Diversity in Living Organisms
Biologists such as ErnstHaeckel,RobertWhittaker and Carlwoese
have tried to classify all living organisminto broad categories called kingdom.
The classification which Whittaker proposed has five kingdoms: monera, protista,
fungi, plantae and animals.
1. Monera : These organisms do not have a defined
nucleus nor do any of them show multi- cellular body designs. This group
includes bacteria, blue green algae, or cyanobacteria and mycoplasma.
2. Protista : These groups include many kinds of
unicellular eukaryotic organisms some of these organisms use appendages, such as
hair like cilia or whip like flagella for moving around. e.g. : unicellular
algae, diatoms, protozoans.
3. Fungi : there are heterotrophic eukaryotic
organisms. They are decaying organic materials as food and are therefore called
saprophytes. They have a cell wall made up of a tough complex sugar called
E.g. are yeast and mushrooms
- These symbiotic life form are called lichens. We
have all seen lichens as the slow growing large columned pitches on the bark of
DIFFERENTIATION IN PLANTS
- Plants that do not have well differentiated body
design fall in this group.
- The plants in this group are commonly called algae.
These plants are predominantly aquatic.
E.g. : Spirogyra, cladophora and chara.
- In this group plant body is differentiated into
roots, stem and leaves and has specialized tissue for the conduction of water
and other substances from one plant of the plant body to another. Egmarsilea,
ferns, and horse tails.
- The plant of this group bear naked seeds and one
usually perennial and evergreen and woody.
Eg- pines such as deodar.
The seeds develop inside an
organ which is modified to become a fruit. These are also called flowering
Plant embryos in seeds have structures called cotyledons. Cotyledons
are called seed leaves because in many instances they emerge and become
green the seed germinates.
The angiosperms are divided into two groups on the basis of the number
of cotyledons present in the seed.
Plants with seeds having a single cotyledon
are called monocotyledons or monocots. Egpaphiopedilum.
Plants with seeds having two cotyledons are
called dicots. Eg- ipomoce.
DIFFERENTATION OF ANIMALS
These are animals living in
water. The body is made up of two layers of cells. One makes up cells on the
outside of the body and the other makes the inner living of the body.
Some of these species live in colonies while others have
a solitary life e.g. span (Hydra) jellyfish are common example.
There are three layers of
cells from which different tissues can be made. This allow outside and
inside body linings as well as some organs to be madeThus
there is some degree of tissues formation.
They are either free living or parasitic. e.g.
Planarians, liver flukes.
There is an open
circulatory system and so the blood does not flow in well defined blood
vessels. They have joint legs. Eg- prawns, butterflies, houseflies, spiders,
scorpions and crabs.
These animals have a
true vertebral column & internal skeleton. These are grouped into five
These are fish. They are cold blooded and
their hearts have only two chambers unlike the four that human have.
Some with skeletons made entirely of cartilage, such as shark.
Some with skeleton made of both bones and
cartilages such as tuna or rohu.
These animals are cold
blooded have scales and breathe through lungs. While most of them have a three
chamber heart while crocodile have four heart chambers. Eg- snakes, turtles,
lizards and crocodiles.
They are warm blooded
animals with four chambered hearts.
They have mammary glands for the production of
milk to nourish their young. They produce live young ones.
However a few of them like platypus and the
echidna lay eggs.
MICRO ORGANISMS: FRIEND AND FOE
FACTS FROM NCERT
Micro organisms are classified into four major groups. These groups are
bacteria, fungi, protozoa and algae.
- Viruses : They reproduce only inside the cells of the host organisms
which may be bacterium, plants or animal.
- Common cold, influnenza and most coughs are caused by viruses.
- Serious diseases like polio and chicken pox are also caused by viruses.
- Micro organisms may be single celled like bacteria, Some algae and
protozoa. Multicellular such as algae and fungi.
- Micro organisms like amoeba can live alone,while fungi and bacteria may
live in colonies.
Friendly Micro Organisms
- Making of curd and breed:-milk is turned into curd by bacteria. The
bacterium lacto bacillus promotes the formation of curd.
