Introduction to Biology

Biology

Biology is the branch of science which deals with the study of living organisms. The terms Biology is derived from two Greek words "Bios" means life and "Logos" means knowledge. Thus biology is science of life. It is an organized study of living things and of the theories that men have devised to describe and explain the world of life.

Branches of Biology

Branches of Biology

1. BOTANY The branch of biology which deals with the study of plants.
2. ZOOLOGY The branch of biology which deals with the study of animals. Some of the important branches of biology common to botany and zoology are:
a. MORPHOLOGY It deals with the study of external structures of animals and plants.
b. HISTOLOGY It deals with the study of tissues of plants and animals under microscope.
c. CYTOLOGY It is the study of the cell and its organ.
d. PHYSIOLOGY It is the study of working of various systems of living organisms.
e. ECOLOGY It is the study of relationship of living organisms with their environment.
f. TAXONOMY The branch which deals with classification and naming of living organisms.
g. GENETICS It deals with the study of inheritance of character from one generation to another.
h. MICROBIOLOGY It deals with the study of microscopic organisms such as virus, bacteria and protozoans.
i. BIOTECHNOLOGY It deals with the application of biological processes for the benefit of mankind.

Biological Methods

Biological Methods

Although biology is a distinct branch of science, its method is similar to that of its other branches. Following are the steps involved in investigation of biological phenomenon.
IDENTIFICATION OF PROBLEM At first problem should be identified.
COLLECTION OF THE DATA ON THE BASIS OF OBSERVATION Fact are collected related to specific problem. HYPOTHESIS It is scientific guess on the basis of observation. It needs experimental verification.
EXPERIMENTATION The proposed hypothesis is examined by experiments designed especially for this purpose. THEORY If hypothesis is verified by experiments it is given a status of theory.

Malaria

Malaria

Malaria has been a big problem for man for centuries.
SYMPTOMS OF MALARIA Shivering due to chill followed by very high fever. The patient sweats his breath and respiratory rate increases.
THE HISTORY OF MALARIA Malaria was one among many other diseases for which cure was needed. Although no cure was found for malaria by Greeks, when Romans took over from them, they made a simple observation. Malaria was common among people living near marshes. In fact the word malaria is of Roman origin, "Mala" means bad and "aria" means air. The Romans thought that the bad air of the marshes was poisonous and caused malaria.
In 1878, a French physician Luhveran discovered Plasmodium in the sample of blood of patient suffering from malaria. It was soon found that plasmodium is present in the saliva of female Anopheles mosquito. When it bites a human it transfers plasmodium into his blood and cause malaria.
Female anopheles ¾ ¾ ® Human being ¾ ¾ ® Malaria The human efforts in the field of medicinal plants led to the discovery of Quinine from cinchona plant. Now a days it is easily careable disease.

Muslim Biologists

Muslim Biologists

ABDUL MALIK ASMAI:
He was born in Busra in 741 AD he was regarded as specialist of this time in animal science.
PUBLICATION
He wrote many books on animals and plants. Following are the names of his famous books:
Al - Kheil:About horses 
Al - Ibit:About camels 
As - Shat:About sheep 
Al - Wahoosh:About wild animals 
Khalaqul Insan:About different parts of human body

ALI BIN RABBAN TUBRI:
He was born in 775 A.D in Tubristan and died in 870 AD.
PUBLICATION
FIRDUS - UL - HIKMA
The book has many illustrations and detailed articles on objects like philosophy, zoology, psychology and astronomy.
AL - FARABI
(870 - 950 AD)
He was renowned Hakim of Islamic world.
PUBLICATION
He wrote two well known books.
Kitab - i - Nabatiat 
Kitab - ul - Haywanat 
ABUL QASIM AL - ZAHRAVI
(936 - 1004 AD)
He was renowned surgeon of the Islamic world. He was famous for the removal of stone from the urinary bladder.
IBN - AL - HAITHAM (965 - 1039 AD)
He is one of the most outstanding figures of Muslim history, being an optician of great merit and stature. Some 200
scientific works said to have been written by him on diverse subject. He was the first on to correct the Greek conception of 
vision, locating retina as the seat of vision.
PUBLICATION
Kitabul Manazir 
Mizanul Hikma 
BU - ALI - SINA
He was born in Kharmsheen near Bukhara in 10th century AD. He was considered to be one of the founders of medicine. 
Aside from medicine he was expert in mathematics, astronomy, physics, paleontology and music.
ZIA - UD - DIN IBN BAITAR
Zia-ud-din Ibn Baitar of 13th century specialized in the study of plants. He was highly respected among the scientists of 
the middle age.
IBN - AL - NAFEES
He described the blood circulation during 13th century.
KAMAL - UD - DIN AL DAMIRI
He was the greatest zoologist of his time. He compiled a book "Hayat-al-Haywan" during the 14th century which was about
thousand kinds of animals.
ALI BIN ISA
He was a well known eye specialist of his times and worked on structure, function and diseases of eye. He wrote three
volumes on this subjects in which he has described 130 diseases of the eye.
ABUL QASIM MAJREETI
He is especially known in Europe for his book on animal species.
AL - JAHIZ
He wrote a famous book "Al-Haywan". In this book he described his own observations on animals.
MUSLIM BIOLOGISTS	
(i) Name: Abdul Malik Asmai 
Period: 741 AD 
Publication: Al-Khail 
Al-Ibit As-shat Al-Wahoosh Khalaqul Insan
Topic: 
Horses Camels 
Sheep Wild animals Human body.

