Download 4. BACTERIA, FUNGI AND PLANTAE Unit

Core Experiments:
Unit - 2
In this unit you will study the museum specimen or slides of examples belonging to
different groups such as bacteria, fungi, plants and animals. While doing this, you have to
identify, classify and write comments on the specimens you observe. According to the syllabus
the slides and specimens will be available in the school laboratory but if you get the
opportunity to see them live then observe carefully. If you see plant specimens during your
trip then collect them and prepare them slides and specimens.
In the following pages every slide / specimen given in the syllabus have been described
and some additional easily available examples have been given. Under ferns your syllabus
suggests selaginella but Pteris and Dryopteris are more easily available. Among the animals
instead of snails, the pond snail Pila is more easily available. Among the birds the common
house sparrow instead of pigeon, common house lizard, among the reptiles and among the
mammals the house rat other than rabbit have also been described. Try to observe the
characteristics mentioned in the lab manual, draw labelled diagram and write comments
on them. In the following pages every specimen has been classified and the identifying feature
of every group has been given in brackets - pay more attention to these.
4. BACTERIA, FUNGI AND PLANTAE
Comments:
(i)
Bacteria are very minute organisms. (Its
diameter in less than 3 microns and size
is 1 to 80 microns). They may be
spherical rod shaped, spiral shaped,
filament like and comma shaped.
(ii) It’s cell is prokaryotic type that is nucleic
acid are scattered in the protoplasm. The
nucleus has no nuclear membranne.
(iii) Some bacteria have flagella.
(iv) The cell has a rigid cell wall. The cell
wall is made up of peptidoglycane and
not like plant cell which is made of
cellulose.
(v) It has no plastids.
(vi) Asexual reproduction is by amitosis.
(vii) They can normally survive in the
temperature ranging from 75-800C to 1900C.
1. BACTERIA
Identification and Classification :
Bacteria are ultramicroscopic monerans. The body
is a prokaryotic cell.
Kingdom - Monera (Prokaryotic)
Phylum
- Schizomycetes (all type of
bacteria).
Class
- Eubacteria (cell is surrounded
by cell wall and has not true
nucleus).
2. OSCILLATORIA
Identification and Classification:
These are filamentous blue green algae. These are
simple structured monerans. Their classification
is as follows :
Fig. 4.1 Typical Bacterium (Rod shaped)
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CORE EXPERIMENTS
Kingdom - Monera (Prokaryotic)
Division - Cyanophyta (Blue-green algae)
Genus
- Oscillatoria (filamentous blue
green algae).
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Kingdom - Plantae (Eukayotic, multi-cellular
algae).
Division
- Chlorophyta (Green AlgaeChlorophyll a and b present).
Genus
- Spirogyra (Rectangular cells
having spiral chloroplast).
Fig. 4.2 Oscillatoria
(A) A few filaments.
(b) Magnified view of a filament.
Comments:
(i)
These are commonly found on the surface
of moist walls, pots, water falls, ponds,
lakes etc. These are also found in the
stagnant water of ponds where the other
algae are not found.
(ii) The body is cylindrical, filamentous and
unbranched. The filaments have no
sheath like other blue-green algae.
(iii) The upper part of the filament is
generally straight but can also be round
or bent (like sickle or screw).
(iv) Oscillatoria filaments can move,
oscillate, twist or rotate on one place.
(v) There are vacuoles in the cytoplasm.
(vi) The asexual reproduction is by
separation of filament or by formation
of hermogonia.
3. SPIROGYRA
Identification and Classification:
It is found in fresh water of lakes and is filamentous
green algae. Its rectangular cell contains spiral
ribbon shaped chloroplast which is the main
distinguishing character. The classification is as
follows:
Fig. 4.3 Filaments of Spirogyra
Comments:
(i)
It is found as a filament floating in the ponds,
springs and between scum of slow flowing
rivers.
(ii) Each filament is unbranched, smooth and
green in colour. Length of filaments can
reach upto few inches.
(iii) The cells of teh filaments are rectangular
and are linear.
(iv) In the centre of each cell is a nucleus
and cytoplasm is present as radiating
stripes. Therefore, vacuoles are divided
into compartments.
(v) Green chloroplast is flat and spirally
coiled like a ribbon.
(vi) Only sexual reproduction takes place,
which is completed by lateral
conjugation or scalariform conjugation
methods. Sometimes due to breaking of
filaments asexual reproduction also
takes place.
(vii) They synthesise their food by
photosynthesis that is why they are
known as autotrophic.
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PRACTICAL BIOLOGY - XI
4. RHIZOPUS
(The Bread mould)
Identification and Classification:
This black coloured fungus is usually found on
moist bread, decaying vegetables, fruits, jelly etc.
This is similar to pinfungus that is Mucor. The
classification is as follows:
Kingdom - Fungi (Without chlorophyll,
eukaryotic, multinucleated cell,
hetrotrophic)
Division - Zygomycota
(Sexual
reproduction by conjugation
hence also known as
conjugation fungi).
Genus
- Rhizopus
(Blackish
filamentous, branched fungi
which grows on bread).
(b)
Roots like rhizoids - which penetrate into
the food materials to digest and absorb
it,
(c) Sporangiophores - which grow erect on the
bread surface. Each hyphae bears
sporangium at the tip. When these
sporangia burst, large number of spores
are spread which grow when they get
favourable conditions.
(iii) The sexual reproduction takes, place like
Spirogyra by conjugation method.
5. MUSHROOM
Identification and Classification:
Commonly known as Toad’s stool. It’s shape is
like an umbrella and grows on wood and decaying
matters. the classification is as follows:
Kingdom - Fungi (Chlorophyll absent,
eukaryotic, multinucleate,
hetrotrophic).
Division
- Basidiomycota (Reproduction
by club shaped basidia).
Genus
- Agaricus
Fig. 4.4 Rhizopus
Comments:
(i)
(ii)
(a)
It grows on bread, jelly, fruits etc. Blackish
in colour and that is why it is known as Black
Bread Mould.
The body of the fungus is formed by many
white or ash coloured mycellia. Number of
fine branches (branched structures) come
out of the mycelium, called hyphae they are
of 3 types On the surface of the bread net like hyphae
(stolon),
Fig. 4.5 A. Mushroom (Agaricus)
Comments:
(i)
(ii)
Mushrooms are macroscopic, fleshy,
umbrella like forms.
They grown on rotten logs of wood, tree
trunks, decaying organic matter rich in
organic compounds.
CORE EXPERIMENTS
(iii)
Several varieties of this are used as food. It
is rich in minerals and believed as nutritive
food. Some of the species are poisonous
also.
(iv) Some portion of the mushroom body is
embeded in the ground or substratum on
which it grows. Inside there are plenty
of branched hyphae. Above the ground
a stalk is visible which has cap like
expanded umbrella known as pileus. The
lower side of the cap has thin vertical
plate shaped structures called gills.
