IX Chapter 7

8/3/2019 IX Chapter 7

http://slidepdf.com/reader/full/ix-chapter-7 1/21

Sir Syed Coaching Academy

IX BiologyChapter-7

INVERTEBRATA

The Kingdom Animalia is broadly divided into two major groups:

i) Invertebrata: Animals without backbone.

ii) Chordata/ Vertebrata: Animals having a backbone (a supporting rod like structure) in

their body.

INVERTEBRATES:

“Animals, which do not have backbone in the bodies, are termed as invertebrates”.

They are greater in number, but usually smaller in size than vertebrates. Invertebrates are divided

into many groups or Phyla. Some of the important phyla are described below:

1)

PHYLUM PROTOZA:

The members of this phylum exhibits following characters:

a) They are unicellular, microscopic eukaryotes.

b) They are either free-living or lives as parasites.

c) Some are autotrophs and some are heterotrophs.

d) Free living protozoans are aquatic either marine or fresh water.

e) Some of the members are useful and some are harmful.

f) Nucleus is well developed and controls all vital activities of cell.

g) They have different locomotory structures pseudopodia, cilia, flagella.

h)

Reproduction is asexual.

Examples: Amoeba, Euglena, Paramecium, etc.

2) PHYLUM PROIFERA:

Following are some characteristic features of phylum porifera:

a) These are the simplest group of Multi-Cellular (Many Celled) animals.

b) There entire body has numeours- pores which are called “Ostia”.

c) The members of porifera are commonly called as “Sponges”.

d) All are aquatic and sessile.

e) They contain an anterior opening called “Osculum”. f) They get their food by filtering of water.

g) They have an internal skeleton of hard structures called “Spicules”.

h) These spicules are made up of CaCO3 or SiO2, to provide support and shape to body.

i) Reproduction is usually asexual.

Examples: Sycon, bath sponge, glass sponge.

3) PHYLUM COELENTRATA OR CNIDARIA:



Following are the common characters found in coelentrates:

a) They are multicellular and aquatic.

b) They are diploblastic because of having two layers, an outer “Ectoderm: and inner

“Endoderm”.

c) Between these two layers, a jelly like non-cellular layer called “Mesoglea” is found.

d) Some members of this phylum are sessile while other is Colonial.

e) They have tentacles for catching of their prey.

f) The mouth open into a hollow space called “Coelenterons”.

g) Reproduction is sexual as well as asexual.

Examples: Hydra, Jellyfish, Obelia, Sea anemone.

4) PHYLUM PLATHYEMINTHES:

Following are the common characteristics of the members of this phylum:

a) They are commonly called “Flat-worms”.

b) They are either free living or parasites.

c)

They are triploblastic.d) They only have mouth but no anus.

e) They are bisexual, having both types of reproductive organ (male and female) in single

body.

f) Some of them developed the structure of suckers.

g) They have special cells called flame cells for excretion.

h) They lay a large number of eggs at a time.

Examples: Planaria, Liver fluke, Tape worm.

5) PHYLUM NEMATODA:

Following are the characteristic features found in nematodes:

a) They are usually called as round worms, as they have cylindrical body with pointed end.

b) They anteriorly have mouth and at posterior end an anus.

c) They have complete and one way digestive tube.

d) They are triploblastic.

e) Sexes are separate and male is slightly smaller than female.

f) They lay a large number of eggs.

Example: Ascaris, Hook worm, etc.

6) PHYLUM ANNELIDA:

Following are the common characteristic features of the member of this class:

a) They all have elongated segmented bodies.

b) They occur in land as well as in water.

c) Most of them are free living but few are parasite.

d) They have well developed systems in their bodies.



e) They respire through their body surface.

f) They have closed type of circulatory system which may contain number of simple

hearts.

g) They have “Metanephridia” for excretion.

h) They are bisexual, asex are not separate.

Example: Earthworm, Leeches, etc.

