PRACTICAL 2025
SPECIMEN A = PRAWN
IDENTIFY SPECIMEN A - Prawn
HABITAT – Rivers / Swamps
METHOD OF FEEDING – Filter feeder
FEEDING HABIT – Herbivorous and detritivorous
RESPIRATORY STRUCTURE - Gills
PHYLUM – Arthropoda
Reasons
1. Presence of chitinous exoskeleton
2. Metameric segmentation
3. Bilaterally symmetrical
CLASS = Crustacea
Reasons
1. Possess two pairs of antennae
2. Possess five pairs of walking legs on cephalothorax
3. Possess two body divisions, cephalothorax and abdomen
OBSERVABLE CHARACTERISTICS
• Stalked eyes
• Two pairs of antennae
• Two body divisions, cephalothorax and abdomen
ADAPTIVE FEATURES
1. Presence of carapace for protection against mechanical injury
2. Swimmerets for swimming
3. Chela have claws for defense
4. Stalked eyes for vision in all directions
ECONOMIC IMPORTANCE
• Source of food / Protein
• Source of income
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A drawing of the lateral view of specimen A
X1
SPECIMEN B – EARTHWORM
METHOD OF FEEDING – Detritivorous
REASON FOR METHOD OF FEEDING – Feeds on dead decaying organic matter such as dead leaves
HABITAT – Moist soil / Burrows in moist soil
PHYLUM – Annelida
Reasons
1. Metameric segmentation
2. Cylindrical body
3. Presence of chaetae on each body segment
4. Body tapered at both ends
CLASS – Oligochaeta
Reasons
1. Presence of clitellum
2. Possess few chaetae but no parapodia
3. No distinct head
4. No eyes
LOCOMOTORY STRUCTURE – Chaetae
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LOCOMOTORY METHOD – Peristaltic
REPRODUCTION – Sexual and hermaphroditic with cross fertilization and exhibit oviparity (lay eggs)
FUNCTION OF PARTS
• Clitellum for attachment during mating
• Chaetae for locomotion
RESPIRATORY STRUCTURE – Skin
EXCRETORY STRUCTURE – Nephridium
TYPE OF SKELETON – Hydrostatic skeleton
SUBSTANCE MAKING THE SKELETON – water / coelomic fluid
ADAPTIVE FEATURES OF EARTHWORM
1. Tapering anterior and posterior ends to push through burrows
2. Flexible body for burrowing through litter
3. Moist body for effective gaseous exchange
4. Clitellum for mating
5. Moist boy provide lubrication for easy movement
ADAPTIVE FEATURES FOR DEFENSE
• Dark dorsal surface blends with dark soil
• Moist mucus kills bacteria and fungi
ECONOMIC IMPORTANCE
1. Aerates the soil by burrowing
2. Loosens soil for easy passage of roots
3. Turns the soil and improve soil texture
4. Add faecal matter / humus to the soil
Drawing of the lateral view of specimen B
X1/2
3
DIFFERENCES BETWEEN SPECIMEN A (PRAWN) AND SPECIMEN B (EARTHWORM)
SPECIMEN A / PRAWN SPECIMEN B / EARTHWORM
• Posses jointed legs for locomotion • Has chaetae for locomotion
• Stalked eyes present • Eyes absent
• Cream or light brown in colour • Dark brown in colour
• External exoskeleton • Exoskeleton absent
• Antennae present • Antennae absent
• •
SPECIMEN C – QULL FEATHER
IMPORTANCE OF FEAHTERS TO BIRDS
• For courtship
• Provide warmth
• Camouflage
• For flight
ECONOMIC IMPORTANCE OF FEATHERS
1. Feathers are used for decoration
2. For making pillows
3. For religious purposes
Drawing of the dorsal view of specimen C
X½
4
LOCATION ON THE BODY – On the wings and tail
FUNCTIONS OF QULL FEATHER
1. Used for flight
2. The tail feathers are used for steering and braking
FEATURES OF ADAPTATION
• It is light and hollow to promote easy flight
• Interlocking barbs provide a large surface area for flying
• Interlocking barbs and barbules makes it air and waterproof
• Rachis strengthens the feather
FEATURES OF BIOLOGICAL IMPORTANCE
1. For flight
2. Adaptive colouration for camouflage and for courtship
3. Waterproof
4. It is flat and broad to protect against desiccation
