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(a) The process of perceiving smell Chemical substances/odour carried in the air pass through the air/nasal cavity The molecules dissolve in the moist membrane of the nasal cavity Sensory cells are stimulated Impulses are formed which pass through the nerves ending to the olfactory nerves which pass into the cerebrum of the brain/brain The brain interprets the impulses And the sensation of smell is produced/smell is perceived (b)Adaptive features of the egg of a domestic fowl; Porous: shell; for gaseous exchange/provides shelter/ protects the embryo against mechanical damage/ desiccation Shell membranes; allow gaseous exchange/for protection Yolk; contains high level of proteins and fats/provides food for embryonic-growth Egg white/albumen; consists of water to absorb shock/ proteins/food Air space; provides surface for gaseous exchange Chalaza; holds the yolk/embryo in position. (c)i. Autotrophs: Organisms that do not rely on other organisms for food/they manufacture their own food; from using simple inorganic compounds; can be chernosyn-thetic/photosynthetic ii. Examples of unicellular autotrophs Clamydomonas; Euglena; chemosynthetic; bacteria/ sulphur, bacteria; blue-green; algae/Anabaena; Nostoc/ Oscillatoria; Chlorella diatoms; Nitrosomonas; Nitrobacteria (d) Functions of WHO provides grants for medical research Improves public health/promotes environmental health prevents the spread of diseases vaccination provides vaccines/drugs in cases of emergencies Informs/creates awareness/educates the public of any research findings/outbreak of diseases Assists by sending medical personnel/logistical sup-port to countries upon request Helps in the training of medical personnel keeps health statistics promotes nutritional/sanitary products. (e) Examples of plants and animals that live in fresh water pond Plants: Water arum; diatoms; Ceratophyllum/hornwort; utricularia/bladderwort. Arrowhead/sedge; Pistia; Salvinia/water fern; water lily; wolffish/duckweed any other correctly. Animals: Cyclops; Daphnia/water flea; Hippopotamus; crocodile; water snake; tadpoles; pond skaters; zooplanktons; mosquito larvae; water bugs; water scorpions; leeches; water snails; catfish/Tilapia fishes etc. (f) Differences between skin of a mammal and epidermis of leaf skin of a mammal Epidermis of leaf skin is made up of many layers/cells made up of a single layer/cells presence of sweat gland absence of sweat gland presence of sebaceous gland absence of sebaceous gland Absence of cuticle presence of cuticle Absence of guard cell stomata Guard cells are present / stomata Has blood cells capillaries absence of blood vessels / capillaries synthesizes vitamin D does not make vitamin D Fatty cells are present absence of fatty cells It is a sensory organ its not a sensory organ Hair follicle present hair follicle absent erector muscle present erector muscle absent presence of sweat pore absence of sweat pore (g) Type of competition on (i) Plot A: intra specific/intra species competition (ii) Plot B: interspecific/interspecies competition

The first stage of incomplete metamorphosis is the egg. During this time, the insect will hatch into a form called a nymph. The nymph is basically a small version of the adult insect.

(a) (i)Phylum of specimen R/Earthworm Annelida. (ii) Reasons for the classification of specimen R/Earthworm: -presence of metameric segmentation/segments are separated from each other (by septa) -they are bilaterally symmetrical -segments are separated from each other -presence of chaetae - body is covered by thin collagen cuticle body is long cylindrical. Habitat of specimen R/Earthworm: (i) -under decaying leaves -wet/moist soil -in open savanna/savannah beneath the tall grasses - in the forests in decaying tree-stumps. (i) Features of adaptation of specimen R/Earthworm (b) -bristle-like chaetae/seatae for locomotion moist skin for gaseous exchange -pointed anterior for burrowing into the soil slimy body reduces friction during movement -clitellum for attachment during exchange of sperms/reproduction/ secretes cocoon (in which its legs are deposited. (ii) Economic importance of specimen R/Earthworm -it aerates the soil -It enriches/improves soil fertility. -its secretions neutralize the acid soil -used bait for fishing as food for some birds. (d) Type of fruit specimen S/unripe mango fruit - Drupe Specimen T/tomato fruit-Berry. (c)(i) Observable differences between specimens Sand T Specimen S/unripe mango fruit Specimen T/tomato fruit -green in colour red/yellow in colour one seeded many seeded - stony/hard endocarp fleshy/succulent/soft endocarp -fibrous mesocarp succulent mesocarp - seed large seed(s) small basal placentation axile placentation mesocarp and endocarp are fused mesocarp and endocarp are not fused Similarities between specimens S and T: -both have seeds -both are fruits -both have three layers/epicard/mesocarp/endocarp/pericarp/ fruit wall - coloured epicard/pericarp - both have placenta - both have thin epicard both have fleshy mesOcarp

