Figure;2. 22: Ascaris  
d.Phylum Annelida  
Members of this phylum are known as ringed or segmented worms. This is  
a large phylum comprising of lugworms, earthworms, and leeches. The  
species are adapted to various habitats; some members are aquatic, living  
in marine and fresh water, and others live in moist terrestrial environments  
Characteristics of Annelids  
❖ They are segmented worms  
❖ They have cylindrical body made of series of similar segments like  
rings.  
❖ They use nephridia for excretion and osmoregulation  
❖ Some are free-living and some are parasites  
❖ They possess bristles called chaetae for locomotion  
❖ They have bilateral symmetry  
Classes of Phylum Annelida  
(a) Class Oligochaeta  
(b) Class Poligochaeta  
(c) Class Hirudinea  
a) Class Oligochaeta  
General and distinctive features of class Oligochaeta  
❖ Have fewer chaetae (bristles)  
❖ They live in both fresh water or damp earth  
❖ They are hermaphrodites (have both sexes male and female  
parts)  
❖ Have clitellum for secretion of mucus  
Figure;2.24: Tilapia Fish  
Adaptation of tilapia fish to its mode of life  
❖ They have swim bladder for buoyancy maintenance  
❖ They have gill for respiration and are protected by operculum from  
mechanical damage  
❖ They have fin for locomotion  
❖ Has a streamlined shape to overcome water resistance during  
swimming  
❖ Its body surface is covered by cycloid scales, which point  
backwards in order to reduce resistance during swimming.  
❖ The fish has a lateral line that runs along the side of its body. The  
lateral line is a series of sensory organs called neuromasts that  
helps the fish to sense vibrations and water pressure for navigating  
and locating prey  
Economic importance of Tilapia fish  
❖ Used in biological studies.  
❖ Used as the source of food to human being.  
❖ Source of income.  
Class Reptilia  
The word reptilian is a Latin word which means ‘crawl’  
Some reptiles have limbs (e.g. lizards) while others are limbless (e.g.  
snakes)  
The reptiles occupy different habitats. Some are aquatic (e.g. Turtles)  
while others are terrestrial (e.g. Lizards). Example of reptiles are Tortoise,  
Turtles, Lizards, Snakes, Chameleons, crocodiles.  
Characteristics of Reptiles  
❖ Have dry skin covered with horny scales  
❖ They are poikilothermic animals (cold blooded animals)  
❖ They use lungs for gaseous exchange  
❖ Their eggs are fertilized internally and laid on land. A membrane  
known as amnion covers their eggs.  
❖ With exception of crocodiles, they have heart which is divided into  
two atria (singular atrium) and two partially divided ventricles. In  
crocodiles the heart has four chambers.  
❖ Some reptiles have shells e.g. Tortoise and turtles  
❖ The limbs of reptiles arise from the lateral side of the body  
Figure;2.25: Lizard  
Adaptation of lizard to its mode of life  
❖ Their dry skin is covered with horny scales to prevent dessication  
❖ Produce uric acid as waste which require less amount of water  
❖ Have nostrils for smell  
❖ They protruding eyes for wider field of view.  
Economic importance of lizard  
❖ Used in biological studies.  
❖ Source of food to some organisms  
Class Mammalia  
The class Mammalia consists of all animals with mammary glands. It is an  
extremely diverse and very advanced group in the kingdom Animalia.  
Members of the class Mammalia include: human, mouse, rabbit, cow, lion,  
bat, whale, and donkey.  
Characteristics of Mammals  
❖ Are homoeothermic (warm blooded)  
❖ Viviparous, give birth to young, not eggs (except platypus and  
echdina)  
❖ Have mammary glands  
❖ Have external ear pinnae, (singular pinna) for collecting sound  
waves.  
❖ Have heterodont teeth-varied teeth for different functions.  
❖ Have hairs or fur that covers the body for insulation  
❖ Have sweat glands, for cooling the body  
❖ Have diaphragm a muscular sheet separating the heart and the  
lungs from other organs.  
❖ Have red blood cells (erythrocytes) that lack nuclei but having  
hemoglobin for transportation of oxygen from the lungs to the  
respiring cells.  
❖ Possess pentadactyl limbs, limbs with five digits (phalanges) e.g.  
man, chimpanzee  
❖ Their heart has four chambers  
❖ They have highly developed brains.  