CHEMICAL COMPOSITION OF FEATHERS – Keratin which is protein in nature
SPECIMEN D – CLAW OF A DOMESTIC FOWL
CHEMICAL COMPOSITION – Keratin
BIOLOGICAL IMPORTANCE OF CLAW TO BIRDS
1. Sharp claws for scratching/digging the soil to search for food
2. Claws provide easy grip when perching or roosting
3. Sharp and pointed claws for defense
4. Claws to assert dominance
SPECIMEN E – SPIDER
MODE OF NUTRITION – Holozoic
MODE OF FEEDING – Carnivorous / Reason – Presence of chelicerae for catching and capturing insects
RESPIRATORY STRUCTURE – Book lung
PHYLUM – Arthropoda
Reasons
1. Possess exoskeleton made of chitin
2. Possess jointed appendages
3. Bilaterally symmetrical body
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CLASS – Arachnida
Reasons
1. Possess two body divisions, prosoma and opisthosoma
2. Possess a pair of chelicerae on cephalothorax
3. Possess four pairs of walking legs
ADAPTIVE FEATURES FOR FEEDING
• Chelicerae or poison jaw for catching prey
• Silk spinning organs / spinnerets produce silk for catching prey
• Possess simple eyes to detect prey
ECONOMIC IMPORTANCE OF SPIDER
1. Biological control of insect pests
2. Some are poisonous by their bite
3. Food for some organisms
DIFFERENCES BETWEEN SPECIMEN A / PRAWN AND SPECIMEN E / SPIDER
SPECIMEN A / PRAWN SPECIMEN E / SPIDER
• Possess five pairs of jointed legs • Possess four pairs of jointed legs
• Swimmerets present • Swimmerets absent
• Antennae present • Antennae absent
• Chelicerae absent • Chelicerae present
• Possess stalked eyes • Eyes not on stalk
• Pedipalp absent • Pedipalp present
SIMILARITIES BETWEEN SPECIMEN A / PRAWN AND SPECIMEN E / SPIDER
• They both possess external exoskeleton made of chitin
• They both possess two body divisions
• They both have eyes
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Drawing of the dorsal view of specimen E
X20
SPECIMEN F – GIANT AFRICAN SNAIL
HABITAT – Forest floor / Under leaf litter/ garden farm
FEEDING HABIT – Herbivorous
METHOD OF FEEDING – Uses radula to rasp green vegetation
PHYLUM – Mollusca
Reasons
1. Presence of calcareous shell
2. Presence of head and muscular foot
CLASS – Gastropoda
Reasons
1. Possess single coiled shell
2. Possess eyes on tentacles on head
3. Possess radula
MODE OF LIFE
✓ They are active at night / nocturnal, buried in the soil during the day
✓ Can aestivate up to three years in times of drought
✓ Uses slimy muscular foot for locomotion
REPRODUCTION – Hermaphrodite but cross fertilization / Oviparous – lay shelled eggs
RESPIRATORY STRUCTURE – Lungs
ECONOMIC IMPORTANCE OF SNAIL
1. Source of food
2. Source of employment
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3. Agricultural pest
4. Shell used for decoration
FUNCTIONS OF THE SHELL
✓ Protection against mechanical injury
✓ Protection against desiccation
✓ Provides camouflage
✓ Protection during aestivation
Drawing of the ventral view of specimen F
X1
SPECIMEN G – MILLIPEDE
HABITAT – Leaf litter / Farm / Garden
PHYLUM – Arthropoda
Reasons
1. Possess chitinous exoskeleton
2. Possess metameric segmentation
3. Bilaterally symmetrical
CLASS – Diplopoda
1. Possess two pairs of legs per body segment
2. Distinct head
3. Possess a pair of antennae
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FEEDING HABIT – Detritivorous
ECONOMIC IMPORTANCE
1. Pest of crops and seedling
2. Improves soil fertility by burrowing/aerating soil
3. Break up litter to form humus to enrich the soil
Drawing of the lateral view of specimen G
X½
SPECIMEN H – CACTUS
HABITAT – Savanna / Desert / Arid regions
Reasons
• Presence of succulent stem
• Presence of thick waxy cuticle
• Presence of reduced leaves forming spines