(ii) Name: Ali Bin Rabban Tubri 
Period:775 - 870 AD 
Publication: Firdus-ul-Hikma	
Topic: Philosophy,Zoology Psychology astronomy 

(iii) Name: Al-Farabi	
Period: 870 - 950 AD 
Publication: Kitab-ul-Haywanat Kitab-ul-Nabatiat 
Topic: Animals,Plants

(iv) Name: Abul Qasim Al Zahravi 
Period: 936 - 1004 AD 

(v) Name: Ibn-al-Haitham	
Period: 965 - 1039 AD 
Publication: Kitab-ul-Manazir, Mizan-ul-Hikma 
Topic: Eye	


(vi) Name: Bu-Ali-Sina	
Period: 10th century AD 

(vii) Name: Zia-ud-din Ibn Baitar 
Period: 13th century AD 

(viii) Name: Ibn-al-Nafees	
Period: 13th century AD 

(ix) Name: Kamal-ud-din Al-Damiri 
Period: 14th century AD 
Publication:Hayat-ul-Haywan	
Topic: Animals

Quranic Teachings about Animal and Plant Life

Quranic Teachings about Animal and Plant Life

It says about the origin of life that
"We made from water every living thing. Will they not then believe?"
(Sura Anbiyah 21, Ayah 30)
"And Allah has created every animal from water. Of them these are some that creep on their bellies. Some that walk on two 
legs and some that walk on four. Allah creates what he pleases. He has power over all things."
(Sura Nur 24, Ayah 45)
"He sends down water from the sky and with it brings forth the buds of every plant. From these we bring forth green foliage and 
close-growing grain, Palm-trees laden with clusters of dates with in reach, vineyards and olive groves and pomegranates (which are) 
alike and different. Behold their fruits when they bear fruits and ripen surely. In these there are sign for true believers."
(Sura Anam 6, Ayah 99)
"He has made for you the earth like a carpet spread out, has enabled you to go about there by roads and channels, and has send 
down water from the sky. With it we have produced diverse pairs of plants each separate from the other."
(Sura Ta-Ha 20, Ayah 53)
"And in the earth are tracts and diverse though neighboring, garden of vines and fields sown some with corn and palm trees - 
growing out of simple roots or otherwise. Watered within the same water. Yet some of them we make more excellent than others 
to eat."
(Sura Al Ra’d 13, Ayah 4)
"It is Allah who splits the seeds and the fruit stone. He brings forth the living from the dead, and the dead from the living. How then 
can you turn away from him."
(Sura Anam, Ayah 95)
"And virly in cattle too ye find an instructive sign. From what is with in their bodies, between excretion and blood, we produce for 
you drink milk pure and *** to those who drink it."
(Sura Nahal 16, Ayah 66)
"We have spread out the earth and set up on it immovable mountains. We have caused to grow in it from every ordained things."
(Sura Hajar 15, Ayah 19)
"Glory be to him who created pairs of all things which the earth grown and of their own kind and that of which they have no 
knowledge."
(Sura Yasin 36, Ayah 36)
"And your Lord taught the bee to build its cells in hills, on trees and in men’s habitations.
"Then to eat of all the produce (of earth) and find with skills the spacious path of its Lord, their issue from within their bodies a 
drink of varying colours, wherein is healing for men. Varily in this is a sign for those who give thought."
(Sura Nahal 16, Ayah 68-89)	

Significance of Biology

Significance of Biology

Biology helps us to understand our lives and the world we live in, it has made an enormous impact on human welfare. 
Following are the points on importance of biology.
An ever increasing human population require more and more food. Food production can be increased by careful study 
of plants and soil and improved techniques in animal husbandry. 
Biology has enabled man to realize the importance of balanced diet. Biological studies have also helped to control pest. 
It is through advancement in biology that man has able to control diseases with the consequence that mortality rate 
has decreased and individuals live longer and lead healthy lives. 
In the field of health the discovery of antibiotics and vaccines is note worthy. These remedies have been revolutionary 
in controlling epidemic diseases.

Fill in the Blanks

Fill in the Blanks

Biology is the study of living organisms.	 
The word biology is combination of two Latin words Bios and Logos.
The word malaria is of Roman origin Mala means bad and aira means  Air
Antony van Leenwenhock in Holland invented first microscope in 1960
Bacteria was discovered in  1776
Luhveran  Plasmodium  was discovered by French physician in 1878.
Anopheles Plasmodium is transmitted to man by female,mosquito.
Cinchona Malaria is treated by Quinine obtained from plant.
Malaria is caused by a protozoan Plasmodium	
Botany is the branch of biology which deals with the study of Plants	
Zoology is the branch of biology deals with the study of  Animals	
Morphology deals with the study of external structures of living organisms.
Histology deals with the study of tissues.
Cytology	deals with the study of cells.	
Physiology deals with the study of working of different systems of living organisms.
Ecology deals with the study of relationship of living organisms with their environment.
Taxonomy deals with the naming and classification of living organisms.
Genetics deals with the inheritance of characters from one generation to another.
Microbiology	is the study of microscopic organisms.
Biotechnology deals with the application of biological processes.
Ali bin Isa was a well known eye specialist of his time.
The famous book Al-Haywan was written by Al - Jahiz	.
The single major contribution of Muslim scientists in the field of scientific methods is use of Experiments
The two main subdivision of biology are and each of which has several further branches	Zoology, Botany