Figure; 2.26: Rat  
Economic importance of rat  
❖ Used for biological studies  
❖ Reservoir of human disease e.g bubonic plague  
❖ Consumers of grains that are basic food stuff to human being  
❖ Produce fur that are useful to man  
Adaptation of rat to its mode of life  
❖ They have heterodont dentition for various purpose  
❖ They have fur for insulation  
❖ Has well developed blood circulatory system  
❖ They have internal fertilization hence increase chances of survival  
Class Amphibia  
This class includes amphibians such as frogs, toads, caecilians as well as  
salamanders. Amphibians are tetrapod with the exception of caecilians,  
which are limbless  
Characteristics of Amphibians  
❖ They dwell both in water and on land, as they depend on water for  
reproduction, hence the name amphibian, which means double life.  
❖ Amphibians’ offspring begin their life cycle under water and  
breath by means of gills. As they grow to adulthood they move to  
terrestrial and breathe by means of either skin or lungs.  
❖ They have soft moist skin without scale, used for gaseous  
exchange to supplement lungs and buccal cavity.  
❖ Amphibian eggs have a jelly structure, which is prone to  
dehydration when exposed to air.  
❖ Amphibian’s fertilization takes place outside the female body (with  
the exception of some caecilians and some toads including the  
Kihansi spray toad which give birth to live young). They have two  
pairs of pentadactyl limbs for locomotion. The forelimbs have less  
musculature, while the hind limbs are webbed and long with  
powerful muscles for jumping.  
❖ They have long and protruding eyes for viewing preys widely and  
for avoiding enemies.  
❖ They have sticky tongue, which helps them in capturing prey.  
❖ They undergo metamorphosis for development from larval to adult  
stage in their life cycle.  
Figure; 2.27: Toad  
Adaptation of frog to its mode of life  
❖ Has long and muscular hind limbs for jumping  
❖ Has webbed feet for swimming  
❖ Has a long, sticky tongue for catching prey  
❖ Has lungs for gaseous exchange on land and skin on water  
Digestive system of a frog  
The alimentary canal of a frog consists of the mouth, buccal cavity,  
pharynx, oesophagus, duodenum, ileum, and the rectum, which open into  
the cloaca at the anus.  
❖ The mouth is wide for ingestion of large pieces of food material.  
❖ These tubes are used for balancing pressure in the inner ear while  
the frog is swimming. Ventrally in the midline there is a narrow  
longitudinal slit (glottis) which leads into the larynx.  
❖ They have a short oesophagus that bears longitudinal folds, which  
close to prevent entry of air into the stomach and allow dilation  
during swallowing of food. Buccal cavity, pharynx and oesophagus  
have cilia, which constantly drive the mucus backward through the  
pancreas. The pancreas lies and later discharge into the duodenum.  
In between the stomach and the duodenum.  
❖ The secretions are discharged into the bile spherical red structure  
called spleen, which duct, which become hepato-pancreatic duct has  
no digestive role  
Oesophagus  
Liver  
Gall bladder  
Duodenum  
Stomach  
Pancreas  
Ileum  
Rectum  
Cloaca  
Figure: digestive system of frog  
Class Aves  
The class Aves includes all birds. It is an extremely distinctive and  
successful class. Aves are bipedal feathered and warm-blooded  
(homoeothermous) animals, as they are able to maintain a constant body  
temperature.  
General Characteristics  
❖ Their mouth is modified into horny beaks  
❖ They have hollow bones filled with air  
❖ They have scaly legs  
❖ Body covered with feathers  
❖ Fertilization is internal  
❖ Use lungs for gaseous exchange  
❖ They have amniotic eggs  
❖ Fore limbs are modified into wings  
❖ Their heart has four chambered hearts  
Figure; 2.28: Pigeon  
Adaptation of Birds to its mode of life  
❖ Their body is covered with feathers for insulation and flight  
❖ They have wing for flight  
❖ They have streamed body to reduce air resistance  
❖ They have simple eyes for vision  
Economic importance of animals (kingdom Animalia)  
❖ Used for biological studies  
❖ Used as the source of food e.g cow, goat etc  
❖ Used for biological control  
❖ Used for security e.g. dogs  
❖ Used as the source of income  
❖ Some animals used for transport for example camels, donkeys  
❖ Provide manure for example cow dung  
Types of Feathers  
✓
✓
✓
Flight Feathers. Flight feathers are found in two places on birds:  
the wings and tail, They are used for flying  
Contour Feathers. Contour feathers give shape and color to the  
bird. ...  
Down Feathers. Down feathers have little or no shaft, they are  
used for insulation  
worked example  
2. You are provided with specimens D, E and F. Study them carefully and  
answer the questions that follow.  
a) (i) What is the common name for each of the specimens D, E and F?  