(v) The stalk and the umbrella are fleshy and
are interwoven with each other by
number of hyphae. On the top of the gills
of umbrella reproductive organ are
present known as basidia from which
basidiospores are formed. These are
clubshaped structures. That is why it is
known as Club Fungi.
(vi) The mushrooms, used for eating purpose
are nowadays grown in large quantities.
6. YEAST
Identification and Classification:
Yeast are microscopic fungi. The Classification is
as follows:
Kingdom- Fungi (Chlorophyll absent,
eukaryotic, multinuclear cell,
saprophytic).
Division- Ascomycota (Spores produced in
ascus).
Genus - Saccharomyces (Unicellular
which grow in sugar medium).
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Comments:
(i)
This fungus is usually found in sugar
containing substances like date palm
fluid, soil of grape orchards and grapes.
(ii)
It is unicellular and microscopic in size.
(iii) The cell is oval in shape with specific
vacuoles present in nucleus.
(iv) Cytoplasm consists of stored food
vacuoles.
(v)
Cell wall is distinct, rigid and made up
of chitin.
(vi) Asexual reproduction takes place by
budding and ascus formation.
(vii) In some species sexual reproduction
takes place by conjugation.
(viii) It has the capacity to convert
carbohydrates into alcohol. This action
is known as fermentation.
(ix) The spongyness of bread is due to the
release of carbondioxide by yeast.
(x)
Due to enormous vitamin contents yeast
is also good as medicine.
7. LIVER WORT
Identification and Classification:
Commonly found growing on moist and
shady walls, these flat ribbon shaped green
plants are seen to cover the whole ground. They
hold the soil with the help of rhizoids. It
resembles the liver of animals and hence it is
called liver wort. It has many genera like
Riccia, Marchantia etc. The classification is
as follows :
Kingdom- Plantae (Green, multicellular,
autotrophic).
Fig. 4.6 Yeast Cell
Division- Bryophyta (Vascular tissue is
absent, gametophytic stage is
present).
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Class
PRACTICAL BIOLOGY - XI
- Hepaticeae (Prostrate thalloid body).
Genus - Riccia
Comments:
Identification and Classification:
In the rainy season the moss plants can be
seen like green carpets on the moist walls and
grounds. Classification is as follows:
Kingdom - Plantae (Green, multicellular,
autotrophic).
Division - Byrophyta (Vascular tissue is
absent, gametophytic stage is
dominant).
Class
- Musci (erect like the flowering
plants).
Fig. 4.7 Riccia
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
They are simple plants having flat thalloid
body (Ribbon shaped). The thallus is
divided into two branches from each side
and therefore the thallus is rosette shaped.
It is found on moist soil and in humid
atmosphere.
On the lower surface of the thallus
rhizoids are present by the help of which
it fixes itself to the soil. True roots are
absent.
Vasular tissue xylem and phloem are
absent.
Dorsally the thallus has number of cup
like outgrowths called gemmae.
Vegatative propagation takes place with
the help of these gemae.
Main plant is gametophyte, therefore it
develops male reproductive organ
antheridium and female reproductive
organ archegonium.
Male and female gametes are produced
for sexual reproduction. Oospores
develop into sporophyte. Asexual
reproduction is by producing spores in
sporophyte. Spore produces haploid
gametophyte. In this way alternation of
generations takes place.
8. MOSS (FUNARIA)
Genus
- Funaria
Comments:
Fig. 4.8 Moss Plant
(i)
Funaria is commonly found on moist tree
barks, moist walls or other moist places.
(ii) It is about 2 to 3 cms. tall plant. Main
plant is in gametophytic stage. From the
apex of the main plant sporophyte is
developed.
(iii) Gametophyte of moss remains attached
to the ground with the help of rhizoids.
The stem is like an axis and may be
branched or unbranched. It bears flat,
green spirally arranged leaves, which are
abundant towards apex. True root or
stem is absent.
(iv) The sporophyte consists of a foot, seta
and capsule.
CORE EXPERIMENTS
(v)
(vi)
Capsule is covered by operculum. Spores
develop in the capsule. Gametophyte
develops from spores.
Like Riccia they also show regular
alternation of generations in their life
cycle.
9. FERN
Identification and Classification:
The fern plant grows in the cool moist place
having pinnately compound leaves. They are
grown as ornamental plants in the garden. The
classification is as follows:
Kingdom - Plantae (Green, multicellular,
autotrophic).
Division - Tracheophyta (Vasular tissue
present).
Subdivision- Pteriodophyta (Plant is divided
into true root, stem & leaves).
Genus
- Dryopteris
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can be grown in pots.
(ii) The plant is in sporophytic stage.
(iii) Plant is distinguished into root, stem and
leaves. Some type of ferns are prostate
but majority are erect like flowering
plants.
(iv) Stem is underground roots are
adventitious. Stem grows parallel to the
ground in the form of rhizome which
bears leaf on it.
(v) The leaves are pinnately compound.
Each leaf has a rigid, scaly petiole which
is prolonged to form rachis that bears two
rows of leaflets called pinnae.
(vi) The underside of leaf pinnae has
sporangia by which spores are produced
through asexual reproduction.
(vii) Spores grow and develop heart shaped
gametophyte which by sexual
reproduction produce sporophtye. Hence
fern plants also show alteration of
generations.
Comments:
10. SELAGINELLA
Identification and classification :
This is found in the plains and hithy
regions where the climate is humid. Quite
commonly grown in gardens and plant
nurseries. Its classification is as follows :
Kingdom -
Plantae (green, multicellur,
autotrophic)
Division -
Tracheophyta (Vascular tissues
and embryo present)
Sub division -Pteriophyta (plants divided
into true roots, stem, leaves)
Genus -
Selaginella
Comments :
Fig. 4.9 Fern Plant (Dryopteris)
(i)
Fern plants commonly grow in cool, moist,
high altitude places. In tropical climates it
(1)
Found in cold, humid places like other
ferns.
(2)
Plant is a sporophyte.
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PRACTICAL BIOLOGY - XI
Identification and Classification:
spike
leaf
Pinus is a tall, evergreen, cone shaped tree
found mostly on high altitudes and cool
mountain areas. Some species of Pinus are also
grown in gardens and pots.
Classification is as follows:
Kingdom - Plantae (Green, multicellular,
autotrophic).
rhizophore
Fig. 2.1 Selaginella
(3)
Plant body differentiated into stem, root and
leaves. It spreads on walls or the soil in the
form of a creeper.
(4)
The stem is cylindrical with four rows of
leaves. Two rows of small leaves are
situated on the upper surface and two
rows of bigger leaves are present on the
two sides. At the base of the stem scaly
ligules are present.
(5)
Root like structures arise from the stem
called rhizophores.
(6)
Plant bears two types of sporophylls
which are situated in cones on unisexual
or bisexual plants. On the same cone or
on two different cones, the two types of
sporophylls are found.
(7)
The spores fall four the sporophyte and
give rise to male and female
gametophyle. The male and female
gametophytes reproduce by sexual
reproduction to give rise to the
sporophyte.
