Download Components of the environment

Ways of Living
Habitat: It is the dwelling place or a place where an organism lives. It offers to an organisma. Food
b. Shelter
c. Proper climatic conditions
Components of the environment
The environment consists of two components:
a. Abiotic components
b. Biotic components
Abiotic components:
a. Light
b. Temperature
c. Air or Wind
d. Humidity
e. Pressure
f. Water
g. Climate, etc.
Biotic Components:
a. Producers (Autotrophs) eg. Green Plants.
b. Consumers (Heterotrophs) eg. Non-green plants, animals, man, etc.
c. Decomposers (Microorganisms) eg. Bacteria, Fungi, etc.
Microhabitat: It is defined as a small, specified and effectively isolated unit within a habitat.
It is characterised by the presence of special features, which suit some organisms better than
others. Eg. Organisms that live on a tree bark – is a microhabitat.
Interdependence: It is the relationship between two or more organisms.
Eg. 1. Plants depend upon plants.
Eg. 2. Plants depend upon animals and vice-versa.
Eg. 3. Animals depend upon animals.
Various kinds of interdependence:
Mutualism or symbiosis – It is the relationship between two organisms in which both are
mutually benefited. Each partner of the relationship is called a symbiont.
a. Rhizobium bacteria on the root nodules of legume plants (eg. Peas, beans, etc.) :
Legume plants have root nodules, which provide food and shelter to the bacteria Rhizobium.
Rhizobium in turn fixes atmospheric nitrogen and converts it into nitrates which can be
absorbed by legume plants as nutrition.
b. Algal cells and fungal hyphae in lichens:
Alga obtains nitrogen, minerals and water from the Fungus, whereas the fungus receives
carbohydrates from the Alga. Thus lichens thrive in the environment.
c. Egret birds on buffalo:
Egret birds eat the lice, ticks and other insects on the hide and skin of the animal. The buffalo
benefits in the process because it is freed from the trouble from the insects and the egret
benefits from the free food supply.
d. Tick bird and Rhinoceros:
Tick birds eat the lice and ticks on the body of the Rhino, the Rhino benefits in the process
because it is freed from the trouble from the insects and the tick bird benefits from the free
food supply.
e. Ostriches with herds of zebras and antelopes:
Ostriches act as watchmen and sentinels and get their food from the herds.
Adaptation: The development of characteristics which help an organism to survive in a
particular environment is known as adaptation.
Various habitats and adaptations of organisms:
Habitat adaptations in plants:
Xerophytes: The plants that grow in the desert where there is scarcity of water are called
xerophytes. Eg. Cactus, opuntia, asparagus, Euphorbia, Yucca.
Adaptations:
a.
b.
c.
d.
They have well-developed root system and have root hairs to absorb water.
Leaves are reduced, small, scale-like and/or modified into spines.
The stomata are few, sunken in pits or covered by root hairs.
Stems are fleshy and green to carry out photosynthesis.
Hydrophytes: Plants that grow in water are called hydrophytes.
Eg. Free floating: Wolfia, lemnia, pistia, Eichlomia
Eg. Rooted with floating leaves: Nymphea, Water lily, marsilea, nelumbo.
Eg. Submerged floating : Ceratophyllum, utricularia.
Eg. Rooted submerged : Chera, Vallisneria, Hydrilla.
Eg. Rooted emergent : Typha, Rumex, Sagittaria.
Adaptations:
a.
b.
c.
d.
e.
f.
The roots are poorly developed with no root hairs or root caps.
Leaves are mostly large, thin with waxy coating and repel light.
The stem is long, soft, slender, spongy and weak with little woody tissues.
The tissues of aquatic plants have air spaces to keep the plant afloat.
The stomata are many and are usually found on the upper part of the leaves.
The have many large tunnels and holes for air, that help them to stay up.
Mesophytes: Plants that grow in moist habitats that contain well-aerated soils are called
mesophytes.
Adaptations:
a.
b.
c.
d.
e.
They have a well-developed root system.
The stem has mechanical tissue and the vascular system is well developed.
The leaves are usually thin.
The leaves have stomata on both the surfaces mainly on the lower surfaces.
They are found in all climates and different soil conditions.
Eg. Banyan, Mango, Plum, Peach, etc.
Habitat Adaptations in Animals:
Aquatic adaptations: (in Latin Aqua=Water) Animals that live in water are called aquatic
animals.
Adaptations:
a.
b.
c.
d.
e.
The body is streamlined without a neck.
The have a powerful tail and fins for locomotion.
The gills help in respiration.
Bony fishes have air bladder to make floating easier.
They have special coverings such as shells, cuticle, waxy coating, scales to
prevent water loss, rotting and decay.
f. They possess a filter feeding mechanism.
g. They possess lateral line system to detect the enemy through vibrations.