1) PHYLUM ARTHROPODA:

It is the largest phylum of Kingdom Animalia. Their members contain following characters:

a) They all have jointed legs.

b) Their bodies are covered with a hard covering called “Exoskeleton”, usually made up of

Chitin, CaCo3, SiO2.

c) They occur in land as well as in water.

d) Their bodies can be divided into head, thorax and abdomen.

e) Sexes are separate and reproduction is much rapid.

f) Some of them have wings to fly.

g) They have well developed systems.

Examples: Crab, Cockroach, Butterfly, Prawn etc.

* METANORPHOSIS:

Insects perform a unique type of development to convert themselves from a pre-mature form to

adult stage. This phenomenon is called metamorphosis. Metamorphosis is of two types:

i) COMPLETE METAMORPHOSIS:

In complete metamorphosis, the first step is the “egg” from which young ones which are called

“Larva” hatches out, it feeds actively and then encloses itself in a cover to become “Pupae” after

going through further change, the pupa comes out from its capsule which is then termed as

“Adult”.

Examples: Butterflies, Mosquitoes etc undergo complete metamorphosis.

ii) INCOMPLETE METAMORPHOSIS:

In this type, the first step is also the “egg”, and then a “nymph” hatches out from eggs which

closely resemble with the adult except that its legs, wings and reproductive organs are immature.After the development of wings and maturity of reproductive organs the nymph becomes

“Adult”.

Examples: Cockroaches, Termites, Grasshoppers can undergo incomplete metamorphosis.

1) PHYLUM MOLLUSCA:

Generally all mollusks contain following characters:



a) They all have soft bodies.

b) A membrane called “Mantle” encloses all soft body parts of their bodies.

c) Their bodies are covered externally by a hard covering called “Shell”.

d) They mostly found in water but some are land dweller.

e) A fleshy organ or “foot” is given out of the shell for locomotion.

f) They are classified on the basis of their shell structures.

g) This is the second largest phylum of Kingdom Animalia.

h) Sexes are separate and reproduction is rapid.

Examples: Snail, Squid, Octopus, Sepia etc.

1) PHYLUM ECHINODERMATA:

Following are the common feature of echinoderms:

a) They all have rough spiny skin.

b) They are only found in sea.

c) They are usually pentamerous.

d) They have a unique water vascular system.

e) They can locomote by using tube feet.

f) They do not have head, eyes or even brain.

g) Most of the echinoderms are motile while few are sessile.

Examples: Star fish, Sand dollar, Sea urchins etc.

Sir Syed Coaching Academy

IX BiologyChapter-8

CHORDATA / VERTEBRATA

BASIC FEATURES OF CHORDATES:

Chordates possess the following three characters:

1) NOTOCHORD:

It is a solid elastic rod like supporting structure in the early stage in the embryos of all thechordates. It gives support and stiffness to the body. It persists in few chordates throughout their

life.

2) DORSAL HOLLOW NERVE CORD:

All chordates have dorsal hollow tube like nerve cord. It consists of brain and spinal cord.

3) PHARYNGEAL GILL SLITS:



These appear as paired openings in the walls of pharynx in all the chordates. These help in

breathing. Their basic features are essenbally present in all the chordates during their embryonic

period. Later in adult life they may be modified or even lost.

* VERTEBRATA:

Those chordates which have backbone or vertebral column in their bodies are called

“Vertebrates”. Vertebrates are the group of such characters in which Notochord is replaced by a

series of bones called “Vertebrae” which are arranged in the form of a column called

“Vertebral Column”. Their brain is also protected in a brain bone called “Cranium”.

Vertebrates are usually categorized into following classes:

(i) Pisces (Fishes) (ii) Amphibia (iii) Reptilia (iv) Aves (Birds) (v) Mammalia

1) CLASS PISCES:

Introduction:

Pisces are the largest group of vertebrates with over 25,000 different species.

Characters:

a) Fishes are aquatic animals i.e. found in fresh and marine water.

b) Their bodies are stream lined i.e. spindle shaped which offer Len resistance to water

while swimming.

c) Fishes are cold blooded animals.

d) They respire by gills (in early stages of life), lungs, skin and mucous membrane of

buccal cavity (in adult stage).

e) They have necked skin which is thin, moist and slimy.f) They are cold blooded animals.