11. PINUS
Division
- Tracheophyta (Vasular tissue
present).
Subdivision- Spermopsida (Flowering and
seed producing).
Class
- Gymnospermae (naked seed
plants)
Genus
- Pinus (needle shaped long leaf).
Comments:
Leaf
Stem
Cone
Fig. 4.10 Pinus Tree (A portion)
(i)
The tall cone shaped pinus trees grow at
the height of about 10,000 feet on the
Eastern and Western Himalayan region.
(ii)
Pine tree can grow upto 125 feet & the
stem upto 8-9 feet in diameter.
(iii) The tap root is well developed and
CORE EXPERIMENTS
(iv)
(v)
(vi)
15
number of branches emerge from the stem.
The stem is covered by scales which
separates out in the form of bark. Needle
like leaves are present on the shoots.
Kingdom - Plantae (Green, multicellular,
autotrophic).
There are two types of shoots - long shoots
or the branches of unlimited growth and
dwarf shoots or the branches of limited
growth. Needle shaped leaves are present
on the dwarf shoots. Scaly leaves are
present on both types of shoots.
Subdivision- Spermopsida (Flowering and
seed bearing plant).
The main plant shows sporophytic stage. It
develops male and female cones by asexual
reproduction. These are also known as male
and female strobila.
Male cones grow every year on the apex
of each shoot in a group and are about 1
inch long.
Division
- Tracheophyta (Vasular tissue
present).
Class
- Angiosperm (fruits enclosing
seeds)
Subclass
- Monocotyledoneae (monocot
plants)
Genus
- Allium
Species
- cepa
Comments:
(i)
This monocot plant grows underground.
(ii)
The stem is modified into a bulb. Food is
(vii) Female cone grows singly or in a group
of 2-3 and is about 2 to 4 inches long.
(viii) Gametes develop from male and female
cones. Embryos are formed by sexual
reproduction. Fruits are not formed,
hence seed are naked and exposed.
Therefore, plants are known as
“Gymnosperm”.
(ix) Pine tree is of much economical
importance.
12. A MONOCOT PLANT ONION
Fig. 4.11 Onion Plant
Identification and Classification:
Monocot plants can be easily recongnised by
adventitious roots and long narrow leaves.
palm tree, lilly plants, onion, garlic, wheat,
maize, banana etc. are monocot plants ie. they
have a single cotyledon in their seeds. As an
example of a monocot plant, onion is described
below. The classification is:
stored in the bulb. An ariel stem is developed
from the bulb which is called scape. A bunch
of flower grows on this scape. Bulb is
underground.
(iii)
From the base of the bulb (stem) number
of adventitious roots are developed.
(iv) From the apex of the bulb number of
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PRACTICAL BIOLOGY - XI
elongated cauline leaves develop. The base
of the leaves form fleshy part of the bulb.
Comments:
(i)
Mustard plant is grown as rabi crop.
(v)
It has no branches.
(ii)
(vi)
No leaves are present on the scape. On
the apex of the scape a bunch of flowers
make an umbellate type of inflorescence.
The root system, stem and leaves are well
developed.
(vii) Each flower has two circles of 3 white
petals. Female reproductive organs
containing ovary, style and stigma are
present inside the flower. 6 stamens are
present as male reproductive organs. The
ovary has 3 ovules.
(viii) It is used as a vegetable and has many
medicinal properties, due to which it is
a economically very important plant.
13. DICOT PLANT - MUSTARD
Identification and Classification:
The trees and plants found in the gardens, on the
road sides, fields, mountains, bushes and most of
the flowering plants are mostly dicots. The plants
with seeds which have 2 cotyledons are known
as dicotyledens. gram, pea, mustard, ground nut,
neem, mango, guava, pepal, teak etc. are included
in the dicot category. Mustard plant is described
here a typical dicot plant. The classification of a
dicotyledon plant is:
Kingdom - Plantae (Green, multicellular,
autotrophic).
Division
- Tracheophyta (Vasular tissue
present).
Subdivision- Spermopsida (Flowering and
seed bearing).
Class
- Angiospermae
Subclass
- Dicotyledonae (Dicot plant)
Genus
- Brassica
Species
- juncea
Fig. 4.12 Mustard Plant
(iii)
It contains main root that bears branches
on lateral sides - tap root system.
(iv) Stem is long, erect, solid, tubular and
green in colour. On the lower parts of
the stem the leaves are arranged in a
linear fashion. On the upper region
flowers and fruits are also arranged in
the same way.
(v)
Leaves have petiole with narrow base
and are broader towards the apex. Leafmargins are incised.
(vi) On the upper end of the stem fruits are
present as pods. The pods contain yellow
mustard seeds. Seeds are spread when the
pod bursts.
(vii) Flowers are yellow and attractive. It has
four sepals and four petals. In the centre
of flower, a long pod like ovary, small
CORE EXPERIMENTS
17
styple and a round top known as stigma
is present. 6 stamens attached to the
thalamus surround the ovary. Pollen
grains are present on the apex of the
stamen.
(viii) Edible oil is obtained from the seed, hence
it is a commercially important plant.
14. LICHENS
Lichen plants grow on moist stones and
barks of trees and appear in patches. It is a group
which represents symbiotic association between
alga and fungus.
Usually symbiotic association is between a
fungus from Ascomycota or Basidiomycota
Fig. 4.13 Different types of Lichens
divisions and chlorophyta (green algae) or
(A) Parmellia (B) Cladonea (C) Usnea
mycophyta (Blue green algae). Hence the
classification of lichens is done according to the
type of fungus present. Hence, these can be
ascolichen or basidiolichen. In their symbiotic
associationship algal filaments perform
lichens are the first to appear. The soil formation
by these helps in growing moss and fern plants in
that area.
photosynthesis and fungus provide protection to
Some lichen are used for feeding animals.
algae. If blue green algae are present then these
Some have medicinal value. the litmus used for
perform nitrogen fixation also.
finding the pH value is obtained from lichens.
Lichens can be or various shapes (i)
Broad & Flat
- Crustose Lichen
(ii)
Leaf like
- Foliose Lichen
(iii)
Branched
- Fruiticose Lichen
In a place where no vegetation grows,
Many varieties of litmus paper, aromate
substances and tannings are also prepared from
lichen. Main examples of lichens are :
(i)
Granular Lichen, Graphis
(ii)
Beared like lichen, Parmellia
(iii)
Bread like lichen, Usnea
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PRACTICAL BIOLOGY - XI
5. ANIMAL FORMS
1. AMOEBA
Identification and Classification :
It is a microscopic, unicellular organism. Its body
is infact a eukaryotic cell. They move slowly by
forming temporary structures called pseudopodia.
Kingdom - Animalia (Eukaryotic cellular
organism)
Phylum
- Protozoa
microscopic,
nutrition)
(unicellular
holozoic
Class
- Rhizopoda (Locomotion by
pseudopodia)
Genus
- Amoeba
Species
- proteus
(vi) There is a prominent nucleus and a
contractile vacuole. Some food vacuoles
present as stored food.