Cell Metabolism

Cell Metabolism

The chemical reactions that takes place in cells. The molecules taking part in these reactions are called metabolites. Some metabolites are synthesized with in the organism, while other have to be taken as food. Metabolic reactions occurs in small steps, comprising a metabolic pathway. Metabolic reactions involve the breaking down of molecules to provide energy are catabolism, and the building up of more complex molecules and structure from simpler molecules are anabolism.

Plant Kingdom

Plant Kingdom

Plants are organisms which have chlorophyll and cell wall besides other characteristics. Plants are classified as flowering and non-flowering plants.

Non-flowering plants are classified into Bryophytes and Pteredophytes while flowering plants are classified into Gymnosperms and angiosperms.

BRYOPHYTES
They lack vascular tissue and are mostly found on rocks, walls, trees in wet and shady places.
Mosses and liverworts are representative members of bryophytes.
Their root like structure are known as rhizods.
Mosses play an important role in disintegration of rocks.
They are often used as manure.
They reproduce sexually as well as asexually.

MOSSES AS AN EXAMPLE OF BRYOPHYTES
Mosses are small plants more advanced than algae.
They do not possess true root, stems and leaves.
Their stem is usually unbranched and has very small green leaves spirally arranged on it. There is no mid rib in the leaf.
They are fixed to the soil by rhizoids.
Mosses are aquatic plants but grow in cool, moist and shady places on land.
They often form mats on the floor of the forest.

PTRIDOPHYTES
They are lower vascular plants.
Sporophytes is the main vegetative stage in the life cycle.
They sporophyte bear root, stem and leaves but flower and seeds are absent.

FERN AS AN EXAMPLE OF PTRIDOPHYTES
Ferns possess special tissues for conducting water, salts and food to different parts of their body.
They have well developed roots, stem and leaves.
They lack flower fruit and seeds.
They are antotrophic.
Ferns are adapted to live in cold, humid and shady places.
Some of them live in water while others grow on shady hills or even on dry mountain tops.

GYMNOSPERMS
Plants included in this group produce seeds like ordinary flowering plants.
Their seeds are not enclosed in fruits as in flowering plants, they are called gymnosperms.
Gymnosperms are usually tall woody trees.
These trees live for many years.
They remain green through out the year, they are also known as ever green plants.
These trees are found in colder regions at high altitude.
Their leaves are long and needle like.
Conifers is a subgroup of gymnosperms. Seeds of conifers are present in hard woody scales arranged to form cone. Therefore these plants are called conifers. These trees produce timber, gum, turpentine oil and dry fruits like chilgoza.
Examples of gymnosperms are cedars (deodar), paius (chir), cupressus and jhuja.

ANGIOSPERMS
Seeds of angiosperms are enclosed in fruits.
They bear flower as the organ of reproduction.
The angiosperms are the most diverse and abundant group of plants.
The leaves of angiosperm plants are usually broad and flat.
Flowers may be unisexual or bisexual.
Pollination takes place through wind and insects.
Angiosperms have been divided into two classes on the basis of structure of the seeds. (a) Monocot, (b) Dicot.

(a) DICOTYLEDONOUS PLANTS (DICOTS)
They have two cotyledons in their seeds. e.g., sheesham, almond, peach, apple, pear, plum and mango.

(b) MONOCOTYLEDONOUS PLANTS (MONOCOT)
They have one cotyledon in their seeds. e.g., grass, wheat, rice, maize, sugar cane and bamboo.

Water

Water 
It is essential constituent of cytoplasm, about 70% of most tissues consist of water.

Storage of Food in Plants

Storage of Food in Plants

Plants manufacture excess amount of food and store it in the different parts of the plant body. Examples,

1. ROOT

In turnip, radish, carrot and beet plants excess food is stored in roots.

2. STEM

In potato and ginger food is stored in stem.

3. SEEDS

Food is also stored in seeds of plant which is used by embryo during development.

Stored food is utilized by plants during autumn as leaves fall in autumn and food cannot be prepared by plants.

Food cycle

Food cycle
 
The cyclic flow of chemical elements from non-living environment to living organisms and from living organisms to
 non-living environment. Producers make food by the process of photosynthesis. This food is passed through series of 
consumers to decomposers. Decomposers convert the complex form to their simpler element form.

Germination of Castor seed

Germination of Castor seed

GERMINATION

It is the process of activation of dormant embryo. Germination of castor seed involves following steps.

First moisture is absorbed by caruncle and water enter into the seed through micropyle. When it reach to the tegmen it rupture this covering. Finally it reach to endosperm and embryo. Water bring dissolve oxygen to embryo. Embryo starts to germinate. The radicle produces root and plumule produces shoot.

CONDITIONS NECESSARY FOR GERMINATION

Following are the conditions necessary for the process of germination.

