1. a) i) What is meant by the term binomial nomenclature?

scientific system of naming organisms using the generic(genus) and specific (species)

ii) State briefly the general principles of classification of living organisms
  • scientific names must be in Latin or should be Latinised
  • family names are formed by adding the suffix “idea” to the stem of the genus e.g the genus Rana becomes Ranaidea
  • generic names should be a single unique name

b) State the main characteristics of the five kingdoms of organisms

i. Monera

e.g. bacteria
  • unicellular (single-celled)
  • prokaryotic (genetic material not surrounded by a membrane)
  • cell Wall without cellulose
  • lack most organelles
  • small in size (microscopic)
ii. Protista(protoctista)
  • single-celled(unicellular)
  • eukaryotic (most cell organelles present)
  • when cell Walls are present have no cellulose
  • e.g. protozoa and algae
  • usually microscopic

iii. Fungi
  • have hyphae (which form mycelia)
  • absence of chlorophyll
  • have rhizoids (lack roots, leaves, stem)
  • have spore forming structures (sporangia)
  • e.g. mucor, rhizopus
iv. Plantae
  • most are green/contain chlorophyll
  • autotrophic/feed by photosynthesis
  • cells have cellulose cell walls
  • respond slowly to stimuli (tropism)
  • lack locomotion (are stationary)
  • indefinite growth (at meristems)
  • lack specialized excretory structures
v. Animalia

  • cells do not have cell walls
  • most carry out locomotion
  • heterotrophic
  • fast response to stimuli (tactic)
  • have specialized excretory structures
c) Describe the economic importance of

i. Fungi
  • some cause decay to our food
  • some cause diseases in humans and animals e. g. ringworms
  • may be used as food e. g. mushrooms, yeast
  • some are used in the production of antibiotics e. g. penicillin, chloromycetin, streptomycin
  • yeast is used in the brewing industry, and baking and source of vitamin B
  • many cause diseases to our crops e. g. late blight
  • important in recycling nutrients in the soil since they cause the decay of organic matter
  • mycorrhizal association in forest development may help in Water intake/absorption
  • help in nitrogen fixation

ii. Bacteria

  • are useful in the manufacture of antibiotics
  • silage formation,
  • fermentation of cheese, butter, milk yoghurt
  • curing of tea, tobacco and retting flax
  • formation of vitamin B12 and K
  • enzymes such as amylase and invertase
  • hormones such as insulin '
  • vinegar, acetic acid, lactic acid, citric acid
  • in septic tanks and modern sewage Works make use of bacteria
  • biogas production
  • saprophytic bacteria are used in compost decomposition or cause decay
  • symbiotic bacteria are used in compost decomposition or cause decay
  • symbiotic bacteria in herbivores/ruminants help in digestion
  • some diseases in animals/humans and plants are caused by bacteria
  • many bacteria cause‘ food spoilage/decay
  • nitrifying and nitrogen fixing bacteria increase soil fertility/make nitrates available
  • denitrifying bacteria reduce soil fertility/convert nitrates into nitrogen/reduce nitrates
d) State the main characteristics of the following division of kingdom plantae

i. Bryophyte

 e.g. mosses and liverworts
  •  presence of rhizoids
  •  lack of vascular tissues (lack phloem and xylem)
  •  body pans not differentiated into root, stem, leaves
  •  capsule or seta
  •  gametophyte generation dominant.
ii. Pteridophyta

e.g. ferns
  • has true roots, stems and leaves
  • fond with sori on under-surface
  • vascular tissues present
  • sporophyte generation is dominant
iii. Spermatophyte
  • photosynthetic
  • well-differentiated into roots, stems and leaves
  • well-developed vascular system
  • seed-bearing plants
e) Name sub-divisions of spermatophyte and state the characteristics of each class

i. Gymnospermae (cornifers)
  • naked seeds (exposed
  • are all woody trees
  • reproduce by means of cones
  • show xerophytic characteristics
  • xylem have tracheids but lack vessels
  • phloem lacks companion cells ~
  • single fertilization
  • pollen lands directly on ovules
ii. Angiospermae (flowering plants)

  • reproduce by flowers
  • seeds enclosed (in fruits)
  • flowers bisexual hence double fertilization
  • herbaceous
  • pollen grains land on the stigma of the pistil
  • xylem contains vessels
  • phloem contains companion cells
  • ovules contained in the ovary
iii. Name the classes and state characteristics of angiospermae