(vii) It exhibits holozoic nutrition.
(viii) Reproduces only by asexual methods binary or multiple fission.
(ix) When the pond water dries, they are
surrounded by a cyst for protection. This
is called as encystment. When the
favourable conditions are resumed they
come out of teh cyst. Amoebae do not
die of a natural death because they go
on dividing and forming new amoebae.
Therefore, it is considered as an
immortal organism.
Comments:
2. SPONGE
Identification and classification :
It is a sponge of simple structures. Its
classification is as follows :
Kingdom - Animalia (multicellur, haterotrophic)
Phylum -
Porifera (pores present, no tissues)
Class -
Calcarea (calcareous spicules
present)
Found in ponds, ditches, lakes etc. Its
proteus species is very common.
Genus -
Leucosolenia
Live an independent life.
1.
Found on sea shores sticking to objects.
2.
They live in colonies.
3.
Body cylindrical. At the base of the colony
branches join each other to form a network
like structure.
4.
At the distal end of the branch large
osculum present.
Fig. 5.1 Amoeba
(i)
(ii)
(iii) Irregular in shape. Cell itself is its body.
(iv) Protoplasm is distinguished into an outer
ectoplasm and an inner endoplasm.
Protoplasm is seen protruding in
different directions in the form of
pseudopodia.
(v)
Locomotion is done by putting forth and
withdrawing these pseudopodia.
Comments :
CORE EXPERIMENTS
19
osculum
Mouth
Hypostome
ostia
Teutacle
Bud
base
Body
substratum
Fig. 5.2 Hydra
Fig. 2.2 Leucosolenia ( A sponge)
5.
The body cavity is called spongocoel.
6.
The body surface has numerous ostia.
Water enters the body constantly through
the ostia and leaves the body through the
osculum. This forms a special kind of
canal system.
7.
It is through the water entering the canal
system, nutrition, respiration and
excretion are carried out.
8.
Reproduction both by asexual and sexual
methods.
9.
They show great power of regeneration.
3. HYDRA
Identification and Classification:
Kingdom - Animalia (multicellular,
heterotrophic)
Phylum
- Coelenterata
gastrovascular
diploblastic)
(hollow
cavity,
Class
- Hydrozoa (Simple body cavity)
Genus
- Hydra
Comments:
(i)
It is found in ponds, pools or ditches
filled with water and is attached to some
object. Sometimes it moves also.
(ii)
Body is cylindrical & elastic.
(iii)
The distal end is free and has a small conical
projection called hypostome having at star
shaped mouth opening.
(iv)
Surrounding the mouth are 6-10 tentacles.
The tentacles possess nematocysts.
(v)
The mature Hydra may have a bud near
the base and gonads in the middle of the
body.
(vi)
With the help of tentacles and nematocysts
it catches the prey.
(vii) It reproduces by asexual and sexual
methods. In the asexual reproduction the
buds come out of the body and move away
by separating themselves from the parent
body.
(viii) It has a great power of regeneration.
(ix)
It exhibits symbiosis with algae present in
the water.
4. LIVER FLUKE (Fasciola)
Identification and Classification:
Kingdom - Animalia (Multicellular,
Helerotrophic)
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PRACTICAL BIOLOGY - XI
Phylum
- Platyhelminthes (Triploblastic,
acoelomate, flat worms)
Class
- Trematoda (Unsegmented flatted
parasites.)
Genus
- Fasciola (Leaf shaped, endopara
sites in liver)
of the body bears an excretory pore.
(vii) Its colour is light rosy and it is semi
transparent. Therefore, digestive canal
and vitelline glands can be seen from
outside.
5. ASCARIS
Identification and Classification:
It is thead like intestinal parasite. It is multicellular,
bilaterally symmetrical and pseudocoelomete.
Kingdom - Animalia (Multicellular,
heterotrophic)
Phylum
- Nemathelminthes
(Triploblastic,
pseudocoelomate)
Class
- Nematoda (Round worm,
unsegmented parasites).
Genus
- Ascaris
Fig. 5.3 Fasciola hepatica
Species
- hepatica.
Comments:
(i)
Dorsoventrally flattened and leaf like body
hence called ‘flukes’.
(ii)
It is an endoparasite in the bile passage of
vertebrates like sheep, cow, pig etc., It
completes the life cycle in two hosts therfore
it is knows as digenetic parasits.
(iii)
Its hepatica species makes sheep its
primary host and a Gastropod mollusce
as secondary host.
(iv) These are 1.8 cms to 3 cms long and the
maximum width at the centre is 0.5 to
1.5 cms.
Species
(v)
Comments:
Outer covering is thick and smooth.
(vi) A mouth opening present at the anterior
end which is surrounded by an oral
suckers a little below the mouth. On the
ventral side, close to the acetabulum a
gonopore is present. The posterior end
Fig. 5.4 (A) Male and (B) Female Ascaris
- lumbricoides.
(i)
It is an intestinal parasite of human beings.
The most common species is lumbricoides.
(ii)
The body is round slender and tapering at
both the ends. When it is alive the colour is
CORE EXPERIMENTS
21
light rosy or yellowish white.
(iii)
The animal shows sexual dimorphism with
separate male and female individuals.
(iv)
Males are smaller in size than the females.
Male is 15 to 30 cms. in length & 2.4 cms
in breadth. Female is 20 to 50 cms in length
and 3 to 6 cms in breadth.
(v)
Posterior end of the male is curved having
cloacal aperture and penial setae.
(vi)
Female Ascaris has genital aperture at 1/3
of the anterior ends.
Class
- Hirudinea (Definate number of
body segments, suckers on both
ends, setae absent)
Genus
- Hirudo (Ectoparasite
vertebrates)
Species
- medicinalis
of
(vii) The male and female have 2 lateral lines
from one end of the body to another. In
addition to this there is one white line
(mid dorsal line) on the dorsal side.
Similarly, there is a mid ventral line on
the ventral side.
(viii) It is a harmful parasite for man. It is
commonly found in children. To reach
from one host to another, it passes
through the intestine and various other
organs and thus damages them. In the
mature stage it blocks the intestine. The
presence of this causes stomachache,
indigestion, loss of apetite, diarrhoea,
appendicitis, anaemia and the host
becomes very weak.
Fig. 5.5 Leech
Comments:
(i)
The most common species is H. medicinalis,
which is found floating on water in ponds,
swamps and is an ectoparasite on buffalow,
fish, frog, human beings and other animals.
It is named medicinalis, because in the olden
days it was used to suck the blood from
injuries.
(ii)
It sucks the blood of its host.
(ix) The larva reaches another host through
contaminated water by faecal matter.