Eg. Fishes, Crabs, Molluscs, etc.
Terrestrial Adaptations: Animals that live on land are called terrestrial animals. (In Latin,
Terra=Ground)
Adaptations:
a.
b.
c.
d.
e.
Animals have lungs for breathing.
The body is covered with scales or hairs.
The nervous system is well developed.
They have sense organs for sensing various changes in the environment.
The limbs are well developed and suited for walking, running, jumping, etc.
Eg. Horse, dog, lizard, snake, man, etc.
Amphibious Adaptations: (In Greek, Amphi=both sides; bios=life) Animals that can live both
on land as well as in water are called amphibious animals.
Adaptations:
a.
b.
c.
d.
e.
The skin is moist slimy and helps in breathing.
The lungs are also used for breathing on land.
The hind legs are long and strong so as to help in leaping movements on land.
The feet are modified into paddles for swimming.
They are mostly cold-blooded or ectothermic animals.
Eg. Frogs, Toads, Salamanders, crocodiles, turtles, etc.
Cold-blooded or ectotherms: Animals that can adjust their body temperature to that of the
environment are called cold-blooded animals.
Endotherms or warm-blooded animals or homeotherms: Animals that cannot adjust their
body temperature to that of the environment and possess a constant body temperature are
called warm-blooded animals.
Aerial adaptations: The animals that are adapted for aerial mode of life (flying) are called
volant animals.
Adaptations:
a.
b.
c.
d.
e.
f.
g.
h.
i.
The body is streamlined.
The body is covered with feathers.
Fore limbs are modified into wings.
The bones are light, hollow, spongy, fused and contain many air cavities.
The sweat glands are absent.
The oil glands are present.
They possess a very good sense of sight.
The beaks are adapted for feeding and the feet for perching the trees.
They possess strong flight muscles.
Eg. Birds, bats, etc.
Adaptations of Chameleon:
a.
b.
c.
d.
The chameleon can change its body colour to resemble its surroundings.
The feet have digits in-groups of two and three to grasp branches firmly.
It has a prehensile tail, which acts as the fifth limb.
The eyes are elevated and the eyeballs can rotate in all directions. They also act
independently.
e. It has a long sticky tongue which is rolled up like a spring and is well adapted to
its feeding habit.
f. Its dry skin, stick like legs and compressed body help in climbing walls and trees.
Adaptations of Camels: The Camel is called the ship of the desert.
Adaptations:
a. They hooves are covered with a large soul, which helps it to move on hot slippery
sand.
b. The hump on Camel’s back is a food reserve filled with fat that can be utilised at
the time of need.
c. It has a slender snout, which bears a cleft upper lip, long eyelashes and muscular
nostrils that can be closed to protect from sandstorms.
Adaptations for the conservation of water:
a. It can drink three buckets of water in one gulp, which is distributed all over its body
tissues. This helps the camel to stay for long without water.
b. It excretes very little, highly concentrated urine.
c. Its dung also contains very little water.
d. It perspires very little and its breathing rhythm is very slow.
e. It can withstand dehydration upto 25% of its body weight.
f. It can adjust its internal temperature to that of the surrounding air and hence, the water
loss is greatly reduced.
Advantage of the long tongue of chameleon:
The advantage of the long tongue of the chameleon lies in catching the prey from a
distance at lightening speed.
Desert animals are nocturnal:
In the desert the climate is so hot so they dig holes and burrows and live within. The
burrows below the hot sand surface offer moist and cool home. At night when the desert
cools these animals become active.
Hibernation: The winter-sleep is called hibernation. Eg. Bats, polar bear, etc.
Aestivation: The summer sleep is called aestivation. Eg. Snail, etc.
Physical factors influencing land organisms:
a.
b.
c.
d.
e.
f.
g.
Soil
Temperature
Humidity
Light
Oxygen or air
Water
Human Beings
Physical factors influencing aquatic animals:
a.
b.
c.
d.
e.
Availability of Oxygen
Availability of light
Pressure fluctuations
Resistance to motion
Salt concentration
Adaptations of Orchid plant:
a. The stems act as reservoir of water.
b. Their leaves are specially evolved to keep water in and dryness out.
c. They have wandering roots that are looking for moisture, taking in as much as they can,
during the rainy season.
Adaptations in Animals that live in Polar region:
a. They are usually white or light coloured. This helps in camouflage and internal
regulation.
b. Animals eat a lot during summer and autumn and store the energy in their bodies as fat.
c. During severe winter they hibernate for months to reduce metabolic activity.
Adaptations of plant in snow bound region:
a. They are short in height.
b. They remain dormant for months.
c. They possess narrow leaves or spines that they shed rapidly.
- Kshitij Misra