  • two seed leaves
  • network venation of leaves
  • regularly arranged vascular bundles
  • tap root system
  • broad leaves
  • secondary growth occurs
  • one seed leaf
  • parallel venation of leaves
  • irregularly arranged vascular bundles
  • fibrous root system
  • narrow leaves
  • sheath-like leaf stalk (petiole)
  • no secondary growth
iv)State the importance of plants
  • balancing carbon IV oxide and oxygen in the atmosphere during photosynthesis and respiration influence water cycle
  • reduce soil erosion by binding soil particles together
  • useful products e. g. food, medicine, timber, paper, and clothing
  • habitat ( e. g. forests and grassland) for animals which may also be tourist attractions that earn money from the sales of products
  • aesthetic value/beauty e. g. flowers, shade/shelter, live fences, windbreaks
  • Some are harmful e. g. poisons, weeds, injurious (stinging nettles, thorns), water hyacinth

f) i) Give the general characteristics of phylum arthropoda
  • jointed appendages
  • presence of exoskeleton
  • triploblastic and coelomate
  • segmented body
  • bilateral symmetry (similar halves)

ii. State the characteristics of the following classes of arthropoda


the millipedes
  • two pairs of legs per segment
  • many segments
  • terrestrial habitat
  • body cylindrical and long
  • herbivorous
  • one pair of antennae


the centipedes
  • one pair of legs per segment
  • many segments
  • terrestrial habitat
  • body long and ventrodorsal flattened
  • carnivorous
  • last pair of legs pointing backward with poison claws called maxillipedes
  • one pair of antennae

  • three body pans i.e. head thorax, abdomen
  • six legs/three pairs of legs
  • a pair of compound eyes
  • presence of wings
  • a pair of antennae


  • two body parts
  • segmented body
  • have pincers (modified legs) to catch prey
  • have hard exoskeleton
  • a pair of compound eyes
  • body divided into two parts( abdomen and cephalothorax)
  • simple eyes
  • eight legs (four pairs of legs)

iii) State the economic importance of insects

Beneficial effects
  • food supply
  • important in food chains
  • pollinators
  • biological control of pests and other organisms
  • aesthetic value
  • contribute to decomposition e. g. litter feeders like beetles

Harmful effects
  • pests
  • vectors
  • dirt and disease carriers
  • injurious e.g. stings and bites

g) i) State the general characteristics of chordate
  • notochord
  • dorsal slits (pharyngeal cleft during development)
  • bilateral symmetry
  • triploblastic (three layer body-ectoderm, mesoderm and endoderm)
  • clear cut head formation
  • multilayered epidermis
  • post-anal tail
  • closed circulatory system
  • segmented muscle blocks(myotomes)
  • single pair of gonads

ii)Give the characteristics of the following classes of chordate

  • presence of fins for locomotion
  • two-chambered heart *
  • presence of overlapping scales ~
  • presence of gills or operculum for gaseous exchange
  • presence of lateral line for protection
  • streamlined body
  • poikilothermic (body temperature varies with that of environment)
  • partially live in fresh Water and partially on land
  • poikilothermic
  • pentadactylous with two pairs of limbs
  • webbed feet for locomotion in water
  • body streamlined
  • heart is three chambered
  • moist skin for gaseous exchange

  • scales on body
  • poikilothermic
  • homodont teeth except tortoise and turtle
  • all have limbs except snakes
  • skin is dry
  • oviparous (lay eggs)
  • no pinna (external ear)
  • three-chambered heart 9crocodile has four chambers)
  • skin not glandular
  • no mammary glands

the birds
  • homoeothermic (constant body temperature)
  • four-chambered heart
  • streamlined body for locomotion in air
  • skin dry and covered by feathers
  • scales on legs
  • hollow bones
  • oviparous (lay eggs)
  • mouths modified into beaks
  • hair on the body
  • homoeothermic
  • viviparous (give birth to live young) eXcept a few
  • have mammary glands
  • glandular skin e.g. sweat glands, sebaceous glands
  • four chambered heart
  • pinna (external ear)
  • two pairs of pentadactyl limbs
  • presence of diaphragm
  • have salivary glands

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