INTRODUCTION
We have to
live in harmony with our surroundings. We are helped by several animals and
plants around as and in turn, we must understand and fulfill their
requirements. It is thus very essential for us to differentiate between
useful and harmful plants and animals. In this project we will study about
various plants and animals which are useful to us and also about those that
cause us harm.
Useful PLANTS:
DEFINITION:
A large number of plants and their products are used for
the well being of mankind. They provide us with food, clothing and shelter.
They also provide raw materials for many industrial products. Numerous plants
have medicinal properties. Ornamental plants add to beauty. Many of the
useful plants occur in nature in forests and a good number of them are
cultivated for food and industry.
In general, the useful plants can be grouped into the
following categories:
1. Food Producing
2. Fiber Yielding
3. Timber Yielding
4. Medicinal
5. Ornamental Plants
6. Other Useful Plants.
Food Producing Plants :
The early nomadic men gathered wild plants and hunted
animals for their food. As they began settling down in particular areas, they
started collecting seeds and planting them. This marked the beginning of
agriculture. The following are some of the major food plants cultivated in
India: Cereals, pulses, vegetables and fruits.
All cereals are rich in carbohydrates, proteins and
vitamins A, B and C. They are cultivated as annual crops. Rice, wheat and
maize are the major cereals while Jowar and Bajra are millets. Cereal
cultivation in India occupies about 60% of the total land under cultivated.
Pulses :
The seeds of some plants are used as food. These seeds are
known as pulses and they contain proteins in large amounts in addition to
carbohydrates and vitamins.
Vegetables :
Vegetables constitute an important part of the daily diet.
There are variety of plants whose edible parts are caten raw or are cooked
for preparing delicious dishes. The vegetables include roots, leaves, flowers
and even unripe fruits. The vegetables are very important because they
contain minerals salts and vitamins.
Fruits :
In economic botany, the term fruit is commonly used for
only those which are eaten without cooking. A large number of plants are
cultivated in India for their fruits. Some, like mangoes and bananas, are
even exported. Other fruits common in India are guava, papaya, pineapple,
orange, pear, custard - apple, grapes, litchi, etc. They provide not only
carbohydrates but also vitamins.
Edible Oils :
We get oils which are used as cooking media from plants.
Oils are changed into fats in our bodies. Groundnut oil, mustard oil,
sunflower oil, cottonseed oil, and coconut oil are some of the commonly used
oils. Oils are also utilized for the manufacture of soaps.
Spices :
The edible materials which are used more for their
aromatic flavor than for their food value are known as spices. Spices are
generally derived from different parts of the plants, like shoots, stems,
leaves, flowers, seeds, etc. Ginger, turmeric, cinnamon, cloves, cardamom,
saffron, chilies (red and green peppers), black pepper, fennel, coriander,
cumin, mustard seeds are commonly used as spices and condiments.
Fiber Yielding Plants :
The fiber yielding plants are second only to the food
yielding plants in importance. Man has been dependent on these plants for his
clothing and for a variety of other needs from times immemorial.
Timber Yielding
Plants :
All trees can yield wood which can be used as fuel when
they are dried
Medicinal Plants :
The most important of all the plant products used as
medicines are antibiotics. Antibiotics are substances produced by
micro-organisms like fungi and bacteria e.g., penicillin produced
penicillium.
Ornamental Plants :
Flowering plants that are grown in private and public
gardens for their beauty are called ornamental plants. Rose, magnolia,
bougainvillea, zinnia, balsam, lily, money plant and many other plants are
grown for their beautiful flowers.
Other Useful Plants :
Gum :
Gums are the familiar exudates of the plants of the dry region.
Resins : Resins
occur as secretion in special ducts and canals in different parts of the
plants.
Tannins :
Tannins are found in almost all the plants but only some plants contain
substantial amount.
Rubber :
Rubber which we use in the manufacture of tiers, tubes, raincoats, belts,
sports goods, etc.
Perfumes
:
Perfumes are sweet smelling oils extracted or obtained from flowers like
rose, jasmine, lavender, champa, saffron etc.
Harmful Plants :
Most of flowering plants are cultivated and used by man
for his benefit. But many are known to produce poison. Poison can be
described as a substance which is injurious to health or which can destroy
life.
White Cedar is a small neem-like tree with attractive
yellow fruits. These are lethal if taken by children and cause vomiting,
diarrhea and difficulty in breathing in adults. Datura poison, when
administered in small doses over a long period can act as obtained from poppy
seeds in mild doses serves as a sedative but an overdose can cause death.
useful animals
Definition :
Since the beginning of human civilization man has been
domesticating animals to use them for his own work and food. But unlike
plants, the number of useful animals is not very large. Useful animals play a
significant role in the welfare of mankind. We keep certain animals not only
as pets but also to serve some specific purposes. e.g. hens for eggs and cows
for milk, etc.