(ii) Why is it important to the scientists to classify specimens D, E and F  
to their lowest taxonomic groups? Give two reasons.  
b) Classify each of the specimens D, E and F to the phylum/Division level.  
c) Why are specimens D and F placed to the Phylum/Division you named in  
(b)? Give two reasons for each specimen.  
d) What do the processing industries benefit from using the plants in which  
specimen E was taken? Give three benefits.  
e)  
(i) Draw a well labeled diagram of the specimen F.  
(ii) State the habitat of the specimen F.  
(iii) What are the two advantages of specimen F to the farmer?  
ANSWERS  
2(a)(i)  
Specimen  
Common name  
Bread mould  
Pine branch (pine leaf)  
Earthworm  
D
E
F
(i) Importance of classification  
❖ It makes easy to classify all known organisms and predict the  
placement of the yet to be discovered based on already known  
features.  
❖ Classification simplifies communication among taxonomists  
worldwide.  
❖ It helps to show evolutionary relationship between organisms.  
❖ Organisms grouped in the same taxon, such as at genus level,  
normally have many common features.  
❖ It paves a way towards understanding other disciplines, such as  
ecology, medicine and pharmacy  
(b)  
Specimen Kingdom  
Phylum  
Zygomycota  
_
Division  
-
Coniferophyta  
-
D
E
F
Fungi  
Plantae  
Animalia  
Annelida  
(c) Features of Zygomycota (specimen D)  
❖ They have aseptate hyphae which lack cross walls between  
adjacent cells. They are therefore coenocytic in structure.  
❖ Their cytoplasm is continuous and multinucleate.  
❖ They undergo sexual reproduction involving two gametangia to  
produce a resting spore known as zygospore  
Features of Annelida (specimen F)  
❖ They are segmented worms  
❖ They have cylindrical body made of series of similar segments like  
rings.  
❖ They use nephridia for excretion and osmoregulation  
❖ Some are free-living and some are parasites  
❖ They possess bristles called chaetae for locomotion  
❖ They have bilateral symmetry  
(d) Advantages of division coniferophyte  
❖ Provide soft woods for construction  
❖ Used in making drugs  
❖ Prevent soil erosion  
❖ Production of turpentine and resin from pines  
❖ They are ornamental plants  
(e) (i)  
Fig: diagram of specimen F  
(ii)  
The specimen F is found in moist soil  
(iv) State three distinctive features that made you and other scientist to  
agree specimen C and F must dwell in the class(s) you mentioned in (b) iii  
and not otherwise  
(c) (i) In which ways are specimen C and F of advantage to man  
(ii) Draw a diagram of specimen F and label the parts which are  
involved in sensitivity and locomotion.  
ANSWERS  
2.(a)( i).  
Specimen  
Common name  
Maize seedling  
Bread mould  
Grasshopper  
C
D
F
(ii)  
Specimen  
Kingdom  
Plantae  
Fungi  
C
D
F
Animalia  
(b) (i)  
Specimen  
Habitat  
C
D
F
Found terrestrial habitat  
Found on decayed bread  
Found on grassland  
(ii) Adaptation of bread mould to its habitat  
❖ Have rhizoids for absorption of nutrients  
(iii)  
Specimen  
Class  
C
F
Monocotyledonae  
Insecta  
(iv) Distinctive Features of Monocotyledonous plants  
❖ Vascular bundles are scattered in stem  
❖ They have no vascular cambium except in palms  
❖ They have no tap root  
❖ They have one cotyledon  
❖ They undergo hypogeal germination  
❖ Usually wind-pollinated  
Distinctive Features of Class Insecta  
❖ The body is clearly divided into three regions i.e. head,  
thorax and abdomen  
❖ They have one pair of antennae for sensitivity  
❖ They have three pairs of jointed walking legs  
❖ Some have two pairs of wings (inner and outer wings)  
e.g., grasshopper, beetle  
(c)(i) Advantages of maize seedling  
❖ Source of food to human being and other animals  
❖ Used for biological studies  
❖ Increase soil fertility  
Advantages of maize seedling  
❖ Source of food to human being  
❖ Source of oxygen  
❖ Used in biological studies  
(i)  
Refer from notes  
Worked example 2  
2. You are provided with specimens L, M, N and P.  
a) (i). Identify each specimen L, M,and N by using their common  
names.  
(ii).Observe the specimens M, N and P carefully; they classify  
each specimen to its respective group from Kingdom to class level.  
b) (i) State four observable features which prompted you and other  
scientists to place specimen L in the class Mammalia.  
(ii) Give the reason to why specimen N was formally placed in the  
Phylum you mentioned in (a) (iii)?  
c) Draw a diagram of specimen P and label the structures involved in  
locomotion only.  
d) With an example, explain why most of the members belonging to  
the Kingdom in which specimen L belongs are of advantages to  
other living organisms.  