6. LEECH (Hirudo)
Identification and Classification:
The fresh water ectoparasite feeding on the blood
of vertebrates. The segmented, elongated and
flattened organism is classified as follows:
Kingdom - Animalia (Multicellular,
hetrotrophic)
Phylum
- Annelida
Coelomate)
(Segmented,
(iii) It is 10 cms long but after sucking the
blood. it measures up to 20 to 30 cms.
(iv) They are yellowish brown organisms and
are flattened dorsoventrally. The body is
divided into 33 true segments. It is broad
at the posterior end. The body segments
are sub divided into 2-5 subsegments.
Therefore, it is difficult to count the
segments.
22
(v)
(vi)
PRACTICAL BIOLOGY - XI
There is one sucker each on posterior and
anterior end. The anterior sucker is round
and is on the ventral surface. In the centre
of this is mouth opening. The porterior
sucker is large, round and is like a disc.
On the base of posterior sucker, anus
opens dorsally.
Clitellum
Genital papillac
They are hermaphrodite. There is a made
genital pore in the 10th segment and a
female genital pore in the 11th segment.
7. EARTHWORM
Identification and Classification:
Earthworm is a segmented animal. It has a
prominent band like structure, clitellum in the
anterior part. The integument is provided with
setae.
Kingdom- Animalia
(multicellular,
heterotrophic)
Phylum - Annelida
(segmented,
eucoelomate, triploblastic)
Class - Oligochaeta (setae for locomotion)
Division- Ascomycota (Spores produced in
ascus).
Genus - Pheretima (Earthworm)
Species - posthuma
Comments:
(i)
It burrows hole in the earth and that is why
it is known as Earthworm.
(ii)
The Indian species posthuma is brown
coloured.
(iii) On the top of the burrows excreta is
deposited in the form of pellets. The
presence of pellets indicates its presence
in the soil.
(iv) It is elongagted, cylindrical and
segmented. There are about 100-125
segments.
(v)
In the first segment lies the mouth and
in the last segment lies the anus.
Fig. 5.6 Fern Plant (Dryopteris)
(vi) There is a prominent circular band
known as clitellum. Which covers three
segments viz 14th, 15th and 16th.
(vii) Each segment has a ring of chitinous setae
for locomotion.
(viii) A single female genital aperture is present
ventrally in the 14th segment, and paired
male genital apertures are present on the
ventral surface of the 18th segment. In the
17th and 19th segments, the genital or
copulatory papillae are located.
(ix)
It is a hermaphrodite animal. Cocoons are
produced by sexual reproduction, from
which minute young earthworms hatch out.
(x)
It has immense economic value, It makes
soil fertile and therefore it is also known
as “Farmer’s friend.”
8. PRAWN (PALAEMON)
Identification and Classification:
It is found in rivers and ponds. Its body is curved
in the abdominal region. The cephalothorax is
covered by an exoskeleton, called carapace. They
CORE EXPERIMENTS
23
are jointed legged animals.
with 8 segments of thorax) and a large
laterally compressed abdomen (6
segments).
Kingdom- Animalia (Multicellular, heterophic).
Phylum - Arthropoda (Jointed legs, chitinous
ex-oskeleton)
Class
- Crustacea (5 pairs of walking legs,
body divided into cephalothorax
and abdomen.)
Genus - Palaemon.
Comments:
(i)
(vi)
The thorax has got eight pairs of
appendages, out of these five pairs are
walking legs. The appendage of
abdomen are used for swimming.
(vii) They exhibit sexual dimorphism i.e.,
males and females can be identified by
some external features.
The second pair of legs in males are
comparatively longer and more powerful
then in females. During breeding season
egg mass can be seen on ventral side of
females at the base of legs. The base of
the third pair of legs in females have
female reproductive pores. The males
have male reproductive openings on the
base of the 5th pair of legs.
It is found in ponds, waterfalls, water pools,
rivers and lakes. It is nocturnal in nature,
(viii) In the lakes they are reared for
commercial production.
Fig. 5.7 Palaemon
during the day time it hides in the deeper
layers of the lake.
(ii)
(iii)
It is omnivorus. It feeds on microorganisms,
algae and decaying matter present in the
water.
It is a long and cylindrical, curved at the
abdomen and is coma shaped, it is
compressed on the lateral sides.
(iv) The body is divided into cephalothorax
and abdomen. The cephalothorax is
covered by a chitinous exoskeleton
called carapace. 7 pairs of the gills can
be seen by lifting the carapace.
(v)
The head bears two pairs of antennae, a
pair of compound eyes and other
appendages. Its body is divided into a
cephalothorax (5 segments of head fused
CRAB
Identification and Classification:
This is a well known amphibious animal
which can live in and out of water for a long
period. It is characters are just like prawn.
Kingdom - Animalia (Multicellular,
heterotrophic).
Phylum - Arthropoda (Jointed legs,
chitinous covering)
Class
- Crustacea (5 pairs of walking
legs, Body divided into
cephalothorax and abdomen)
Genus
- Carcinus (Crab)
Comments:
(i)
It is well known crustacian arthropod. It
can live in the water and outside without
any difficulty. The various species can
survive in the fresh and marine water.
24
PRACTICAL BIOLOGY - XI
Order
three pairs of walking legs and
body divided into head, thorax
and abdomen)
- Lepidoptera
Genus
- Bombyx
Species
-
mori
Comments:
(i)
Fig. 5.8 Crab
(ii)
The body is dorsoventrally compressed and
circular.
(iii)
The body is divided into cephalothorax &
abdomen. The abdomen is reduced and is
visible only from the ventral surface. The
cephalothorax is broader than longer. Its
locomotion is by 5 pairs of thoracic jointed
legs which are clawed.
(iv)
Antennae are small. It has a pair of
compound eyes near the antennae.
(v)
The male abdominal part
comparatively narrow than female.
Fig. 5.9 Silkworm
is
(vi) There are less appendages in the
abdominal region. In the male 2 pairs and
in female 4 pairs of appendages are
present.
is reared in most of the silk producing
centres is scientifically known as
Bombyx mori.
(ii)
(vii) For non vegetarians it is the food of
choice.
9. SILKMOTH
Identification and Classification:
It is a medium sized cream coloured insect
known as silkmoth.
Kingdom - Animalia (Multicellular,
heterotrophic)
Phylum
- Anthropoda
(Jointed
appendages,
chitinous
covering)
Class
- Insecta (Two pairs of wings,
It is a medium sized insect, found on
mulberry shrubs. The silkworm which
The larvae of this work develops into
pupa by wrapping itself in the silk thread
which are called cocoons. The silk is
obtained from cocoons and that is why
these are known as silk worms.
(iii) The body is divided into head, thorax and
abdomen. The body and the wings are
covered with minute scales.
(iv) Head bears a pair of compound eyes and
a pair of short and the thick antennae.
The siphoning type of mouth parts are
present for sucking liquid nectar.
(v)
The thorax is divided into three
segments. The second & third segment
of thorax bear two pairs of dull coloured
wings. Three pairs of legs are present - one
pair in each thoracic segment.
