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Oviparous animals are those that reproduce by laying eggs. They include animals like birds, most reptiles, most amphibians, most fishes. Viviparous animals are the animals that give birth directly to their kind. These individuals grow up and live. Oviparous animals are animals that do not give birth to their kind. Instead, they lay eggs that are either fertilised or unfertilised. Ovoviviparous means producing eggs that hatch inside the mother's body, rather than being laid outside. It's a reproductive strategy that's seen in some fishes and reptiles.

Amplexus defines the mating position of frogs and toads, in which the male clasps the female about the back. Amplexus is a type of mating behavior exhibited by some externally fertilizing species in which a male grasps a female with his front legs as part of the mating process, and at the same time or with some time delay, he fertilizes the eggs as they are released from the female's body. "Mating" refers to the general act of sexual reproduction between two organisms, while "amplexus" is a specific mating posture used by frogs where the male clasps onto the female's back, aligning their cloacae to facilitate external fertilization; essentially, amplexus is a type of mating behavior unique to frogs, focused on positioning for egg fertilization, rather than the broader term of mating itself.

Charles Darwin was one of the first to scientifically document that roots show positive gravitropism and stems show negative gravitropism. That is, roots grow in the direction of gravitational pull (i.e., downward) and stems grow in the opposite direction (i.e., upwards).

Abscisic acid (ABA) is found in the roots and leaves of plants, including seedlings. ABA is a plant hormone that helps plants respond to environmental stress and developmental processes. Ascorbic acid, also known as vitamin C, is found in all cell compartments of plants, including the cell wall, chloroplasts, and cytosol. Ethylene is found in all parts of a plant, including seedlings. Auxin alters the plant wall plasticity making it easier for the plant to grow upwards. Auxin is a plant hormone found in the roots of seedlings. Auxin is produced in the tips of the roots and shoots, and it can diffuse to other parts of the plant.

The nucleus of a cell contains DNA, which is the organelle responsible for heredity. The nucleus is the cell's command center, controlling the cell's growth, division, and other functions.

The part labelled I is the cell wall(See digram above).

The part labelled I is the cell wall(See digram above).

The cumulative frequency 5\(\leq\) x \(\leq\) 12 = 10 + 12 + 10 + 8 + 6 + 8 + 10 + 8 = 72

\(\begin{pmatrix}3 & -2 \\ -7 & 5 \end{pmatrix} + 2 \begin{pmatrix}-2 & 4 \\ 3 & -1 \end{pmatrix}\) \(2 \begin{pmatrix}-2 & 4 \\ 3 & -1 \end{pmatrix} = \begin{pmatrix}2 \cdot -2 & 2 \cdot 4 \\ 2 \cdot 3 & 2 \cdot -1\end{pmatrix} = \begin{pmatrix}-4 & 8 \\ 6 & -2\end{pmatrix}\) \(\begin{pmatrix}3 & -2 \\ -7 & 5 \end{pmatrix} + \begin{pmatrix}-4 & 8 \\ 6 & -2\end{pmatrix} = \begin{pmatrix}3 + (-4) & -2 + 8 \\ -7 + 6 & 5 + (-2)\end{pmatrix}\) \(= \begin{pmatrix}-1 & 6 \\ -1 & 3\end{pmatrix}\) Thus, the final result is: \(\begin{pmatrix}-1 & 6 \\ -1 & 3\end{pmatrix}\)

I = \(\begin{pmatrix}1 & 0 \\0 & 1 \end{pmatrix}\) Then, 3x - 2I becomes 3p - 2I (since we are finding f(p)) 3\(\begin{pmatrix}2 & 1 \\-1 & 0 \end{pmatrix}\) - 2\(\begin{pmatrix}1 & 0 \\ 0 & 1 \end{pmatrix}\) = \(\begin{pmatrix}6 & 3 \\-3 & 0 \end{pmatrix}\) - \(\begin{pmatrix}2 & 0 \\ 0 & 2 \end{pmatrix}\) = \(\begin{pmatrix}4 & 3 \\-3 & -2 \end{pmatrix}\)

(a) The Characteristic Features of the Vegetation of Tropical rain forest are as follows: (i)Vegetation divided into 5 layers/strata. (ii) Ground layer of non-woody Oviduct plants/I ichens/fernsigrasses. (iii) Lower layer of shade-loving dwarf/tree/palms/ shrubs. (iv) Middle layer of small trees with Funnel I elongated narrow crowns. (v) Upper layer oviduct Ovary of tall trees whose crowns form a continuous canopy. (vi) The emergent trees come Uterus above the canopy at intervals, (vii) The forest is very rich is species. (viii) Trees Cervix have straight/slender trunks with branches mostly near the top. (ix) Most of the trees are evergreen. (x) Most of the trees have Vagina buttress and prop roots that support tall stems. (xi) The leaves of the trees tend to be broad. (xii) The flowers of these trees Vulva are usually small. (xiii) Epiphytes, climbers and parasitic plants are numerous and form close associations with the dominant plants. (xiv) Epiphytes have adaptations for storing water and absorbing moisture from the air. (b) Types of Savannah and area(s) or town(s) found: Guinea Savannah (h) - Kaduna, florin, Bida. Sahel Savannah (h) - Maiduguri . Sudan Savannah (h) - Kano, Borno, Sokoto, Gongola, Bauchi. (c)(i) The ways by which animals in arid habitat are adapted to droughts and high temperature are: (1) Use of metabolic water. (2) Production of concentrated water/urine. (3) Living in burrows/hibernation. (4)Thick scales/ skin to prevent water loss by evaporation. (ii) High temperature: (1) Seeking shade to keep cool. (2) Nocturnal life. (3) Living in burrows/underground tunnels where temperature is low. (4) Restricting activities to cooler periods.

