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INVERTEBRATES1 Phylum Porifera2 Phylum Coelenterata/Cnidaria3 Phylum Platyhelminthes4 Phylum Nematoda5 Phylum Annelida6 Phylum Mollusca7 Phylum Arthropoda

(a) Class Crustacea(b) Class Chilopoda(c) Class Arachnida(d) Class Merostomata(e) Class Insecta(f) Class Diplopoda

8 Phylum Enchinodermata(A) QUESTIONS & ANSWERS

VERTEBRATESPhylum Chordata

9 Class Chondrichthyes (cartilaginous fishes)10 Class Osteichthyes (bony fishes)11 Class Amphibia12 Class Reptilia13 Class Aves14 Class Mammalia

(i) Order Insectivora(ii) Order Chiroptera(iii) Order Dermoptera(iv) Order Carnivora(v) Order Rodentia(vi) Order Pholidota(vii) Order Lagomorpha(viii)Order Primates(ix) Order Artiodactyls

(B) QUESTIONS & ANSWERS

PHYLUM PORIFERA

Example : Leucosolenia (Sponge)

Unique characteristics :

Multicellular animal Simple body structure Asymmetry body The cell are arranged loosely without real tissue Body consists of two layers of cells-pinacoderm on the external surface and choanoderm on

the internal Choanoderm consists of flagellated collar cells Folded body walls and numerous pores The body walls are supported by calcium skeleton, silica spicules/ sponging fibres Body cavity is called spongocoel Osculum, a large body opening at one end Undifferentiated nervous system

PHYLUM COELENTRATA / CNIDARIA

Example : Obelia sp. (Hydra)

Unique characteristics :

Lower stage multicellular animal Radial symmetry Diploblastic (two germ layers) Nematocyst Nervous system consists of network of nerve cells Tentacles around the manubrium (mouth) Alternation of generation between polyp and medusa stage

PHYLUM PLATYHELMINTHES

Example : Dugesia sp. (Planarian)

Unique characteristics :

Flatworm Most member are parasitic except class Turbellaria Parasitic representative lacks both respiratory and circulatory systems Simple digestive system or none at all Excretory system is called the ‘flame’ cell The mouth on the ventral side The eyes on the dorsal side

PHYLUM NEMATODA

Example : Ascaris lumbricoides (roundworm)

Unique characteristics :

Non-segmented Pseudocoelomates Complete digestive tract The muscles of nematode are all longitudinal Body covered with tough cuticles

PHYLUM ANNELIDA

Example : Pheretima sp. (earthworm)

Unique characteristics :

Segmented body The segments are normally separated by compartments which are called septum The chaetae on the body are used to help in locomotion

PHYLUM MOLLUSCA

Example : Achantina fulica (garden snail)

Unique characteristics :

Has a large muscular body Visceral organ present Has radula A mantle whose function is to secrete shell

PHYLUM ANTHROPODA

Unique characteristics :

Segmented animals Mostly terrestrial Exoskeleton from chitin Paired jointed appendages Tripoblastic and bilateral symmetry Respiratory system consists of the tracheal system which opens through spiracles Aquatic Anthropods respire through external gills The sensory and nervous systems are concentrated at the head region

Example :

a) Class Crustacea - crab

b) Class Chilopoda - centipede

c) Class Arachnida - spider

d) Class Merostoma - horseshoe crab

e) Class Insecta - grasshopper

f) Class Diplopoda - millipede

PHYLUM ECHINODERMATA

Example: Asterias sp. (star fish)

Unique characteristics:

Triploblastic Locomotion using tube feet Skeleton from calcium carbonate plates Simple digestive system Part of the coelom is modified to become water vascular system

(A) QUESTIONS & ANSWERS1. (a) What is the advantage of the folded body walls in sponges?

The advantage of folded body walls in sponges is enhanced efficiency for the sponges' ability to gather food and oxygen, and to rid itself of waste. This configuration maximizes the sponges' pumping capacity while, at the same time, slowing the flow of water past each cell.

(b) What is the function of spicule other than support?Spicule’s another function is to protect sponges from predators and environmental threat.