1. Water
2. Suitable temperature
3. Oxygen

a) WATER

Water makes seed soft and bring dissolve oxygen to the embryo.

b) OXYGEN

The germinating seeds receive oxygen for respiration.

c) SUITABLE TEMPERATURE

The process of germination is controlled by number of enzymes which works at specific range of temperature. The best temperature for germination is between 28° C to 37° C.

TYPES OF GERMINATION

1. EPIGEAL GERMINATION

The germination in which cotyledon comes above the surface due rapid growth of hypocotyle. E.g., castor seed germination.

2. HYPOGEAL GERMINATION

The germination in which cotyledons remain under the soil and plumule (shoot) comes above the soil due to rapid growth of epicotyle.

Cell Division

Cell Division

Cells increase in number by division. During this process the nucleus divide first (Karyokinesis) which is followed by the division of cytoplasm (Cytokinesis). There are two main types of Cell divisions.

Mitosis
Meiosis

1. MITOSIS

The division in which the parent cell divide into two daughter cells in a way that the number of chromosomes in the daughter cell remains the same as in the parent cell.

Although mitosis is a continuous process, it can be divided into four stages, which are:

Prophase
Metaphase
Anaphase
Telophase

A. PROPHASE

During early prophase chromosome become visible as thread like structure.
Each chromosome at this stage is already doubled i.e., it contain two chromatids.
The nuclear membrane disappear gradually.
Contrioles move towards opposite poles of the cells and give rise to spindle fibers.

B. METAPHASE
During this phase each chromosome arranges itself on the equator of the spindle.
Each chromosome is attach to separate spindle fiber by its centromare.

C. ANAPHASE
In this process the centromare divide and chromatids of each chromosome separate from each other and began to move towards opposite poles.

D. TELOPHASE
This is a stage when the chromatids (now called chromosomes) reach the poles and their movement ceases.
Nuclear membrane is formed around each set of chromosomes.
Soon the cytoplasm of the cell divides and two daughter cells arise. The nucleus of daughter cell contain the same number of chromosomes as the parent cell.

SIGNIFICANCE OF MITOSIS

It provides a mean for asexual reproduction.
It takes place during the growth.
Damaged cells are replaced by new cells which are formed by mitosis.

2. MEIOSIS
The process of cell division leading to the production of daughter nuclei with half the genetic compliment of the parent cell. Meiosis consist of the two divisions during which the chromosomes replicates only once.

FIRST MEIOTIC DIVISION

Fist meiotic division is divided into following phases.

a) PROPHASE 1
Homologous chromosomes come together and forms pair. In each homologous pair there are four chromatids. Homologous chromosome exchange their parts at certain places. This exchange is called crossing over. The nuclear membrane disappears and spindle fibers are formed.

b) METAPHASE 1
During this phase pairs of homologous chromosomes arrange themselves on the equator of the spindle. Unlike mitosis, it is the homologous pair and not the individual chromosome attach at the separate fibers of the spindle.

c) ANAPHASE 1
The members of the homologous pairs now begin to separate and move towards the opposite poles.

d) TELOPHASE 1
In this phase chromosome come to rest at the poles. The nuclear membrane is formed around each set of chromosomes resulting in formation of two daughter nuclei. The nucleolus reappears. On completion of nuclear division, division of cytoplasm takes place and two cells are formed.

SECOND MEIOTIC DIVISION

Second meiotic division is almost similar to mitosis. During prophase spindle are formed and the nuclear membrane disappears. In metaphase chromosome arrange themselves on the equator. Their chromatids separate from each other in anaphase and migrate to the opposite poles. In Telophase the nuclear membrane reappears around each set of chromatids (now called chromosomes) and cytoplasm divides forming two daughter cells. So at the end of meiosis four daughter cells are produced in total each possessing a haploid nucleus.

Ecology

Ecology

It is the branch of biology which deals with the study of interaction of living organisms with their environment.

Structure of Castor Oil

Structure of Castor Oil

It is oval in shape and brown in colour. It is dicotyledonous seed.

EXTERNAL STRUCTURE

1. CARANCLE

It is knob like outgrowth at one end of seed. It has spongy tissues which absorb water.

2. HILUM

It is small depression near caruncle.

3. MICROPYLE

The small opening on one side of hilum is called micropyle

INTERNAL STRUCTURE

It consist of following parts.

1. Seed coat
2. Endosperm
3. Embryo

i. SEED COAT

Seed coat consist of two layers the outer one is testa while the inner one is tegmen.

ii. ENDOSPERM

Inside the seed coat there is a food reserve in the form of albumen.

iii. EMBRYO

Embryo consist of plumule, radicle and cotyledon.

a) PLUMULE

It develop to form shoot.

b) RADICLE

It develop to form root.

c) COTYLEDONS

There are two cotyledons which come out after germination of seed and for short period of time performs the function of photosynthesis

Animal Kingdom

Animal Kingdom

Animal kingdom is also a very diverse group ranging from simple animal to such complex mammals as humans. This kingdom is divided into two sub kingdoms depending upon presence or absence of backbone. Those which do not possess backbone are called invertebrates and those which have it are called vertebrates.