- Yeast reproduces rapidly and produces CO2 during respiration. Bubbles of
the gas fill the dough and increase its volume; this is the basis of the use
of yeast in the booking industry for making breads, pastries and cakes.
- Yeast is used for commercial production of alcohol and wine. For this
purpose yeast is grown as natural sugars present in grains like barley,
wheat, rice,crushed fruit juice etc.
- This process of conversion of sugar into alcohol is known as
fermentation Luwis Pasteur discovered fermentation.
Medicinal Use of Micro Organisms:
- The medicine which kills or stops the growth of diseases causing
microorga-nism is called antibiotics.
- Streptomycin, tetracycline and erythromycin are some of the commonly
known antibiotics. Which are made from fungi and bacteria. 8 Alexander
Fleming discovered penicillin.
- Antibiotics are not effective against cold and flu as these are coused
- When a disease carryingmicrobe enters our body, the body produces
antibodies to fight the invader.
- The antibodies remain in the body and we are protected fromthe
disease causing microbes. This is how a vaccine work.
- Several diseases including cholera, TB, small pox and hepatitis can be
prevented by vaccination.
- Edward Jenner discovered the vaccine for small pox.
Increasing Soil Fertility
- Some bacteria and blue green algae are able to fix nitrogen from the
atmosphere to enrich the soil with nitrogen and increase its fertility.
- These microbes are commonly called biological nitrogen fixer.
- Microbial diseases that can spread from an infected person to a healthy
person through air water, food, or physical contact are called communicable
diseases. i.e.- cholera, common cold, chicken pox and TB.
- There are some insects and animals which act as carrier of disease
causing microbes like house fly. Another is female anopheles mosquito which
caries the parasite of malaria.
- Female aedes mosquito acts as carrier of dengu virus.
- Robert Koch discovered the bacteria (bacillus anthracis) which causes
- It is a dangerous human & cattle disease.
Common Methods of Preserving Food in our Homes
- Chemical method : salt and edible oils are the common chemical generally
- Sodium benzoate and sodium metabisulphite are common preservatives.
These are also used in the James and squashes to check their spoilage.
Preservation by sugar :
- Sugar reduces the moisture context which inhibits the growth of bacteria
which spoil food.
- Use of oil and vinegar prevents spoilage of pickles
Some Common Plant Disease Caused by Microorganisms
||Mode of Transmission
|Rust of wheat
|Yellow vein mosaic of bhindi
Some Common Human Disease Caused by Micro Organisms
||Mode of transmission
||Keep the patient in complete isolation.
||Keep the person
||belonging of the patient
||away from those of others
Vaccination at suitable age.
||Maintain personal hygiene and good
||sanitary habits. consumed properly
cooked food and boiled drinking
||Drink boiled drinking water
||Spray insecticides and control
breeding of mosquito
FACTS FROM HUMAN MACHINE
- Camels have long legs which help to keep their bodies away from the heat
of the Sand. They excrete small amount of urine, their dung is dry and they
do not sweat. Since Camels lose very little water from their bodies, they
can live for many days without water.
- Fish have slippery scales on their bodies. These scales protect the fish
and also help in easy movements through water. The presence of specific
features of certain habits, which enable a plant or an animal to live in its
Surroundings, is called adaptation.
- There are some sea animals like squids and octopus, which do not have
this streamlined become bacteria cannot live in such an environment.
- Pasteurized milk : the milk is heated to about 70oc for 15 to 30 seconds
and then suddenly chilled and stored.
- This process was discovered by lowise Pasteur. It is called
pasteurisation.shape. These animals have gills to help them use oxygen
dissolved in water.
- There are some sea animals like dolphins and whales that do not have
gills. They breathe in air through nostrils or blowholes that are located on
the upper parts of their heads. This allows them to breathe in air when they
swim near the surface of water. They can stay inside the water for a long
time without breathing. They come out to the surface from time to time, to
breathe in air.
- When we breathe out, the air moves from inside out body to outside.
Breathing is part of a process called respiration. In respiration,
some of the oxygen of the air we breathe, in used by the living body.We
breathe out the Carbon dioxide produced in this process.