(c) Which characteristic that make spongia important/essential for domestic use?It has arrangement of chamber as well as being flexible rather than crystalline spicules. Holes inside the fabric retain water via surface tension.

2. Phylum Coelenterata shows polymorphism. Name the two types of polymorphism.

Polypoid and medusoid.

3. List some adaptations possessed by Platyhelminthes as endoparasites.i.Covered by protective tegument which is specialized body covering resistant to digestive

juice.ii.Produce large number of eggs. iii.Anterior end with hooks or suckers for attachment to the host. iv.Well developed reproductive system helps to ensure successful transmission to the host.

4. (a) What is meant by metameric segmentation?Division of animal body (except the head region) into a number of compartments (segments) each contain the same organs.

(b) State the advantages of metameric segmentation in Annelids.Increases the efficiency of body movement by allowing the effect of muscle contraction to be extremely localised. Individual segments are specialised for different task.

(c) What is the function of clitellum?

Clitellum functions to hold the fertilized egg and then make a cocoon that hold the zygote of worm.

5. What is the function of radula? A radula is a rasp tongue that snails used for feeding or food provision.

6. Compare the members of the classes under phylum Arthropoda based on the following characteristics:

(a) parts of the body (b) number of appendages (c) the number of antennae (d) type of respiratory organ

Class Part of the body

Number of appendage

s

Number of antennae

Type of respiratory organ

Class Crustacea

Head, thorax and abdomen

4 (2 pairs) Book gills

Class Chilopoda

Head and trunk 2 (1 pair) Tracheal tubes

Class Arachnida

Cephalothorax and abdomen

None Book lungs

Class Merostomata

Head, abdomen and tail

None Book gills

Class Insecta Head, thorax and abdomen

2 (1 pair) Tracheal tubes

Class Diplopoda

Head and trunk 2 (1 pair) Tracheal tubes

7. What is the function of the vascular water system in a star fish?Vascular water system in a star fish functions in locomotion, feeding and gas exchange.

CLASS CHONDRICHTHYES

Example : Shark / Ray Fish

Unique characteristics :

Flexible endoskeletons made of cartilage rather than bone Clasper – slender, grooved section present in mature male Caudal fin is heterocercal Sharp teeth evolved from the jagged scales that cover the abrasive skin Sensory pore in front of the mouth Non- movable rudimentary eye lids: a pair of spiracles Gill slits Cloaca and lateral line system

CLASS OSTEICHTHYES

Example : selar

Unique characteristics :

Bony skeleton with many vertebrae Operculum – a lateral bony flap Caudal fin is homocercal Teeth in jaws Unpaired median fins Paired pelvis and pectoral fins

CLASS AMPHIBIA

Example : Bufo sp. / Rana sp.

Unique characteristics :

Non-scaly Soft and moist glandular skin which also function as a respiratory surface Tetrapods, thin webbed feet for paddling and crawling Double nostrils which open up into the mouth cavity and lead to the lungs Wide mouth with small teeth Closed circulatory system The heart is divided into three chambers

CLASS REPTILIA

Example : Snake , lizard and tortoise.

Unique characteristics :

Hard,dry horny scales shed periodically 2 pair of legs with five fingers Lungs for gaseous exchange Three-chambered heart(crocodile – four chambered heart)

CLASS AVES

Example : Chicken, eagle, duck

Unique characteristics :

Moved on two feet Forelimbs, with three clawed fingers which can be adapted to form wings Body and wings covered with feathers Adjustable hind limbs for walking, swimming or perching Keratin beaks, with great variety of shapes suitable for different diets Lay eggs

Adaptations to fly :

Wings

Hollow bones which are strong and light Effective respiratory and circulatory systems provide the cells with enough oxygen to

permit a high metabolic rate for tremendous muscular activity to fly Complete digestive system Well-developed nervous system

Other characteristics :

Legs covered with scales No teeth Four-chambered heart Efficient lungs with air sacs No urinary bladder

Major characteristics :

Hair which insulates and protects the body

Mammary glands which produces milk for young

Posses three small bones (malleus, incus, stapes) in the middle ear

Other characteristics :