ANSWERS  
(c). Required to draw a diagram of specimen P and label the structures  
involved in locomotion only (Refer from notes)  
(d). Most members belong to the kingdom in which L belongs are  
advantages to other living organisms  
Reasons: -  
❖ Source of food - some are eaten by other organism example fish,  
locust, rabbit is eaten by man.  
❖ Some are host of parasites – example cow, goat, dog are hosts of  
lice, tick and fleas.  
❖ Source of fibers – example spider that produce silk for making  
clothes used by man.  
❖ Milk and meat production – example cow and goats that produce  
milk for man.  
❖ Pollination – some organisms transfer pollen grains and fertilize  
crops and increase crop production, example bees and butterflies.  
❖ Medical research - are conducted by researchers to identify the  
potentiality of new medicines through small organisms. Examples  
testing antibiotics done by man on rats and rabbits.  
Worked example 3  
2.You have been provided with specimens R,S, T and U  
a) Study specimens R, S, T and U carefully, then: -  
(i) Identify specimens R, S, T and U using their common names.  
(ii) Classify specimen S and U to class level.  
b) (i). Draw a well labeled diagram of specimen R  
(ii). State six advantages of specimen R  
c) Observe the structures of specimen T.  
(i)Name the Kingdom and Division in which the specimen T  
belongs.  
(ii) Explain five general characteristics of the Division in which  
specimen T belongs.  
ANSWERS  
2.(a) i.To identify each specimen by using their common names  
Specimen  
Common name  
worked example 4  
2.You have been provided with specimens R,S and T  
(a)Observe the specimens then:  
(i) Identify the specimens R,S and T by their common name.  
(ii) Classify specimen S and T to phylum level  
(iii) Name the class and state two distinctive features for each class of  
specimens R, S and T  
(b) Study the specimens R, S and T carefully and then answer the  
following questions:  
(ii) State the habitat of specimen R and S.  
(iii)State the adaptation features which indicates how specimen S is  
adapted to its habitat.  
(iv) In what ways are specimen S and T considered to be useful and  
harmful to human being and his environment.  
ANSWERS  
2.(a)(i)  
Specimen  
Common name  
Crab  
Grasshopper  
Rat  
R
S
T
(ii)  
Specimen  
Kingdom  
Phylum  
S
T
Animalia  
Animalia  
Arthropoda  
Chordata  
(iii) Specimen R is placed class Crustacea  
Distinctive features of class Crustacea  
❖ Have one pair of compound eyes raised in stalk  
❖ Some have two pairs of antennae e.g. lobster, prawns,  
crabs, examples of crustaceans are crabs, prawns, lobsters.  
❖ Their gaseous exchange is by means of gills or through  
body membrane  
Specimen S is placed in Class Insecta  
Distinctive features of class Insecta  
❖ They have one pair of antennae for sensitivity  
❖ They have three pairs of jointed walking legs  
❖ Some have two pairs of wings (inner and outer wings) e.g.  
grasshopper, beetle  
❖ Some have one pair of wings e.g. housefly, bees  
❖ They  
have  
well  
developed  
compound  
eyes  
(with  
ommatidia)  
Specimen R is placed in Class Mammalia  
Distinctive features of class Mammalia  
❖ Have heterodont teeth-varied teeth for different functions.  
❖ Have hairs or fur that covers the body for insulation  
❖ Have sweat glands, for cooling the body  
❖ Have diaphragm a muscular sheet separating the heart and  
the lungs from other organs.  
❖ Have red blood cells (erythrocytes) that lack nuclei but  
having hemoglobin for transportation of oxygen from the  
lungs to the respiring cells.  
(b) (i)Specimen R is found in Water bodies e.g. rivers, seas  
Specimen S is found in grassland and trees  
(ii) Adaptation of Grasshopper to its habitat (specimen S)  
❖ It has one pair antenna for sensitivity  
❖ It has exoskeleton for mechanical protection and support  
❖ It has two pairs of wings for movement  
❖ It has three pairs of jointed legs for locomotion  
(iii) Advantages of grasshopper (specimen S)  
❖ Source of food to human being  
❖ Used for biological studies  
Disadvantage of Grasshopper (specimen S)  
❖ Destroy crops  
Advantages of Rat (specimen T)  
❖ Used for biological studies  
❖ Produce fur that are useful to man  
Disadvantage of Rat (specimen T)  
❖ Reservoir of human disease e.g bubonic plague  
❖ Consumers of grains that are basic food stuff to human.