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(a)(i) Disease: A condition in which the normal functions of an organism/part of the body/cell/tissue/organ is impaired/disturbed. (ii) Symptom: Any observable effect on an organism: Caused by the presence and irritation of a disease-causing agent/pathogen. (b)(i) Physical barriers: (i) Skin (ii) Hairs (iii) Cuticle (iv) Epidermis (v) Bark (vi) Cell wall lining. Chemical barriers: (i) Mucus (ii) Saliva (iii) Tears (iv) Gastric/ HCL and intestinal secretions (v) Phenolic compound (vi) Gums (vii) Tannins (viii) Wax (ix) Oily secretions! sebum (ii) How vaccination protects the body: The vaccine/attenuated pathogen is administered into the body. The body responds by producing copious antibodies. The next time the body is exposed to the same antigen/infection/pathogen antigen, the memory cells allow a more rapid and heightened/vigorous response to antibody production. Protection of the body against future infections. (c) Differences between antibodies and antigens (I) Antibodies is a protein molecule. Antigens May not be a protein molecule (ii) Antibodies is Produced in response to a particular foreign substance/antigen while antigens Stimulates formation of antibodies (iii) Antibodies Usually found in the plasma fluid of the blood,antigens are Usually produced in/introduced into the body. (iv) Antibodies are Protective in functions, antigens Leads to an immune response/immunity. (d) Causative Agent: (i) Malaria: Plasmodium vivax/Plasmodium/malaria/species (ii) Cholera: Vibrio cholera. (ii) AIDS: Human Immuno-deficiency virus/HIV

(a)(i) Description of Epigeal Germination: (i) Seed absorbs/imbibes water and swells. (ii) Testa splits and the radicle emerges. (iii) The hypocotyl of the germinating seed elongates. (iv) Pushing the seed out of the soil. (v) The cotyledon(s) become exposed to sunlight. (vi) Turns green to photosynthesize. (vii) The plumule develops into a green shoot. (viii) The cotyledon(s) dry up/shrink and fall off. (ii) Differences between epigeal and hypogeal germination: Epigeal germination Hypogeal germination Hypocotyl elongates Epicotyl elongates cotyledon cotyledon remains in the soil cotyledon(s) turns green / photosynthesize cotyledon does not photosynthesize plumule does not emerge simultaneously with the radicle plumule emerges simultaneously with radicle Energy with the radicle from cotyledon energy derived from endosperm (b)(i) Seed dormancy: An inactive period of a seed.. During which growth slows/completely ceases. Due to certain internal or external factors. (ii) Ways of breaking dormancy: Removal/corrosion of testa. Treatment of seed with acid/digestive enzymes/water. Exposure to alternating high and low temperature. Addition of dormancy-breaking hormones/named hormones. Exposure to fire. Exposure to light. (c) Advantages of using contraceptives in human population: (i) It controls birth rate. (ii) Reduces over-population. (iii) Promotes maternal health/reduces maternal death. (iv) Promotes infant survival rate. (v) Enables parents to determine family size. (vi) Prevents unwanted pregnancy. (vii) Enhances good standard of living for the family. (viii) Some prevent STI or STDs.

(a)(i) Mode of nutrition of Specimen D- Parasitic (ii) One economic importance of each Specimen C, D and E. Specimen C/Grain Weevil: They destroy grains/reduce their food quality. Increase production cost for farmers. Therefore lowers the farmers income. Specimen D/Tick: They infest cattle/dogs/suck blood thereby making them anemic; and reduce meat quality. They transmit diseases. They decrease resistance to diseases in cattle/dog. Specimen E/Rat: They destroy stored food items/contamination of food. They spread diseases. (b)(i) Classification of Specimen Phylum Class C Arthropoda Insecta D Arthropoda Arachnida E Chordata Mammalia (ii) Observable characteristics: Class insecta/ Specimen C: Three body divisions/head, thorax and abdomen. Presence of 6 jointed/'3 pairs of jointed walking legs; presence of compound eyes. Presence of segmented thorax/prothorax, mesothorax and metathorax. Presence of wings. Presence of body divisions/Cephalothorax and abdomen. Presence of simple eyes/ocelli Presence of two appendages for feeding/pedipalps and chelicera. Class mammalian/specimen E : Presence of hair/fur on body. Presence of external ears/pinnae. Presence of mammary glands. The presence of four limbs for locomotion. Heterodont dentition. (III) Observable differences between C& D: C/Grain Weevil D/Tick Three body division/head, thorax and abdomen Two body divisions/cephalothorax and abdomen 3 pairs of legs/6 legs 4 pairs of legs/8 legs Compound eyes Simple eye present Presence of wings Absence of wings Distinct tnorax / thorax present Thorax fused with head/cephalothorax Presence of antennae Absence of antennae (c) Observable features of Specimen E/Mammalia that are sensory in nature. (i) external ears/pinnae (ii) Skin/fur (iii) Whiskers (iv) Eyes (v) Nostrils (vi) Tail