INVERTEBRATES

The number of invertebrates in nature is far greater than the numbers of vertebrates. Many invertebrates have no skeleton. Some have exoskeleton and few have endoskeleton. Following are the important phylums of invertebrates.

1. PHYLUM PROTOZOA

Protozoans are smallest animals as their body consist of single cell.
They may be free living or parasite.
Some protozoan parasites cause different diseases like malaria, dysentery etc.
Some of them are marine and they secrete calcareous shell around them.
Free living protozoans are amoeba, paramecium and euglena.

2. PHYLUM PORIFERA
Body contains cavity, or system of cavities connected to exterior by pores.
Cavity lined by flagellated cells for creating water current.
Exoskeleton is calcareous, siliceous or horny spicules.
Always sessile.
Little intercellular integration and coordination. Body virtually a colony of single cells.
No sensory or nerve cells.

EXAMPLES
ASCON

Simple sponge with uniform body wall.

SYCON

More complex sponge with folded body wall.

3. PHYLUM COELENTRATA

They have sac like body cavity also serve as gut cavity (entron).
Mostly they are radially symmetrical i.e., section passing through any diameter give two opposite halves.
Body wall contains two layers of cells. (biploblastic).
The outer layer of cells is ectoderm and the inner layer of cells is endoderm separated by non-cellular mesogloea.
They exist in two forms polyp and medusa which in typical coelentrata life cycle, alternate with each other.
Tentacles bear explosive cells (nematobalast).

EXAMPLES
Hydra
Flelia
Physalia
Jelly fish etc.

4. PHYLUM ANNELIDA

Metamenic segmentation is exhibited by more structures and organ systems than in virtually any other phylum.
Externally metamerism shows itself in constrictions between successive segments , hence the name of the phylum.
Segments are separated by sheet like septa.
In most annelids each segment bears bristle like cheatae.
Segmented nephridia for excretion and osmoregulation.
Typically there is trochophore larva during development.
EXAMPLES

Earthworm
Leech
Nasius

5. PHYLUM MOLLUSCA

Ventral side of the body has soft muscular foot.
On the dorsal side there is a visceral hump containing the main digestive organs.
Visceral hump generally protected by shell.
Most molluscs have a rasping tongue like radula for feeding.
Gills for respiration.
Majority have lost all traces of metameric segmentation.
EXAMPLES

Snail
Octopus
Squid

6. PHYLUM PLATYHELMENTHES (FLAT WORMS)

Body is flattened dorsoventrally (hence name of the phylum).
Possess a mouth but no anus.
Gut generally has numerous blindly-ending branches.
Flame cells are for excretion and osmoregulation.
Phylum contain many important parasites.
EXAMPLES

Tape worm
Planaria
Liver flake

7. PHYLUM NEMATODA (ROUND WORMS)

They have narrow body, pointed at both ends.
They are rounded in cross section.
They possess thick elastic cuticle.
The phylum contain many important parasites.
ASCARIS

Large worm up to 20 cm long.

HOOK WORMS

Small but destructive gut parasite.

8. PHYLUM ARTHROPODA

Body is covered by chitinous cuticle, hardened to varying degree.
Jointed appendages are present.
Muscles are attached to cuticle which function as an exoskeleton.
Cuticle shed periodically (moulting, ecalysis) to allow for growth.
Body cavity is blood filled, haenocoel, derived from blastocoel.
Coelom much reduced.
Metameric segmentation as in annelid but segments not separated from each other by septa.
Some groups have compound eyes for vision.
Mosquito
Flies
Spider
Centipede
Millipede

9. PHYLUM ECHINODERMATA

Their skin contain calcareous ossicle and spines.
They are exclusively marine.
Rentaradiate in adult stage, but larva is bilaterally symmetrical.
Mouth generally on lower side.
Move slowly but concerted action of numerous sectorial tube feet.
No proper circulatory system.
EXAMPLE

Star fish
Brittle star
Sea urchin
Sea cucumber

10. PHYLUM VERTEBRATA

Notochord replaced in adult by vertebral column (backbone), brain enclosed in cranium (brain case). Vertebrates have been divided into five major groups.

Fishes
Amphibia
Reptilia
Aves
Mammalia

A. FISHES

These are entirely aquatic animals.
Body is spindle shaped.
Body consist of head, a trunk and tail.
In most cases the body is covered with scales.
They possess fins for swimming.
Respiratory organ are gills.
These animals are cold blooded.
EXAMPLES

Sharks
Rays
Dog fish
Rohu
Trout etc.

B. AMPHIBIANS

They can live both on land and under water.
They have simple sac like lungs.
They have moist skin used as supplementary respiratory surface.
They breed in water.
Fertilization is external.
Aquatic larva (tadpole) undergoes metamorphous into terrestrial adult.
Gills are present in larva and lungs are present in adult.
EXAMPLES

Newts
Salamanders
Frogs
Toads

C. REPTILIA

Mainly terrestrial.
Dry skin with scales.
Respiratory organs are lungs.
Fertilization is internal.
Eggs laid on land enclosed in shell.
Cold blooded animals.
EXAMPLES

Lizards
Snakes
Crocodiles
Alligators
Turtles etc.