CORE EXPERIMENTS
(vi)
The life cycle shows eggs, larva, pupa and
adult stages. The adult female lays eggs on
the mulberry leaves and grows. After the
full growth, the larvae stops eating the leaves
and start secreting a sticky substance from
its salivary glands. This sticky substance
becomes silk when comes in contact with
air. The larvae develop into pupae under
the cover of this silk thread around it. After
sometime the developing small worm
breaks the cocoon and young moth hatches
out. After 3-4 days it becomes adult and
female starts laying the eggs.
(vii) The silkworms are reared at silk centres to
get silk and before the insect gets out of the
cocoon, the silk thread is separated and
reeled. In this way this insect is of immense
economical value. About 1000 to 1500
metres of silk thread can be obtained from
a single cocoon.
10. HONEY BEE
Identification and Classification:
It is slightly bigger than the housefly and is a social
insect. They form a bee hive and live in it and are
easily recognised.
Kingdom - Animalia (Multicellular,
heterotrophic).
Phylum - Anthropoda
(Jointed
appendages,
chitinous
covering)
Class
- Insecta (Two pairs of wings,
three pairs of walking
appendages and body divided
into head, thorax and
abdomen).
Genus
- Apis
Species
- indica
Comments:
(i)
The Indian species is scientifically known
25
as Apis indica. The larger variety is known
(A) Worker
(B) Queen
(C) Male
Fig. 2.25 Honeybee
as Apis dorsata, the smaller variety is
known as Apis florae.
(ii)
It is a social insect. They form hives and
live in it. It is a colonial animal and the
colony consists of queen, drones (males)
and workers.
(iii) The work is distributed among the
members of the hives. The queen bee is
largest of all and its work is only to lay
eggs. The worker bees are sterile females
and they make the hives and keep it neat
and clean. The males are less in number.
Their work is to copulagte with fertile
female bees.
(iv) The body character is just like another
insects. It has 2 pairs of wings, three
pairs, of legs, a pair of compound eyes
and a pair of antennae.
(v)
The worker bee have pollen basket on
hind legs and pollen brush is present on
fore legs for collection of pollen grains.
Wax glands are present for the
manufacture of wax. The mouth parts are
suitable to suck nectar from flowers and
give shape to wax.
(vi) Honey and wax are two main important
substances obtained from honeybee.
These are economically very valuable.
(vii) Honeybee rearing centres - the apiaries
are established to obtain honey and wax
commercially.
26
PRACTICAL BIOLOGY - XI
bears two pairs of tentacles. The posterior
pair bears a pair of eyes.
11. SNAIL
Identification and Classification:
Slow moving soft bodies snail is usually found in
the gardens and lawns. It is classified as under Kingdom - Animalia (Multicellular,
heterotrophic).
Phylum - Mollusca (Soft bodied, shelled)
Class
- Gastropoda (spirally coiled
shell or without a shell)
Genus
- Helix and Pila
(iii)
(iv) On the ventral surface of the head mouth
is present. On the right side of the shell
an opening is present which is used for
breathing.
(v)
Comments:
(i)
Helix can be seen creeping slowely in the
gardens, lawns and moist earth. Other than
this snails found on the earth, snails are also
Fig. 2.26
It is herbivorous. It feeds on leaves, buds,
fruits and destroys plants.
They are hermaphrodite. In the rainy
season they lay eggs and cover them.
Young snails come out of the eggs in
about a month.
(vi) In the foreign countries some species are
also used as food.
PILA
(i)
It is found in ponds, rice fields, lakes,
rivers and swamp places. Is nocturnal in
habit.
(ii)
It is herbivorous. It eats the vegetation
with great speed.
(iii) The whole body lies in the shell. 6-1/2
coils are present in the shell. On the base
there is an operculum by which the base
can be closed.
(iv) According to the need when it opens the
operculum head, eyes and tentacles can
be seen.
Fig. 2.27
Fig. 2.26 Helix
Fig. 2.27 Pila
found in the ponds, rivers, swamps, and rice
fields. Pila is a very commonly found snail.
Helix
(i)
(ii)
Helix are nocturnal and while creeping
secrete a sticky chemical. This chemical
facilitates in locomation.
About 4 cms in size this soft organism has
a coiled shell on the dorsal surface. The
head protrudes from anterior part which
12. STARFISH
Identification and Classification:
This star shaped marine organism is actually
not a fish. They can be observed lying in sand
on sea shore or swimming in water with its
five radiating arms.
Kingdom - Animalia (Multicellular,
heterotrophic).
Phylum - Echinodermata (Radially
symmetrical, spines on skin)
CORE EXPERIMENTS
Class
- Asteroidea (Star shaped)
Genus
- Asterias
Comments:
(i)
27
helps in feeding, circulation and movement.
(ix)
It has a great power of regeneration.
(x)
The male and female individuals are
separate. They reproduce sexually. The
larval stage shows bilateral symmetry.
It is a marine animal crawling on sandy
shores under big stones embedded in the
muddy water.
13. SHARK
Identification and Classification:
Shark fishes are found only in sea. They are of
many shapes and sizes. Placoid scales are
present all over the body. This shark is known
as dogfish.
Fig. 2.28
(ii)
Starfish (A) Aboral view (B) Oral view
It is carnivorous and eats crustaceans,
mollusc and microorganisms.
(iii) It’s body is compressed on the oro-aboral
axis.
(iv) There is a central disc from which five
arms arise. Ventral surface of the disc is
oral surface having mouth and the dorsal
surface is known as aboral surface
bearing anus.
(v)
Kingdom - Animalia (Multicellular,
heterotrophic).
Phylum - Chordata (Notochord during
embryonic stage, Pharyngeal
gill slits and dorsal tubular
nervous system)
Class
- Chondrichthyes (Cartilagenous
fish, open gills)
Genus
- Scoliodon
Comments:
(i)
This shark is popularly called as ‘Dog fish’
and is widely distributed.
(ii)
The body is spindle shaped and laterally
Oral surface is kept towards the sea
bottom and the aboral surface is away
from it. On the ventral surface
ambulaeral grooves are present in each
arm containing tube feet for locomotion.
(vi) The locomotion is by tube feet.
(vii) The disc is slightly elevated at the aboral
surface. On this surface spines and
forceps shaped pedicillariae are present.
The anus opening is slightly away from
the disc centre.
(viii) A distinct area called madreporite is present
on the aboral surface leading to water
vascular system of the animal. This system
Fig. 2.29 Dogfish — A Shark
compressed on both the ends. The head is
dorsoventrally compressed. Semicircular
mouth opening is present on ventral surface.
Sharp teeth are present in the mouth.
28
PRACTICAL BIOLOGY - XI
(iii)
Placoid scales are present all over the body.
Lateral line acts as a sense organ.
(iv)
On the lateral sides of the body, there are 5
pairs of gill slits. These are respiratory
organs.
(v)
The body has paired and unpaired fins. The
shark has two dorsal, two ventral, two
pectoral, two pelvic and a caudal fin.