(bi. Classification of Specimen F/Carrot Root tuber Specimen G / lrish potato Stem tuber ii. Reasons for classification Specimen F/Carrot -Swollen tap root - lateral roots present has a reduced stem (above the swollen tap root). Specimen G / irish potato swollen stem/ tuber -presence of bud(s)/eye -presence of scale leaves/leaf -presence of lenticel(s). (c) Class of specimens H and J Insecta (d(i). Observable differences between specimens Hand J H/adult mosquito J/adult cockroach - smaller in size big/large in size -a pair of wings two pairs of wings -absence of hard hind wing presence of hard hind wing/elytra -shorter antennae longer antennae -proboscis mandible absence of maxillary palp/maxilla presence of maxillary palp/maxilla - body is cylindrical body is dorso-ventraly flattened -thin legs thick large legs -absence of spines on legs presence of spines on legs ii. Similarities between specimens H adult mosquito and J/ adult cockroach: -presence of a pair of compound eyes -body is divided into three divisions/head, thorax and abdomen - three pairs of /six (walking) legs - presence of jointed appendages -presence of a pair of membraneous wings -presence of a pair of antennae -both have exoskeleton made of chitin -segmented body (e) Feeding habit of Specimen H / adult mosquito -piercing and sucking Specimen J / adult cockroach Biting and chewing. (ii) Observable features used for feeding in specimen J adult /cockroach Mandible; maxillae; labium; labrum

(a)(i) Phylum of specimens C / Butterfly and E / Grasshopper - Arthropoda (ii) Reasons : Metameric segmentation / segmented bodies, jointed appendages, presence of chitinoud exoskeleton made of chittin, bilateral symmetry (b) Differences: C / Butterfly D / Caterpillar wings are present wings are absent proboscis present mandibles present - proleg absent proleg present - legs are longer legs are shorter - claspers are absent claspers are present - has one pair of compound eyes has simple eyes - has antennae absence of antenna - Osmeterium absent - Osmeterium absent (ii) C and E C(Butterfly) - E (Grasshopper) -presence of proboscis presence of mandibles clubbed/rounded/knobbed antennae not clubbed/rounded/knobbed antennae/tapering antennae -wing is membraneous/soft harder/less membraneous wings surface of wing is powdery/have Scales/eye spots surface of wing is not powdery absence of scales/eye spots -wings are pigmented/colourful wings have uniform colour green/brown hind limbs/legs smaller/shorter/less muscular hind limbs/legs/larger and elongated/ more muscular - abdomen is hairy abdomen is not hairy/smooth (c) Relationship between specimens C/Butterfly and D/caterpillar: (i) C/Butterfly is the adult/imago of D/caterpillar: (ii) D/Caterpillar is the larva/larva stage of C/Butterfly. (d) (i) Habitat of specimen D/Caterpillar: Garden/citrus leaves/vegetables/leaves/fruits/green plant. (ii) Ways in which Specimen D/Caterpillar is adapted to its habitat: (i) Mandibles; for chewing: (ii) It has three pairs of true legs with claws; for locomotion: (iii) It has claspers; for attachment to vegetation/twig (IV) Presence of four pairs of proleg/false legs; for climbing: (V) Its coloured pattern; enables it to blend with its environment/camouflage/escape predators: (VI) It has spiracles: for gaseous exchange; (VI) It has Simple eyes; for vision; (Vii) Has osmeterium; as defense mechanism/which emits foul smell to scare away predators. (e) Diagram/drawing of dorsal view of specimen C/Butterfly

Number of students that plays only two games = 4 + 8 + 3 = 15

(2 x 4) + (3 x 4) + (4 x y) = 48 8 + 12 + 4y = 48 4y = 48 - 20 \(\frac{4y}{4}\) = \(\frac{28}{4}\) y = 7

The concept of centrifugal force can be applied in rotating devices, such as centrifuges, centrifugal pumps, centrifugal governors, and centrifugal clutches, and in centrifugal railways, planetary orbits and banked curves, when they are analyzed in a rotating coordinate system.

Properties of p type semiconductor This type of semiconductors form due to the doping trivalent atoms in a pure semiconductor crystal. The majority carriers in p-type semiconductors are holes which have positive charges. Minority carriers of this type semiconductors are free electrons.

The reactivity of halogens decreases as you move down Group 7. Halogens become less reactive as you move down the group as the atomic radius of the element increases which means that the distance between the outer shell of electrons and the nucleus increases.

\(\int\) \(\frac{2x^3 + 2x}{x}\) = \(\int\) \(\frac{2x^3}{x}\) + \(\frac{2x}{x}\) = \(\int\) (2x2 + 2) dx \(\frac{2x^2+1}{2 + 1}\) + 2x + k = \(\frac{2x^3}{3}\)+ 2x + k

\(\frac{4 + y + 8 + 10}{4}\) = 7 22 + y = 4 x 7 22 + y = 28 y = 28 - 22 = 6

Y = ( \(\frac{1}{3}\)X + 6)\(^2\) \(\frac{dy}{dx}\) = 2( \(\frac{1}{3}\)X + 6) \(\frac{1}{3}\) = \(\frac{2}{3}\) ( \(\frac{1}{3}\)X + 6)

80 - x + x + 60 - x + 20 = 150 160 - x = 150 x = 160 - 150 = 10

T2 = \(\frac{8}{9}\), T6 = 4\(\frac{1}{2}\) ar = \(\frac{8}{9}\) ar5 = \(\frac{9}{2}\) \(\frac{ar}{ar^5}\) = \(\frac{8}{9}\) x \(\frac{2}{9}\) \(\frac{1}{r^4}\) = \(\frac{16}{81}\) r = \(\sqrt[4]{\frac{18}{16}}\) = \(\frac{3}{2}\)