Common Examples: Frogs, Toads, Salamanders etc.

a) FROGS:

b) Frog has a necked skin which is smooth, moist slimy and brightly coloured.

c) It jumps very quickly in water while feels danger on land.

d) Frogs lays eggs in water which into tadpole larvae, which under goes metamorphosis to

become a small frog.

e) Frogs bury themselves in the mud present at the bottom of pond, during winter to avoid

low temperature. This condition is called “Hibernation”.

b) TOADS:

Toad has a dry, rough and dull coloured skin and with less jumping capability.

3) CLASS REPTILIA:

Introduction:



The term reptilian means a group of creeping vertebrate. Reptiles include about 5,000 species.

Characters:

a) Most of the reptiles are found on land but few are found in water.

b) They lay eggs on land and eggs are with shell.

c) Their skin is dry, rough and covered with epidermal scales.

d)

They breathe by means of lungs.e) Most of them are cold blooded.

f) The limbs have digits with claws.

g) Both the jaws in reptile bear teeth.

Common Examples:

Wall lizard, crocodile, snake, tortoise, turtle, chameleon etc.

WALL LIZARD:

a) It crawls on walls or even on ceiling, because of special kind of adhesive pads on their

fingers.

b) It feeds on small insects.

SNAKES:

a) Snakes are the limbless reptiles, live on land as well as in water.

b) Some of them are poisonous e.g. Cobra. Poison glands are located near the upper jaws,

which produce poison. White poison of snake is called Venom.

c) Poison is injected into the body of prey through special long pointed teeth called Fangs.

d) Fangs can regenerate if broken while the rest of the teeth are non-poisonous.

e) Most snakes are non-poisonous.

4) CLASS AVES:

Introduction:

Aves are successful and colourful group in the animal kingdom include 9,000 species.

Characters:

a) Their bodies are covered with feathers.

b) Forelimbs are modified to form wings.c) They have melodious voices because of a special sound box which is called syrinx

located at the bone of their neck.

d) They are warm blooded animals.

e) Their bones are long, hollow and light weight.

f) Their eggs are large and covered by a hard shell and contain large amount of yolt.

g) Birds live on land as well as in water.

h) Their mouths are toothless and jaws are prolonged into beat.



Common Examples:

Parrot, Sparrow, Pigeon, Ostrich, Kiwi etc.

PIGEONS:

a) They were used to serve as means of dispatching letters in the old days.

b) Pigeons rearing and flying was once a very common game.

c) Pigeon are among the modern birds which can fly for hour in the air.

KIWI:

a) This bird is found in New Zealand, which has lost the power of flight because wings are

small and weak.

b) Its body is covered with hair like feathers.

c) It has long beak. It is also known as light less bird.

CLASS MAMMALIA:

Introduction:

The term mammalia is derived from a Latin word which means mammary glands. It includes

about 45,000 species.

Characters:

a) Mammals have mammary glands which recreate milk in females while milk is used to

feed their young ones.

b) Their body is covered with hairs.

c) Their skin also contains sweat glands, sebaceous glands and scent glands.

d) They are warm blooded animals.

e) Both jaws (upper and lower) have teeth which are of various types.

f) Most of the mammals give birth to live young ones.

g) Mammals are chiefly terrestrial Whales, Dolphins, Seals in water.

Common Examples:

Elephant, Dolphins etc.

GROUPS OF MAMMALS:

Mammals can be divided into three sub groups.

(i) Egg laying mammals (ii) Pouched mammals (iii) Placental mammals

(i) EGG LAYING MAMMALS:

They are relatively simple among mammals. They lay eggs like reptiles. They have mammary

glands which secrets milk so they feed milk to their young ones. These have characters of both



reptiles and mammals. Hence they are considered to be connecting link between reptiles and

mammals.

(ii) POUCHED MAMMALS:

They give birth to pre-mature babies. They are weak, so their mothers keep them in pouches

which are present on the belles, until they develop fully and become strong enough for

independent life. Inside the pouches babies get milk through mammary glands.

Common Examples:

Koala bears, Opossums, Kangaroos etc.