D. AVES

Body is covered by feathers.
Forelimbs are wings.
Toothless jaw covered with horny beak.
Warm blooded animals.
Larynx is sound producing organ.
EXAMPLES

Ostrich
Gulls
Kiwi
Pigeon etc.
E. MAMMALS

Body is covered with hairs.
They possess mammary glands.
They are warm blooded animals.
They are divided into three large subgroups.
Egg laying mammals
Pouch mammals
Placental mammals (true mamma

Transportation in Animals

Transportation in Animals

FUNCTIONS OF TRANSPORT SYSTEMFUNCTIONS OF BLOODFollowing are some points in significance of transport system.

1. Transport of O₂.
2. Transport of CO₂.
3. Transport of waste products.
4. Transport of hormones.
5. Transport of nutrients.

Spinal Cord

Spinal Cord

Spinal cord is with vertebral column and continuous with medulla oblongata of brain. Spinal concerned with:

1. Reflex functions of parts below head level.
2. Conduction of sensation received from trunk and limbs to the brain.
3. Receiving messages command from the brain.

Energy Flow in an Ecosystem

Energy Flow in an Ecosystem

The light and heat energy from sun is obtained and transferred to the chemical energy by producers. Producers does not absorb all energy. Part of energy is lost by them. From producers energy is transferred to primary consumers during this transfer part of energy is also lost. In this way this chemical energy is transformed to tertiary consumers and decomposers.

Organization of Cells to form Tissues , Organs & Organ system

Organization of Cells to form Tissues , Organs & Organ system

Unicellular organisms consist of single cell. They are capable of independent existence by making use of their organelles. Such organism represent the unicellular organization of life. Wile some cells have stayed at this level of organization other lives have also developed. In some cases cells have come together to form loose assemblies.

TISSUE
A group of cells specialized for a particular function.

ORGAN
A part of an organism that is made up of a number of tissues specialized to carry out a particular function e.g., lung, stomach etc.

Cell ® Tissue ® Organ ® Organization ® Organism

PLANT TISSUE
In plants there are two basic types of tissues which are as follows:

a) MERISTEMATIC TISSUES
These tissues contain cells have the ability to divide. Meristematic cells are smaller in size with thin walls. Apical meristem are present at the tip of roots and stems, and they are responsible for primary growth. The lateral meristem is responsible for secondary growth.

b) PERMANENT TISSUE
These tissues are formed from meristematic cells. They don’t have ability to divide. Their walls become thick to give them definite shape. Following are the types of permanent tissues.

1. DERMAL TISSUES
The cells of dermal tissues are uniform in shape and size, they form outer layer of root, stem and leaf.

2. GROUND TISSUES
They consist of thin walled parenchymatous cells which are formed from meristematic tissues.

These cells are basically meant for storing food but they also prepare some food.

3. SUPPORTING TISSUES
When cell reach a maximum size their cell wall become thick due to deposition of special material and become dead. The tissue is of various shapes and provide rigidity and support to the plant. Sclerenchyma (thick walled lignified elongated) and collenchyma (living cell with thick outer walls with a few and small intercellular spaces) are examples of supporting tissues.

4. CONDUCTING VASCULAR TISSUES
This tissue consist of elongated cells with thick or thin wall. Xylem and phloem are the examples of conducting tissues.

XYLEM conduct water and mineral salts from roots to leaves.

PHLOEM conducts food from leaves to the different parts of the plant body.

ANIMAL TISSUES
Following are the important animal tissues.

a) EPITHELIAL TISSUES
The cells of this tissue occur in single layer and are present very close together. This tissue forms layer and lines tubular organs of the body.

FUNCTION

Protection
Secretion
Absorption

b) CONNECTIVE TISSUES
These tissues provide support to other tissues and organs and bind them together e.g., fatty tissues, tendons and cartilages are examples of connectives tissues. Blood is also a special type of connective tissue.

c) MUSCULAR TISSUES
This tissue is formed of muscle fiber. Each muscle fiber is elongated cell which has ability to contract and relax.

FUNCTION
This tissue cause movement of body and body parts.

d) NERVOUS TISSUES
This tissue is formed of cells called Neurons. Nerve cells are specialized to conduct message in the form of electric current. Nervous system consist of this tissue.

Egg Laying Mammals

Egg Laying Mammals

These mammals lay eggs like the reptiles but feed their young ones on milk.

EXAMPLES

Duck bill
Spiny ant eater

POUCH MAMMALS

These mammals give birth to underdeveloped babies. Since they are weak, the mother keeps them in a pouch on its belly until they develop fully and become strong.

EXAMPLES

Kangaroo
Opossum
Koala bear

PLACENTAL MAMMALS (TYPICAL MAMMALS)

These mammals, the baby completes its entire development in the body of mother.
After birth the youngs are fed on mother’s milk.
These mammals have been divided into many subgroups.

INSECT – EATING MAMMALS

These mammals come out at night and feed on insects.

EXAMPLES

Hedgehog
Shrews
Moles

EDENTATE MAMMALS

In these mammals the front teeth are absent very small. They have long nails with the help of which they dig earth. They fed on ants with the help of their long tongue.

EXAMPLES

Armadillo
Pangolin

RODENT MAMMALS

These mammals have well developed cutting teeth in the form of long curved front teeth.