(vi)
Entire endoskeleton is made up of cartilage.
Therefore dogfish has been kept in
cartilaginous group of fishes.
(vii) Cloacal aperture is present in between
pelvic fins. On the inner surface of these
pelvic fins claspers are present in the
males for copulation.
(viii) The female fish gives birth to young ones
and thus it is a viviparons fish.
14. ROHU
Identification and Classification:
It is a fresh water fish found in rivers and ponds.
The body is covered with scales.
Kingdom - Animalia (Multicellular,
heterotrophic).
Phylum
- Chordata (Notochord in
embryonic
stage
and
pharyngeal gill slits and tubular
nervous system are present)
Genus
- Labeo
Species
- rohita
Comments:
(i)
It is commonly found in the rivers, lakes,
ponds of Northern India. It attains a length
of 3-4 feet.
(ii)
It is a carnivorous fish which feeds on
smaller fishes.
(iii) the colour of the fish is greenish black.
The scales are raddish in colour and that
Fig. 2..30 Rohu
is why it is known as Rohu.
(iv)
The head is slightly elevated and is
compressed above eye. Two small
barbels are present just above mouth on
upper jaw. The gills are covered by
operculum on both the sides from the
hinder end of opercula.
(vi) Like other fishes, these also have paired
pelvic and pectoral fins. Besides these,
one dorsal, one anal and a caudal fin is
also present.
(vii) They breed in rainy season. Female lays
eggs which are settled at the bottom.
Male fish drops sperms on these eggs.
This is known as external fertilization.
(viii) This fish has a great economic value.
15. FROG
Identification and Classification:
This is a well known amphibious animal which is
found near the ponds & lakes. They jump into the
water when ever they hear some noise or feel some
danger.
Kingdom - Animalia (Multicellular,
heterotrophic).
Phylum - Chordata (Notochord and
pharyngeal gill slits persent
only during embryonic stage
and dorsal tubular nervous
CORE EXPERIMENTS
Class
Genus
Species
system present throughout life)
- Amphibia (Skin moist,
amphibian.)
- Rana
- tigrina
Comments:
(i)
Found in or around lakes and ponds.
(ii)
The skin is smooth and is covered by
mucous.
29
(viii) The trunk region comprises of two pairs of
limbs - fore limbs and hind limbs.
(ix)
The hind limb is much larger and consists
of foot and toes. A membranous foot web
is present in between the toes.
(x)
During breeding season the male frog can
easily be recognised by its shining colour
and while making sound (croaking) enlarged
vocal sacs can be seen easily.
(xi)
A cloacal aperture is present towards the
posterior end of the body.
(xii) They breed during rainy season. The
female lays eggs in a cluster in the water
and male release the sperms over them.
Hence external fertilization takes place.
16. TOAD
Cloacal
aperture
Identification and Classification:
Fig. 2.32 Frog
(iii)
The dorsal surface has greenish colour and
the ventral surface has yellowish coloured
skin.
(iv)
The body is boat shaped suitable for
swimming.
(v)
The body is divided into head and thorax.
There is no neck and tail.
(vi) On the top of the head there are two
bulging eyes. The head is pointed in front
and is broad at the back. On the pointed
snout there are two external nares and
behind the eyes are tympanic
membranes. In between the eyes is a
brow spot. On opening of the mouth
teeth can be seen in the upper jaw. The
tongue is bifurcated at the anterior end.
(vii) On the dorsal surface in the centre is a dorsal
line. When the frog sits on the ground a
hump can be seen.
The toads are usually seen at night in the house
courtyard or under the lamppost. The mouth is
less pointed as compared to the frog.
Kingdom - Animalia
(Multicellular,
heterotrophic).
Phylum
- Chordata (Notochord and
pharyngeal gill slits present during
embryonic development. Dorsal
tubular nerve cord throughout life)
Class
- Amphibia (amphibian, wet skin.)
Genus
- Bufo
Species
- melanostictus
Comments:
(i)
The toad which resembles frog in many
30
PRACTICAL BIOLOGY - XI
Phylum
Class
Genus
heterotrophic).
- Chordata (Notochord and
pharyngeal gill slits present
during embryonic development.
and dorsal tubular nerve chord
throughout life)
- Reptilia (skin dry and covered
with horny scales, creepers)
- Calotes.
Fig. 2.33 Toad
Comments:
respect is found on the earth in moist
places and never in water.
(ii)
They are nocturnal. They are not timid
but are fearless.
(iii)
The lower jaw is not triangular but is
semilunar in shape.
(iv)
The skin is dry and bulging in places.
It has less mucous glands and more
poison glands.
(v)
Eyes, nostrils, brow spot, tympanic
membrane etc. are present similar
to frog. But it has no teeth and the
tongue is not bifurcated.
(vi)
The hind limbs are larger than the forelimbs
but comparatively smaller than the frog. It
has no foot web in the toes.
Fig. 2.34 Calotes
(i)
Calotes is about 1 foot long, very active
animal and found in bushes and on trees.
(ii)
It changes its colour just according to the
place where is lives. The neck is reddish in
colour and that is why it is also known as
blood sucker.
(iii)
It’s skin is dry and is covered by scales.
(iv)
The body is divided into head, short neck,
trunk and tail. The tail is long and cannot
be regenerated.
(v)
The small head is pointed anteriorly. The
head bears two nostrils and two eyes.
Two external ear openings can be
observed behind the eyes.
(vii) There are no vocal sacs in the male.
16. LIZARD
a. The garden Lizard - Calotes
Identification and Classification:
A little bigger than house lizards, this greenish
brown lizard is a familiar animal. It’s colour
changes in different seasons. At the same time
it can change its colour according to the colour
of the wall or tree. That is why it is also known
as ‘girgit’.
Kingdom - Animalia
(Multicellular,
(vi) The trunk is long and narrow. A pair of
fore limbs are present anteriorly and a
pair of hind limbs are present posteriorly.
CORE EXPERIMENTS
31
The hind limbs are slightly bigger than
the fore limbs. Both have five clawed
digits. The scales of trunk region bulge
out like spines.
6.
Claws present on forelimbs.
7.
It runs swiftly on walls and roofs.
8.
Male lizard has femoral pores on the thighs.
(vii) During breeding season and to frighten
the enemy, the side of the head becomes
red and the head turns yellow. Males are
bigger in comparision to females. The
colour of male is brighter than the female
during the breeding season. The female
lays shelled eggs.
9.
It is not posionous as generally thought by
man.
10.
It is helpful to man as it feeds on insects
and gets rid of them.
17. A BIRD
(a) House Sparrow
(b) Wall Lizard
Comments :
1.
Common house lizard found in old houses
and dirty places.
2.
It is nocturnal and feeds on insects near the
light at night.
3.
It is black, brown or grey coloured.
Sometimes dark spots may be present.
It is capable of changing body colour.
4.
Body divided into head, trunk, and tail.