(a) Difference between tropic movement and nastic movement Tropic movement Nastic movement It is a growth movement not a growth movement Response to unilateral stimulus response to diffuse stimulus Slow response Fast response Not reversible Reversible Not due to cell tugor Due to changes in cell tugor Directional/positive /negative response positive nor negative response (b) How light brings about tropic movement in stem and root of a flowering plant: (i) When unilateral light falls on the stem, the auxin/growth hormone/IAA is displaced from the lighted to the dark side. (ii) The increase in auxin concentration on the dark side increases growth on that side causing the stem to bend towards the light/positive phototropism. Roots: (i) The auxin is displaced from the lighted side to the dark side. (ii) The increase in auxin concentration retards growth on the dark side causing the root to bend away from the light/negative phototropism. (c) The following would be observed when a growing seedling is placed horizontally: (i) Shoot bends upwards, showing negative geotropism/positive phototropism. (ii) Root bends downwards, showing positive geotropism/negative phototropism. (d) Functions of the Pituitary gland: (i) Stimulates growth/growth of long bones/cell division. (ii) Stimulates production of sex-hormones/named sex hormones. (iii) Stimulates production of anti-diuretic hormone/ADH/regulation of water re-absorption in the kidney/osmos regulation. (iv) Produces hormones which control other endocrine glands/stimulates thyroid gland/adrenal cortex. (v) Stimulates protein synthesis. (vi) Induces birth by contraction of uterine muscles/production of oxytoxin. (vii) Induces milk secretion/produces prolactin. (viii) Controls egg and sperm production. (e) Differences between growth in plants and animals: Growth in plants Growth in animals Unlimited growth/growth through out life limited growth/growth stops after a period of time No fixed number of organs fixed numbers of organs (e.g two eyes,ears etc) limited to specific region not restricted/intercalary

(a) Balanced Diet; is a diet containing all the six food classes/types of food in the right proportion to meet the body's requirement for growth, repair and maintenance. (b) Classes of food: -Protein -Carbohydrate -Vitamins -Water -Mineral salts/nutrients -Fats and Oils/Lipids. Importance of food classes Food substances Importance Carbohydrate Energy giving protein Growth/replacement/repair of worn out cells/repair of tissues Fats and oil Energy source/formation of adipose tissue for insulation Vitamins for proper functioning/maintenance of the body Mineral salts/nutrients play specific roles in metabolic processes/maintenance of the body water Medium for various metabolic processes/named processes (c) The source, substrate and end products of ptyalin, pepsin and lipase are tabulated below: Enzyme Source Substrate End product Pytalin Salivary gland cooked starch maltose pepsin Gastric gland protein peptones/polypeptides/peptides Lipase pancrease fat/oils/lipids fatty acids and glycerol

(a)(i) Genes; are hereditary units/materials located on the chromosomes through which characters are transmitted from parents to offspring. (ii) Gene mutation; is a spontaneous/sudden/unpredictable change in an individual gene which is persistent/ permanent/irreversible/heritable. (b) The structures in plants and animals where mitosis and meiosis take place are listed below: (i) Mitosis in plants: Root tip/stem apex; stem tip/ apex; cambium; meristems. Mitosis in animals: Skin; damaged tissue; bone marrow; somatic cells/ wounded area of the body (e.g. skin). (ii) Meiosis in plants: Ovaries; anthers. Meiosis in animals: Ovaries; testes. (c) Advantages of cross breeding two different breeds of cows are: (i) Increased milk production. (ii) Increased meat production/improved weight. (iii) Resistance to diseases in the offspring. (iv) Early maturity. (v) Increased fecundity/reproductive capacity. (d) Applications of genetics to medicine: (i) Prevention of hereditary diseases. (ii) Determination of the paternity of a child by use of DNN blood group. (iii) Blood transfusion. (iv) Production of insulin (to treat diabetes).

(a)(i) Pollution; is the discharge of harmful/toxic substances into the environment in quantities which are harmful to life as a result of the activities of humans. (ii) Pollutants of water: - (i) Domestic waste/sewage/household waste. (ii) Industrial waste/dyes/detergents/lead/mercury compounds. (iii) Agricultural wastes/pesticides/insecticides/fertilizers. (iv) Oil/oil spillage. (v) Hot water/thermal plants. (b) Effects of pollutants on aquatic organisms Domestic wastes: (i) Bacterial breakdown of sewage reduces dissolved oxygen in water/eutrophication. (ii) Aquatic animals suffocate and die. (iii) Rapid growth of aquatic plants due to mineral rich sewage. (iv) Reduces light penetration and photosynthesis. (v) Contaminated sewage spread disease-causing organism. Industrial wastes: (i) They are poisonous to aquatic organisms. (ii) Detergents form foam on the water surface tension causing floating animals to sink. (iii) Phosphates cause rapid plant growth. (iv) Dyes from textile factories reduce light penetration/photosynthesis. Agricultural wastes: (i) These may accumulate to toxic levels thereby poisoning aquatic organism. (ii) Fertilizer residues stimulate growth of aquatic plants which form a dense mat on the surface of the water leading to depletion of oxygen/eutrophication reduction of light penetration resulting in decrease in the rate of photosynthesis and causing death of aquatic organisms. Oil Spillage: (i) Oil reduces surface tension of water causing floating animals to sink. (ii) Animals die from lack of oxygen. (iii) Coats feathers/fur of animals making them unable to fly/causing affected animals to freeze/starve to death. (iv) Coats gills/filters of aquatic organism. (v) Reduces light penetration and decrease photosynthesis. (vi) Toxic to aquatic organisms. Hot water: (i) Kills living organisms. (ii) Upsets the balance of the ecosystem. (iii) Hot water increases the water temperature thereby reducing the oxygen content and leading to death.