(a) Class of Specimen J-Tilapia: Osteichthyes. Reason: Body is covered with scales. (ii) Presence of paired fins. (iii) Presence of lateral line(s). (iv) Presence of operculum/gill cover. class of Specimen K/Toad: Amphibian Reason: (i) Presence or warty skin. (ii) Presence or webbed digits. (iii) Presence of moist skin. (iv) Presence of bulging eyes. (v) Presence of ear drum. Structural adaptations for escaping predation: Specimen K/Toad:Presence of poison gland on skin which secretes a substance which irritates/repels the predators. (i) Counter shading of the dorsal and ventral sides/camouflage facilitate escape from predator. (ii)Long hind limb and short muscular forelimb ror jumping away from predator. Class of Specimen L/Lizard : Reptilla Reason: Presence of dry horny scales on skin (ii) presence of fore and hind limbs with clawed digits. (iii) Homodont dentition. (iv) Well developed retractable tongue. Specimen L/Lizard:Detachable tail to escape from predators. (ii) Skin color blends with surrounding/camouflage to enhance escape from predators. (iii) Eyes for seeing predators. (iv) Limbs for running away from predators. (c) Drawing Specimen J/Tilapia: (d)(i) Similarities between Specimen J& L: (i) Presence of eyes. (i) Presence of nostrils. (ii) Presence Or Scales. (v) Presence of head. (v) Presence of tail. Differences (ii) J/Tilapia L/Lizard Presence of fins Presence of limbs Absence of tympanum Presence of tympanum Lateral line present Lateral line absent Short tail Long tail Presence of operculum/gill cover No operculum/gill cover

mn - nq - n\(^2\) + mq mn - n\(^2\) - nq + mq (mn - n\(^2\)) (mq - nq) n(m - n) + q(m - n) = (n +q) (m - n)

(a)(i) < PTS = 38^\circ (alternate angle) 42^\circ + x + 38^\circ = 180^\circ (angles on a straight line) 80^\circ + x = 180^\circ x = 180^\circ - 80^\circ = 100^\circ (ii) < SQT = 42^\circ (alternate angle) < SQR = 60^\circ (sum of angles in a triangle) y + 42^\circ + 60^\circ = 180^\circ (angle on a straight line) y + 102^\circ = 180^\circ y = 180^\circ - 102^\circ = 78^\circ (b) \(< QSP = \frac{150}{2}\) (angle at the centre is twicw angle at the circumference) \(< QSP = 75^\circ\) \(\hat{R} + \hat{P} = 180^\circ\) (opposite angles in a cyclic quad are supplementary) \(\hat{P} + 75^\circ + 45^\circ = 180^\circ\) (sum of angle in a triangle) \(\hat{P} = 180^\circ - 120^\circ\) \(\hat{P} = 60^\circ\) \(\hat{R} + \hat{P} = 180^\circ\) \(\hat{R} = 180^\circ - 60^\circ\) \(\hat{R} = 120^\circ\) \(< RQS + < QRS + < QSR = 180^\circ\) (sum of angle in a triangle) \(< RQS = 180^\circ - (40^\circ + 120^\circ)\) = \(180^\circ - 160^\circ\) \(< RQS = 20^\circ\)

x2 + 2x > 15 x2 + 2x - 15 > 0 (x2 + 5x) - (3x - 15) > 0 x(x + 5) - 3(x + 5) >0 (x - 3)(x + 5) > 0 therefore, x = 3 or -5 i.e. x< 3 or x > -5

volume of rectangular container = L x B x H 1 litre = 1000cm3 96 litres = \(\frac{1000cm^3}{1 litres}\) x 96 litres volume = 96000cm3 96000 = 220 x 40 x 11 96--- = 8800H H = \(\frac{96000}{8800}\) = 10.97cm = 11cm

All electromagnetic waves: are transverse waves; can travel through a vacuum ; travel at exactly the same speed in a vacuum, the speed of light, 300,000,000 m/s. The common designations are radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV) light, X-rays and gamma-rays. ultraviolet rays lie beside violet of visible light and has a lesser frequency than visible light.

Phenolphthalein is one of the most commonly-used indicators in neutralisation titration. Phenolphthalein is naturally colorless but turns pink in alkaline solutions.

Deliquescent substances are referred to known as those substances which absorbs moisture from the surrounding and dissolves themselves with the moisture or water to form a solution. Examples are sodium hydroxide(NaOH), calcium chloride(CaCl2), potassium hydroxide(KOH), ammonium chloride(NH4Cl) , etc

Chlorine(Cl) has configuration 2,8,7 but Chlorine ion (Cl-) has 18 electrons and configuration 2,8,8. Here is the reason: Chlorine has 17 electrons, and these are distributed in shells (or energy levels) as follows: 2 in the first shell, 8 in the second, and 7 in the third.This is represented as 2,8 7. Chlorine can gain one electron to achieve a stable electron configuration, resembling that of the noble gas Argon. When chlorine gains an electron, its electron configuration becomes 2, 8, 8, making it a chloride ion (Cl⁻). The 2,8,8 configuration means the outermost shell is full with 8 electrons, which is the octet rule, making the ion stable.

2q35 = 778 2 x 52 + q x 51 + 3 x 50 = 7 x 81 + 7 x 80 2 x 25 + q x 5 + 3 x 1 = 7 x 8 + 7 x 1 50 + 5q + 3 = 56 + 7 5q = 63 - 53 q = \(\frac{10}{5}\) q = 2

\(\frac{3\frac{2}{3} \times \frac{5}{6} \times \frac{2}{3}}{\frac{11}{15} \times \frac{3}{4} \times \frac{2}{27}}\) \(\frac{\frac{11}{3} \times \frac{5}{6} \times \frac{2}{3}}{\frac{11}{15} \times \frac{3}{4} \times \frac{2}{27}}\) \(\frac{110}{54} \div \frac{66}{1620}\) 50

S.I. = \(\frac{P \times R \times T}{100}\) If T = 9 months, it is equivalent to \(\frac{9}{12}\) years S.I. = \(\frac{5000 \times 4 \times 9}{100 \times 12}\) S.I. = N150