensalism. Commensalism is a type of symbiotic relationship where one species benefits, and the other is neither harmed nor helped. Example:Cattle egrets and cattle are a good example, where the egrets benefit by eating insects stirred up by the cattle, while the cattle are not affected.

Male peacocks display their vibrant, colourful feathers, especially the iridescent tail feathers, as a visual display to attract and impress potential mates, signaling their health and fitness for courtship.

Countershading is a form of camouflage where animals are darker on their upper surfaces (dorsal) and lighter on their lower surfaces (ventral), helping them appear flatter and blend into their environment by canceling out shadows. The darker dorsal coloration absorbs light, while the lighter ventral coloration reflects it, creating a more uniform appearance and minimizing the contrast that would otherwise highlight the animal's shape and shadows. Countershading can also help an animal blend into its environment by matching the color and brightness of the sky above and the darker waters or ground below.

Termite colonies are organized into a caste system with three main groups: workers (foraging and colony maintenance), soldiers (defense), and reproductives (for colony founding and continuation), each with specialized roles. The workers are the most numerous caste and perform various tasks, including foraging for food and tending to the colony, and they feed themselves.

The evidence for a common vertebrate ancestor includes similarities in embryonic development (like gill slits and tails), shared anatomical features, and fossil evidence, all pointing to a shared evolutionary history. Vertebrate embryos, even those of different species, exhibit striking similarities in their early stages, including the presence of gill slits (pharyngeal pouches) and a tail, even if these features are later lost in the adult form. Comparative embryology as a field of study highlights the similarities in the early development of different vertebrate species, suggesting a common ancestor from which these features were inherited. For example, all vertebrate embryos have gill slits and tails, which are later lost in some species, such as humans, where the tail is reduced to the tailbone.

The evidence for a common vertebrate ancestor includes similarities in embryonic development (like gill slits and tails), shared anatomical features, and fossil evidence, all pointing to a shared evolutionary history. Vertebrate embryos, even those of different species, exhibit striking similarities in their early stages, including the presence of gill slits (pharyngeal pouches) and a tail, even if these features are later lost in the adult form. Comparative embryology as a field of study highlights the similarities in the early development of different vertebrate species, suggesting a common ancestor from which these features were inherited. For example, all vertebrate embryos have gill slits and tails, which are later lost in some species, such as humans, where the tail is reduced to the tailbone.