(iii)PLACENTAL MAMMALS:

In placental mammals the young one completes its development inside the body of its mother,

where it is feed through an organ called placenta. The mammal gives birth to full mature babies.

After the birth, the young one gets nourishment through mother’s milk secreted from the

mammary glands.

Common Examples:

Women, Monkeys, Elephants, Cats, Rat, Lion, Bats, Whales, Dolphins etc.

HABITAT OF MAMMALS:

Although mammals are chiefly terrestrial, some e.g. Whales, Dolphins, Seal, etc. live in water.

Blue Whales are the largest living animals in the world. Bats are unique as they can fly.

SOME INPORTANT TERMS:

(i) DUAL LIFE OF AMPHIBIANS:

Amphibians live in water during their early life. While in adult life, they live in water as well as

on land due to this reason they are regarded as having dual life (or Amphibia).

(ii) COLD BLOODED ANIMALS:

Those animals whose body temperature does not remain constant i.e. their body temperature

varies with the temperature of external environment are called cold blooded animals.

Examples: Amphibians, Reptiles and Fishes.

(iii) WARM BLOODED ANIMALS:

These animals whose body temperature does not change i.e. remains constant or does not vary

with temperature of the external environment are called warm blooded animals.

Examples: Mammals and Birds.

(iv) HIBERNATION:



During winter in order to avoid low temperature, frogs burry themselves into the mud present at

the bottom of pond. This phenomenon is called hibernation and also called winter sleep.

(v) AESTIVATION:

During summer when amphibians undergoes sleeping is called aestivation or summer sleep.

(vi) OPERCULUM:

The bony plates or flap like structures covering and protect the gills of fish are called Opercula.

(singular Operculum).

(vii) FANGS:

Special long pointed poisonous teeth of snake through which it injects poison into the prey are

called Fangs.

FLORA OF PAKISTAN:

FLORA:

Simply meaning plant life. Different kinds of plants found in a particular area which contains its

flora.

FLORA OF HIGH MOUNTAINS:

The high mountains in the North and North Western parts of Pakistan have sufficient snow fall

and low temperature. The mountains have thick forests. These forests have trees like Blue Pine,

Chilghoza Pine, Deodar, Junipers, Fir, Oak and Olives.

FLORA OF DESERTS:

Deserts plants are situated in the area where there is less rain fall and scarcity of water. Plants are

mostly xerophytes like acacia, Prosopis and Capparis.

FLORA OF IRRIGATED PLANTS:

Like Changa Manga these provides trees of Sheesham, Mulberry, Willow, Poplar, Neem etc.

which provide woods for furniture, sports goods and fuel.

FLORA OF PLAINS:

In the plains many crops are cultivated for nutritional and other requirements. These plants

include Wheat, Maize, Rice, Sugarcane, Sugar Beet, Pea, Potatoes, tomatoes, Onion, Garlic,

Chilies, Turnips, Radish, Carrot, Cauliflower and many general grains and cotton etc.

FLORA CONSTITUTED FRUITS:

Pakistan is also rich in fruit trees such as Mangoes, Apples, Oranges, Apricots, Peaches,

Bananas, Walnuts and Almonds etc.

FLORA CONSITS OF ORNAMENTAL PLANTS:



Many plants are cultivated for ornamental purposes. These includes Chrysanthemum, Roses,

Jasmine etc.

FLORA FOR FOODER:

The hills and plains of Pakistan possess different kinds of grasses which provide fodder for

grazing animals.

FLORA OF FRESH WATER:

A large number of plants are present in fresh water ponds, lakes, streams and rivers of Pakistan

such as Hydrilla, Typha and many different kinds of Algae etc.

FLORA OF MARINE WATER:

Similarly many plants and algae are found in oceans and coastal regions of Pakistan i.e. sea

weeds, ulna etc.

IMPORTANCE OF FOREST AND FLORA:

a) Forests are forestry are considered the backbone of our country.

b) Forest regulate supply of water in rivers by blocking its free flow especially during heavy

rains so forest control floods.

c) They prevent loss of top soil by holding it with their roots.

d) Forest prevent formation of deserts, water logging and control the amount of salt in soil.