Skull with two occipital condyle

Upper and lower jaw with differentiated teeth

Outer ear lobes and moveable eye lids

Four limbs for terrestrial adaptation

Lung for breathing and the presence of voice box

Four chambered heart

Exothermic

The presence of urinary bladder

Internal fertilization, where the fertilized egg developed in the female uterus. The

embryonic membrane consists of amnion, chorion and allantois

(i) Order Insectivora -shrew

(ii) Order Chiroptera -bats

ear

fur

tail

nose

whiskers

leg

(iii) Order Dermoptera-flying fox

(iv) Order Carnivora -cat

(v) Order Rodentia - rat, squirrel, mice

(vi) Order Pholidota -pangolin

(vii) Order Lagomorpha -rabbit

(viii)Order Primates –monkey, lemur

(ix) Order Artiodactyls -deer

(B) QUESTIONS & ANSWERS1. Compare the external morphological characteristics of a shark and Selar.

The gill slits of a shark are exposed and visible but Selar fish has a protective bony plate covering their vulnerable gills.

Shark fins are stiff and lack the fine bony spines and muscle control found in Selar fish. Flexible fins mean Selar fish can swim forwards and backwards but sharks are stuck only going forward.

Shark skin is covered by dermal denticles, toothlike placoid scales that are covered with enamel. This design is successful in minimizing drag and maximizing swimming efficiency. Selar fish is covered in flat scales, either cycloid, ctenoid or ganoid, that grow as the fish grows. The rings on these scales can be used to estimate age in Selar fish. However, dermal denticles do not grow with the shark so they can not be used in age estimation.

Both sharks and Selar fish have caudal fins, or tail fins with two lobes. The caudal fin of a shark is considered heterocercal, meaning the two lobes are unequal in size and the vertebral column extends up into the top lobe. Selar fish caudal fins are homocercal, having symmetrical lobes that extend past the end of the vertebral column.

Shark species have eyelids and some can even protect their eye with a tough third eyelid called a nictating membrane. Other species, like the great white shark, have muscles that can roll the eye back into the socket for protection. Selar fish lack eyelids or the ability to protect their eyes.

2. List the differences between Bufo sp. from Rana sp.i. Tadpoles of Bufo sp. are darker than the tadpoles of Rana sp. ii. Bufo sp. has shorter hind legs than the hind legs of Rana sp. iii. Bufo sp. hop, rather than jump like Rana sp. iv. Bufo sp. has dry, warty skin, rather than moist, smooth skin in Rana sp.

3. List the adaptations that enable amphibians to adapt to terrestrial life.i. Soft and moist glandular skin which also function as a respiratory surface for direct

atmospheric gas exchange.ii. Tetrapods, thin webbed feet for crawling.

iii. Double nostrils which open up into the mouth cavity and lead to the lungs. iv. Muscular hind legs for hopping or jumping movement

4. List the advance characteristics of reptiles compared to amphibians.i. Reptiles have a rough brittle exterior made from scales to protect the delicate skin that

lies beneath, which makes them less susceptible to predators but amphibians have non-scaly and smooth skin.

ii. Reptile offspring’s, when born, are sheltered by a hard leathery egg, which insures a leading survival rate. Once developed, the eggs are laid on land or kept in their mothers’ body till hatched. Once they’ve hatched, the young look like miniature adults. Whereas spawn of an amphibian is aquatic larva. Enclosed by a soft gel exterior making them substantial prey for underwater hunters. Amphibians spend the first part of their life in water. There for they’re born with gills and go through metamorphosis to grow lungs and limbs.

iii. Reptiles can grow bigger and easily match the size and height of a man but amphibians are unable to grown larger than the limited size.

5. Compare the beak and feet structure of chicken, eagle and duck.

Aves Beak structure Feet structureChicken Short hard beak Walking feetsEagle Hooked beak TalonsDuck Flat beak Webbed

6. Compare the morphological characteristics of Mammalia and Aves.

Most Mammals has body covered with fur but Aves has body covered with feathers. Mammalia has non-scaly or hairy legs but Aves has scaly legs. Mammalia has teeth and no beak but Aves has toothless beak. Mammalia has hands or paws or hooves but Aves has wings. Most Mammalia give birth but Aves lays eggs. Mammalia feeds its young with milk from mammary glands, but Aves feeds its young by

regurgitating partially digested food.