EXAMPLES

Rabbit
Squirrel
Rat
Porcupine

FLYING MAMMALS

In these mammals the skin between the front limbs and hind limbs is drawn out to form pair of membranous wings for flying.

EXAMPLE

Bat
MAMMALS WITH HIGHLY DEVELOPED BRAIN

These mammals have highly developed brain. They posses a high degree of intelligence.

EXAMPLES

Monkeys
Chimpanzee
Man

CARNIVOROUS MAMMALS

These mammals eat flesh of other mammals. The tearing teeth (canine) are very strong and curved.

EXAMPLES

Cat
Dog
Lion

HOOFED MAMMALS

These are the mammals which possess hoofs and are herbivorous.

EXAMPLES

Goats
Buffalo
Horse
Cow

TRUNKED MAMMALS

They are the largest mammals living on land. They have large trunk or proboscis.

EXAMPLE

Elephant

FISH LIKE MAMMALS

Theses mammals are not fish and permanently live in water. They never come on land. They are mostly marine and are the large aquatic animals. There forelimbs and hind limbs are modified into oar-like fins for swimming.

EXAMPLES

Dolphin
Whales

Nutrition in Plants

Nutrition in Plants

Modes of nutrition in plants. Plants have been classified into following groups 
according to the mode of nutrition.



AUTOTROPHIC

They can prepare their own food by photosynthesis.



HETEROTROPHIC

They cannot manufacture their own food. They are further classified into following 
groups.



Parasites 

Saprophytes 

Insectivores 

Fill in the Blanks

Fill in the Blanks

Nutrition in Green Plants

Nutrition in Green Plants
It is the process by which green parts of the plant prepare their food from carbon dioxide and water with the help of sunlight.

6 CO2 + 6 H2O à C6H12O6 + 6 O2

ESSENTIAL CONDITIONS AND MATERIALS FOR PHOTOSYNTHESIS

1. LIGHT
Light plays following important effects.
Provides heat energy.
By the addition of photon water molecule is splitted into H+ and OH- which results in release of electrons. This process is called photolysis.

2. CHLOROPHYLL
It is green colour matter which is responsible for trapping the sunlight. When light is absorbed by chlorophyll it break water molecule into H+ and OH- and release electrons.

3. WATER
It is raw material for the process of photosynthesis. The hydrogen of water molecule becomes a part of glucose.

4. TEMPERATURE
Photosynthesis is a biochemical reaction, many enzymes are involved in this process. For the normal activities of the enzymes suitable temperature is needed. The temperature which is ideal for the process of the photosynthesis is optimum temperature. The least temperature below which photosynthesis does not take place is minimum temperature and the highest temperature above which photosynthesis does not take place is maximum temperature.

MECHANISM OF PHOTOSYNTHESIS
The process of photosynthesis can be divided into following stages.
1. LIGHT REACTION
Light is necessary for this stage of photosynthesis. The light which is absorbed by chlorophyll is used to break water molecule into H+ and OH- and emission of electrons. Energy is produced by the movement of electrons which is used in the formation of ATP. The product of light reactions is ATP and NADPH2.

2. DARK REACTION
Light reaction is followed by dark reaction. The products of light reaction are used as a reactant in the dark reaction of the photosynthesis. The first stable product of the dark reaction is glucose, which is then converted into starch and other compounds.

EXPERIMENTS ON PHOTOSYNTHESIS
The first stable product of photosynthesis is glucose which is then converted into starch. Presence of starch shows that the process of photosynthesis has taken place.

STARCH TEST
OBJECT
This test is performed to check the presence of starch. It consist of following steps.

METHOD
Take a green leaf, kill the cells of the leaf by boiling it in water for very small period of time.
Boil the leaf in alcohol using water bath to remove chlorophyll from the leaf.
Wash the leaf with water and place it in a dish containing iodine reagent.

OBSERVATION
The whole leaf becomes blue.

RESULT
Blue colour shows that starch is present in the leaf because iodine reagent gives dark blue colour with starch.

EXPERIMENT NO. 1
AIM
To prove that chlorophyll is necessary for the process of photosynthesis.

METHOD
Take a potted plant having varigated leaves. Destarch the plant by keeping the potted plant in dark. Wrap it in aluminium foil and expose it to the sunlight for few hours. Detach the leaf from the plant. Draw a rough sketch of the leaf. Apply iodine test on leaf, for the presence of the starch.

OBSERVATION
The test shows that the parts of the leaf which were previously green turn blue after iodine test while the white parts turn brown.

RESULT
This result indicated that starch is formed only in those parts of the leaf where chlorophyll exist. This shows that chlorophyll is necessary for the process of the photosynthesis.

EXPERIMENT NO. 2

AIM
To prove that light is necessary for the process of the photosynthesis.

METHOD
Destarch a potted plant by keeping it in a dark room for two days. It is then transferred to light. Select two of its leaves wrap one leaf completely with black paper. Wrap another leaf with black paper but L shaped part of the paper is cut out so that light can reach the leaf through it. Place the plant in sunlight for 4 to 6 hours. Detach both leaves from the plant and perform iodine test.

OBSERVATION
It will be observed that the leaf which is covered by paper is free from the starch (remain brown with iodine). In the second leaf the area which is receiving light will turn blue while the area which is covered will remain brown.

