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The part labelled I are the nitrogenous bases usually held together by hydrogen bonds. (See diagram above for reference)

Geographical selection, in the context of evolution, refers to the process where populations of the same species become separated by physical barriers, leading to the development of distinct species over time due to adaptation to different environments. Predation is a biological interaction where one organism (the predator) kills and consumes another organism (the prey) for food. interaction between two different organisms living in close physical association, typically to the advantage of both. The change in the length of giraffes' necks is primarily attributed to natural selection, where individuals with slightly longer necks had a survival advantage, allowing them to reach higher food sources and reproduce more successfully, thus passing on their longer neck genes - Charles Darwin

The elongated neck of a giraffe is a clear example of a morphological adaptation, as it's a physical characteristic that allows them to reach high-up foliage for food and also helps with visual vigilance.

Larva can have both positive and negative economic impacts, as they can be a vital food source for some while also being agricultural pests that damage crops. Some larva are edible and provide a source of protein and nutrients for humans and animals. On the other hand, larva can consume leaves and other plant parts, potentially damaging crops and reducing yields. In the context of the manner in which the question was asked, the negative economic impact is actually what the examiner intended. Thus, option D is the correct answer.

The adaptation shown by a larva on plant leaves is most likely disruptive coloration, where the larva's coloration breaks up its outline, making it harder for predators to spot. Many insects, like butterflies and caterpillars, use disruptive coloration to blend in with leaves, twigs, or other parts of their environment.

The maxillary palp labelled iv: - Small antenna-like sensory appendage emerging from the maxilla. - These palps serve as organs of touch and taste in feeding and in the inspection of potential foods and/or prey.

Insect antennae are sensitive to touch, air movement, heat, vibration (sound), and especially smell or taste. Insect antennae are highly sensitive to both touch and chemicals, serving as their primary sensory organs for detecting environmental stimuli like odors, vibrations, and even humidity.

The unique feature that distinguishes chickens (and birds in general) from other vertebrates is their covering of feathers. Feathers provide insulation and temperature regulation, Support and protection during flight, Camouflage and display for communication and mating. Feathers are a characteristic that sets birds apart from other vertebrates, such as mammals, reptiles, and amphibians.

Birds use both their beaks as well as their limbs for offense and defense against predators.

Species I thrives under conditions of moderate to high rainfall because as rainfall gradually increases, the number of organisms increases as well. Specie II is not only found in locations where it rains all year round because even at point zero where there was no rainfall, the number of the organisms remained at 200/km\(^2\). Species III decreases in number as rainfall increases, which means increase in rainfall does not favour them. Species IV increases in number gradually as rainfall increases, got to a peak and started decreasing in number again which means its distribution is dependent on rainfall. Therefore, the correct option is D.

The distribution of Species II is not affected by rainfall because as the rate of rainfall increases, the number of organisms remained constant at 200. Hence, the distribution of species II are not affected by rainfall.

In the symbiotic relationship between fungal hyphae and algae, fungi benefit from the algae's photosynthetic activity, gaining access to sugars (food) produced by the algae, while the algae are protected and can access nutrients from the fungal hyphae. The algae provides the fungus with carbohydrates (energy) and oxygen, while the fungus provides the algae with water and minerals.

The relationship between fungal hyphae and algal plants in lichens is a mutualistic symbiosis, where both organisms benefit from the interaction. The algae (or cyanobacteria) provide food through photosynthesis, while the fungus offers protection and resources.

The correct answer is A - Check desert encroachment. The Sahel region is a transition zone between the Sahara Desert and the savannas to the south, and is vulnerable to desertification. Shelter belts, also known as windbreaks or green belts, are established in the Sahel region to prevent desertification and sand dune encroachment, reduce soil erosion and degradation,protect crops and livestock from harsh winds and sandstorms, and help maintain soil fertility and biodiversity. The other options are not the primary purpose of establishing shelter belts: - Providing wood fuel (B) may be a secondary benefit, but not the main purpose. - Beautifying the region (C) is not a primary goal, although shelter belts can have aesthetic benefits. - Breaking the harmattan wind (D) is a benefit, but not the main purpose. The harmattan is a dry, dusty wind that blows from the Sahara during the winter months.

If 13m + 24m = 41m 1 * m1 + 3 0 + 2 * m1 + 4 * m0 = 4 * m1 + 1 * m0 1 * m + 3 * 1 + 2 * m + 4 * 1 = 4 * m + 1 * 1 m + 3 + 2m + 4 = 4m + 1 3m + 7 = 4m + 1 4m -3m = 7 - 1 m = 6