A short neck in present between head
and trunk.
5.
Head is large and triangular.
The house sparrow is a well known small bird.
They live in the houses and verandah.
Kingdom - Animalia (Multicellular,
heterotrophic).
Phylum - Chordata (Notochord and
pharyngeal gill slits seen during
embryonic development and
life long dorsal tubular nervous
system present)
Class
- Aves (feathers on skin,
toothless break, flying animals)
Genus
- Passer
Species
- domesticus
Comments:
Head
Tympanum
Identification and Classification:
external
eares
eyes
claws
Forelimbs
Trunk
Tail
Hind
Limbs
Fig. 2.35 Wall Lizard (Hamidactylus)
Fig. 2.36 House Sparrow
32
(i)
(ii)
PRACTICAL BIOLOGY - XI
This is a small (about 4-5 inch long) bird
which lives in the houses with human
beings. It feeds on grains and insects.
Genus
beak, flying animals)
- Columba
Its dorsal surface is slaty coloured brown
with black stripes are present and the
ventral surface is white in colour.
(iii) The neck and thorax of the male have a
black area.
(iv) The body is divided into head, neck,
trunk and tail. It is boat shapped. The
anterior portion of the head has one beak
without teeth. Thorax has two wings
anteriorly and 2 limbs posteriorly. The
tail is small but the feathers are large.
The whole skin of the body is covered
with feathers. The body is stream-lined
and light due to the presence of air
cavities in the bones.
(v)
Hind limbs have four digits provided
with claws. Three digits are directed
forwards and the fourth one is
backwards.
Wing
feather
Fig. 2.37 Pigeon
Species
Comments:
(i)
Pigeon is simple in nature. It is easily
domesticated. The pigeon found in the
old and large buildings is known as Blue
rock pigeon. They usually live in groups.
They are active in the day time and feed
on grains. At night they rest on the
ventilations, holes in the walls, deep
wells and on hanging things.
(ii)
Pigeons are usually grey coloured. A
shining band of green feathers is present
on the neck, below which voilet colour
is observed. Other than this combination,
many other coloured pigeons are also
seen.
(vi) They make nests in the walls with straw
etc. During breeding season the colour
of male becomes bright yellowish.
(b) Pigeon
Identification and Classification:
Like house sparrow this is also a well known bird.
Pigeon lives in large Ware houses or palaces. It’s
classification is also like house sparrow.
Kingdom - Animalia (Multicellular,
heterotrophic nutrution).
Phylum
Class
- Chordata (Notochord and
pharyngeal gill slits seen during
embryonic development and life
long dorsal tubular nervous
system present)
- Aves (feathers on skin, toothless
- livia
(iii) Like other birds, the skin of the pigeon
has feathers, a toothless beak, a pair of
wings, a pair of limbs and a tail. The
body is narrow anteriorly and posteriorly
but is broad at the centre.
(iv) It forms nest of grass, straw etc. The
female lays round white eggs twice a
year. The nest is made on the ventilators
of houses, wells or gaps in walls.
(v)
Pigeons can be trained. The domesticated
CORE EXPERIMENTS
33
pigeon when made to fly comes back to
the master’s house.
18. A Mammal
(a) Rabbit
nature. They run with high speed (30-40
kmph).
(iii)
They are about 1-1/2 feet long, the skin is
covered thickly with hairs (fur). Hairs are
muddy white in colour. Domestic rabbits
are of many colours.
(iv)
The body is divided into head, neck, trunk
and tail. Trunk is further divided into thorax
and abdomen.
(v)
Snouted head is large. In between upper
lip and nostrils hair like vibrissae are
present. The upper lip has a gap and the
teeth can be seen from this gap. These
teeth are called incisors. On the head a
pair of eyes and a pair of long ears are
present which can be moved to any
direction.
Identification and Classification:
Rabbit is medium sized very beautiful mammal.
They live in the open fields by making burrows
and tunnels. It can be domesticated also.
Classification is as follows:
Kingdom - Animalia (Multicellular,
heterotrophic).
Phylum
- Chordata (Notochord and
pharyngeal gill slits present in
the embryonic stage. Dorsal
tubular nervous system
present.)
Class
- Mamalia (Skin with hairs.
Presence of external ears and
mammary glands)
(vi) Neck is small.
(vii) Between the thorax and abdomen 4-5
pairs of mammary glands are present on
ventral surface. The nipples of glands are
better developed in females. Young
rabbits suck milk from these gland.
(viii) The tail and anus is situated on
the posterior end of the abdomen.
Below the anus scrotal sacs and penis
are present in the male. The female has
a vulva below the anus.
(ix) Hind limbs and fore limbs are
present in the trunk. The fore limb has
5 clawed digits and the hind limb has
4 digits with claws. The palm and the soles
have pads. The forelimbs are used for
digging.
Fig. 2.38 Rabbit
Genus
- Oryctolagus.
Species
- cuniculus
Comments:
(i)
Rabbit is simple in nature and beautiful
animal. They live in grassy grounds and
live in hole or tunnels in a group.
(ii)
Rabbit is herbivorous and nocturnal in
(x)
Rabbits are economically important
animals. Many articles are made out of its
skin and the flesh is eaten. They destroy
the crops.
(b) House Rat
34
PRACTICAL BIOLOGY - XI
Classification:
Classification:
Phylum
- Chordata (Notochord present in
some stage of life.)
Phylum
- Chordata (Notochord present in
some stage of life.)
Class
- Mammalia (Body hair present
mammary glands present)
Class
- Mammalia (skin covered with
hair with mammary gland)
Order
- Rodentia (upper incisors - 1
pair well developed)
Order
- Insectivora (Insectivorous)
Genus
- Corcidura
Genus
- Rattus
Comments:
Comments:
1.
Found in homes and food granaries.
head
external
eye ear
neck
external
ear
Trunk
head
Trunk
hair
eye
nostrits
Tail
snoul
vibriosae Forelimb
Hindlimb
claws
Tail
Hind
limb
Fig. 2.39 Rattus
Forelimb
Fig. 2.40 Corcidura
1.
It lives in burrows inside homes.
2.
It is nocturnal and carnivorous. Feeds on
small insects.
2.
Body covered with brown hair.
3.
Long hairy whiskers present called
vibrissae.
3.
Body is approximately 15 c.m long and
brown in colour.
4.
On the ventral surface of chest mammary
glands present which are developed in
the females.
4.
Snout is long and pointed.
5.
Eyes are very small and external ears not
clearly visible.
5.
Different types of teeth present. In total
16 teeth are present.
6.
6.
Claws present on digits of both forelimbs
and hind limbs.
Forelimbs and hind limbs are small.
Each of them have 5 digits with claws.
They help in making burrows.
7.
Tail is long.
7.
It is man’s enemy as it destroys food
grains and spreads diseases like plague.
8.
Teeth sharp and pointed.
9.
Being insectivorous it destroys harmful
household insects, thus useful to man.
(c) Mole