DIVISION – Angiospermophyta / Magnoliophyta
Reasons
1. Seeds enclosed in a fruit
2. Produces flowers
REPRODUCTION IN CACTUS – Vegetative propagation
Reason – Presence of nodes and buds
MODE OF NUTRITION – Photosynthetic
CLASS – Dincotyledoneae
TYPE OF PLANT – Xerophyte
Reasons / ADAPTATIONS
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1. Thick and fleshy/ succulent stem to store water
2. Possess shallow widespread roots to quickly absorb rain water
3. Have a small surface area due to their cylindrical shape to reduce water loss
4. Leaves reduced into spines to reduce water loss by transpiration
5. Green stem contain chlorophyll for photosynthesis
Drawing of the lateral view of specimen H
X½
SPECIMEN J – STEM OF CASSAVA PLANT
DIVISION – Angiospermophyta
Reasons
1. Seeds enclosed in a fruit
2. Produces flowers
CLASS – Dicotyledoneae
Reasons
• Leaves net venation
• Leaves have leaf stalk
• Possess tap root system
TYPE OF REPRODUCTION – Vegetative propagation
Reasons
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• Presence of buds and nodes
FEATURES OF BIOLOGICAL IMPORTANCE / OBSERVERBLE FEATURES
1. Presence of nodes
2. Possess lateral buds
3. Leaf scar
4. Lenticel
5. Adventitious roots
X½
SPECIMEN K – AGERATUM LEAF
DIVISION – Angiospermophyta
Reasons
1. Seeds enclosed in a fruit
2. Produces flowers
CLASS – Dicotyledoneae
Reasons
1. Possess leaf stalk
2. Leaf has net venation
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TYPE OF LEAF MARGIN – Toothed / Serrated
TYPE OF LEAF – Simple leaf
Reason – Has a single leaf blade
Drawing of the dorsal view of specimen K
Apex
Leaf margin
Midrib
Lamina
Petiole
Leaf base
X2
SPECIMEN L – LEAF OF FLAMBOYANT PLANT
DIVISION – Angiospermophyta
CLASS – Dicotyledoneae
Reasons
• Leaf possess net venation
• Leaf possess a leaf stalk
TYPE OF LEAF – Bipinnately compound leaf
Reason – The main leaf blade is divided into leaflets with the leaflets subdivided into smaller leaflets
LEAF MARGIN – Smooth leaf margin
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LEAF SHAPE – Oblong shaped
SPECIMEN M – LEAF OF COMMELINA PLANT
DIVISION – Angiospermophyta
CLASS – Monocotyledoneae
Reasons
1. Possess parallel leaf venation
2. Leaf possess a leaf sheath
LEAF SHAPE – Lanceolate / Egg-shaped
LEAF MARGIN – Smooth / Entire
SPECIMEN N – INNOMINATE BONE OF A SMALL MAMMAL
IDENTIFY SPECIMEN N - Pelvic girdle of a small mammal
Reasons
1. Presence of acetabulum
2. Presence of obturator foramen
LOCATION IN ORGANISM – Hip
PART OF SKELETON – Appendicular skeleton
CLASSIFY BONE – Pelvic girdle / Appendicular skeleton
BONES ARTICULATED WITH – Femur and sacrum
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ARTICULATING SURFACES – Inner surface articulate of ilium articulates with sacrum
• Acetabulum articulate with the head of femur
TYPE OF JOINT WITH FEMUR – Ball and socket joint
TYPE OF MOVEMENT AT THE JOINT – Allow movement in all planes
TYPE OF JOINT WITH SACRUM – Fixed joint / Immovable joint
ADAPTATION / FUNCITONS OF PELVIC GIRDLE
1. Obturator foramen for passage of blood vessels
2. Protect abdominal organs such as urinary bladder and reproductive organs in females
3. Support and distribute the weight of the hind limbs
4. Acetabulum provide surface for articulation with the head of femur
5. Ilium provides surfaces for muscle attachment
DIFFERENCE BETWEEN PELVIC GIRDLE IN MALE AND FEMALE MAMMAL
• Larger in females than in males
SIGNIFICANCE / IMPORTANCE
1. Carries and protect pregnant foetus
2. Allow for the passage of head of baby during birth
Drawing of the ventral view of specimen N
X1
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