Animal Husbandry :
The
study of all the aspects of rearing the livestock is collectively known as
animal husbandry. In the rearing of animals, four factors have to be
considered. They are :
1. Breeding 2. Feeding
3. Weeding 4. Heeding.
Breeding :
We
want the animals with desired characters. The controlled multiplication of
animals to maintain or improve their qualities is known as selective
breeding. Man has been able to produce many breeds of different animals which
meet his requirement.
Feeding :
Food is essential for all living beings. When the young
calves start taking solid food, they need to be given balanced diet in the
farm to get healthy animals.
The feed normally given in a cattle farm is a mixture of
ordinary grasses and alfa-alfa (a legume) with clover (also a legume rich in
protein).
Weeding :
When some animals of the livestock develop certain
undesirable qualities, they have to be eliminated in order to prevent the
spreading of these qualities to the other animals and the next generations.
Also it is uneconomical to house and feed these animals. This elimination is
known as weeding.
Heeding:
Heeding means the proper care and management of animals.
Care must be taken to maintain the health of the livestock. Some very simple
practices are followed by farmers on caring their animals. These are
(i)
Providing the animals food regularly and properly.
(ii)
Cleaning out their drinking trough and putting in clean water.
(iii)
Erecting the sheds away from human habitations to maintain sanitary
conditions and cleaning the sheds regularly.
(iv)
Cleaning the animals regularly.
Smaller Animals :
Many smaller animals are useful to us. Goat, pig, chicken
and fish are used as food. Sheep are used for fur and wool. The other kinds
are small insects like lac insect, silkworm and the honeybee. They produce
certain materials at some stage of their life-cycle which are of great
economic importance to man. Because of this, these insects are reared on a
large scale.
Sheep and Goat :
Sheep and goat are reared for their wool, milk, fur and
hide. They move about in groups known as 'flacks' and the reared in dry lands
with low rainfall.
Pigs :
Pigs are domesticated for their meat (pork) and hide. The management and
breeding of pigs are together known as piggery. The shelters for pigs called
sties are made of straw and bamboo or wood.
Chicken (Poultry) :
Domestication of a group of birds (chicken, geese, turkey
and duck) for the purpose of obtaining eggs and meat from them, is known as
poultry farming.
The domestic fowls can be identified as males and females
on the basis of certain external characteristics. The cocks (male) have a
plumped tail, a comb and wattles on the head.
Fish :
Rearing and managing of fish for large scale production is
known as pisciculture (Pisces means fish). The Indian subcontinent is
surrounded on three sides by water and the coastal areas provide a rich haul
of fish. They are a major source of animal protein. Now-a-days fish and other
aquatic animals are cultivated on an industrial scale in large water
reservoirs.
Leather :
Skins of many animals are used for making leather. The
principal animals in leather industry are goats, sheep, cows, buffaloes,
lamb, snakes, lizards, tigers, crocodiles, varanus, etc. The skin of cow is
allied kips and that of the buffaloes as buffs.
Fur :
Furs are the soft 'down' dense growth of fibres (small
hairs) covering the skin of certain animals (mammals). Valuable furs are
obtained from those regions where the winter temperature is low and the
growth of the fur on animals is thick and luxuriant.
Lac :
Lac is a resin-like substance, secreted from the body of
an insect called Trachardia lacca. Lac insects live on the twigs of certain
plants like peepal, palas and ber. This secretion gets stuck to the branches
of the trees. The scrapping of the trees and processed to prepare shellac
which is widely used in varnish, polish, printing ink, etc.
Ivory
: Elephant teeth are cut out and ivory products are made from them. Horns
of animals are also used for making ornamental items.
Pearls
: Pearl is a white, highly shining globular concretion found within the
shell of an oyster (a kind of shell fish). It forms as a natural process in
the oyster when an irritant and gets into its shells. Pearl is used in
making ornaments and is quite expensive. Now-a-days pearls are made in a
large scale by culturing oysters in controlled conditions.
Lime
: Lime is made by burning shells of some moll uses since shells are
essentially compounds of calcium.
Pharmaceuticals
:
A number of
drugs are prepared from the animals and animal products. Insulin is
manufactured from the pancreas of cow and pig. Heparin and Vitamin B-Complex
are prepared from the liver of animals. The Capsules used in pharmaceutical
industries are made up of gelatin which is obtained by boiling the horns,
hoofs, skin, tendons and bones of animals.
Some Harmful Animals :
There are certain animals and insects which cause a lot of
harm to our health and also to our crops. Such animals and insects are known
as pests.
(i) Some
insects, like grasshoppers, beetles and rice weevils, cause enormous damage
to our agricultural crops and thus affect their yield.
(ii) A
number of insects feed on flowers and fruits and they can spread viral
infections.
(iii)
Caterpillars or larvae of many insects feed on the leaves on which they live.
(iv)
Certain mammals (rodents) like rats and rabbits eat up stored grains. Stored
grains are also attacked by many kind of moths, caterpillars and beetles.