Plants supply oxygen and clean the air.

e) They provide shelter and food to wild life. They are integer part of ecosystem.

Some of the economically important flowering and non-flowering plants of Pakistan are

discussed as follows:

(i) Coconut tree (ii) Rose plant (iii) Neem tree

(iv) Mango tree (v) Banana tree (vi) Date tree (vii) Papaya tree

FAUNA OF PAKISTAN:

Fauna:

Simply meaning Animal life. Different types of animals found in a particular region which

constitute its fauna. Different groups of animals are found in different areas of Pakistan. Each

one of these groups holds an important position in its Biological relationship with plants andwith human being.

COASTAL FAUNA:

Sind and Baluchistan are rich in sea foods and are considered to be one of the best fishing ground

in the world. In Pakistan more than 1,000 species of edible fishes are found. The most common

are Rohu, Pallah, Khagga, Trout, Mahaseer, Flat fish, Mallee, Mushka and Pomfert. Other fauna

includes Skates, Sea-horse, Rays, Sharks, Scolidan (Dog Fish), Crabs, Lobster, Prawns, Octopus,

Star, Star fishes, Jelly fishes, Sea-inchins, Mussels and Snails.



AMPHIBIANS FAUNA:

Common Amphibians like Frogs and Toads found in Pakistan.

REPTILIANS FAUNA:

Reptilian fauna included Turtles, Crocodiles, Lizards (Wall lizards, Garden lizards and Monitor

lizards), Snakes and Cobra, Krait, Vipers and Phytons are commonly found.

AVIANS FAUNA:

Pakistan is rich in a variety of birds fauna but we do not have flight less birds. Falcons, Eagles,

Kites, Vultures, Hawks and Owls constitutes a group of birds of prey. Pheasant like Peacocks,

Quails, Partridges, Chukors, Crows, Parrots and Doves are the common birds. Every year a large

number of birds visits Pakistan such as Flamingoes, Spoon bills, Mallards, Pilchard, Pelicans and

many other water birds.

MAMMALIANS FAUNA:

Mammalian’s fauna make up by a major part of our wild and domesticated animals.

CARNIVOROUS MAMMALS:

They include Wolves, Jackals, Foxes, Leopards, Mangoose and Bears. We have lost Tigers and

Loins due to hunting them.

HOOFED MAMMALS:

They include wild Goats (Ibex), Sheeps, Deers, Gazelles, Markhor, Cows, Donkeys, Horses and

Camels are common domesticated forms. Some of them provide us milk and meat.

ENDANGERED SPECIES:

Our Rhesus Monkey is endangered due to its great demand in overseas markets. Grey Langur,

Markhor, Snow Leopard, Wolf, Sindh Ibex are also endangered species (animals) of Pakistan

due to uncontrolled hunting.

Sir Syed Coaching AcademyIX Biology

Chapter-8

RESPIRATION

RESPIRATION:

Definition:



“A process that liberates chemical energy from organic molecules when oxidized”.

These organic molecules are food substances which obtain from the environment. This energy is

utilized to perform all the body functions such as cell divisions, growth, movements etc.

Respiration is a complex two step process breathing and cellular respiration or simply

respiration.

(i) BREATHING (OR) GASEUOS EXCHANGE:

The process of take in and take out of a different gasses through respiratory structure is known as

breathing.

(ii) CELLULAR (OR) SIMPLY RESPIRATION:

The process of oxidation of food which takes place within the cells by the help of oxidative

enzymes for the production of energy.

NOTE ON ATP (Adenosine Triphosphate):

These are energy rich molecules produced in the cell during cellular respiration by the help of

mitochondria. Cells can only use energy in the form of ATPs so they are often called as

“Currency of Energy” of cell.

STRUCTURE OF ATP:

Each ATP molecule chemically consists of an organic component adenine linked to a ribose (5

Carbon sugar) to form Adenosine to which is attached a chain of three inorganic Phosphate

groups.

IX Chapter 7

Documents

Transcript of IX Chapter 7