RESULT
This shows that light plays vital role in preparation of starch, which is prepared by photosynthesis. So it is concluded from this experiment that light is necessary for the process of photosynthesis.

EXPERIMENT NO. 3

AIM
To prove that CO2 is necessary for the process of the photosynthesis.

METHOD
Destarch two potted plants by keeping them in a dark room. Water them properly during this period. Each pot is enclosed in a transparent polyethene bag. A petri dish containing soda lime is placed in one of the pots to absorb CO2. In another pot a petri dish is placed containing sodium bicarbonate solution to produce CO2. Place the plants in sunlight for few hours. A leaf from each plant is detached and tested for starch.

OBSERVATION
The leaf from the pot containing soda lime does not turn blue. The leaf from another pot will turn blue.

RESULT
This experiment shows that CO2 is necessary for the process of photosynthesis.

EXPERIMENT NO. 4

AIM
To prove that oxygen is produced during the process of photosynthesis.

METHOD
Place the short stem funnel over the aquatic plant hydrilla in a beaker of water. Place the water filled test tube over the stem of funnel. Place the apparatus in sunlight.

OBSERVATION
Bubbles of gas will soon appear from the plant and will be collected in the test tube. Remove the test tube, bring a burning match stick near the mouth of test tube. It will burn with flame vigorously.

RESULT
This shows that oxygen is produced during the process of photosynthesis as the gas in test tube is supporting the combustion.

STORAGE OF FOOD
The food prepared by the plants is used in respiration and assimilation (formation of new protoplasm). The excess amount of food is stored in different storing tissues.

VAN HELMONT EXPERIMENT
He planted willow tree which weighted 2.3 kg. After 5 years he observed that weight of tree was 2.3 kg weight of soil was 91 kg. After next five years the weight of plant become 76.9 kg and weight of soil become 90.8 kg. Increase in weight of plant was 74.6 kg and decrease in weight of soil was 2 kg.

CONCLUSION
Van Helmont concluded from this experiment that decrease in weight was due to utilization of minerals from soil and increase in weight of plant was due to absorption of water from soil by the plant.

JOSEPH PRESTLY'S EXPERIMENT
Joseph Prestly enclosed one mouse in a jar in which potted plant was present and second mouse in a jar without plant. It was noticed that the mouse in jar without plant was died due to suffocation but the mouse in jar having plant remained alive.

CONCLUSION
It was concluded by Pristly that plant take some substance from the air and replace it with a substance which is essential for the life. Later it was found that plant take CO2 from the air and give oxygen in the air

Blood

Blood

Blood is composed of plasma and formed elements.

PLASMA

It consist of water, electrolytes, enzymes, hormones, vitamins, nutrients, fibrinogen, etc.

FORMED ELEMENTS

Formed elements consists of following parts.

RBC (RED BLOOD CELLS)

They are biconcave disc like cells. They are non nucleated cells. RBCs are formed in bone marrow. They contain a pigment called haemoglobin which carry oxygen.

WBC (WHITE BLOOD CELLS)

They are found in different sizes. They are nucleated. WBCs provide protection to our body from disease causing factors like bacteria, virus etc.

PLATELETS

These are fragments of cells. They are smaller in size. They play important role in blood clotting

Balance in the Nature

Balance in the Nature

It is the equilibrium maintained by an ecosystem between plants and animals and their non living environment is called balance in nature.

WATER CYCLE

The cyclic flow of water to its various reservoirs. The water on earth changes into vapours and condense to form clouds. These clouds precipitates and as the result rain falls on earth. Some of the water vapours are contributed by animals (by respiration) and by plants (transpiration) into the atmosphere.

OXYGEN CYCLE

Animals take oxygen from atmosphere and release CO2. The CO2 produced during respiration is utilized during photosynthesis. During night there is no photosynthesis so only CO2 is produced and oxygen is used by the plants.

CARBON CYCLE

Green plants photosynthesize CO2 into sugar. Most other organic molecules are made using sugar e.g., cellulose, protein etc. When these are eaten by animals the digested products are turned into animals carbohydrates, fats and proteins.

This variety of organic molecules is returned to air as CO2 during respiration in living organisms, or by combustion of fuels.

Fuels include wood and the fossil fuels coal and petroleum and natural gas.

NITROGEN CYCLE

Green plants need nitrates for protein synthesis. Nitrates are available to green plants from four sources:

1. MAN MADE FERTILIZERS

e.g., ammonia nitrate.

2. LIGHTENING

Cause formation of oxides of nitrogen.

3. NITROGEN FIXING BACTERIA

Convert atmospheric nitrogen into nitrates.

4. NITRIFYING BACTERIA

Oxidized ammonia compounds to nitrites and then nitrates.

Nitrates are turned into nitrogen gas by denitrifying bacteria if soil lack air as in water logged conditions. Nitrogen gas is useless for green plants.

Green plants form amino acids from nitrates. Proteins are made form amino acids. Animal convert protein to their own, but in doing so waste source e.g., urea and uric acid which is excreted.

Decomposers break dead organisms and their waste.

Multicellular Organisms

Multicellular Organisms

Living organisms consist on many cells are called multicellular organisms. Brassica and frog are representative examples of multicellular plants and animal respectively.