Download Adaptations in Living Organisms STD: 6 2013-2014

Adaptations in Living Organisms
STD: 6
2013-2014
Answer the following questions:
Q1) Why is the camel called “The Ship of the Desert’?
Ans) The Camel is known as the ship of the desert because it can move across desert sands
easily providing a mode of transportation for people in desert areas. The hot sands of the
desert do not hinder its movement. The fat in a camel's hump enables it to travel long
distances without food or water. Camels have a double row of long lashes to protect their
eyes from blowing sand in the desert. They are also able to close their nostrils to avoid
breathing sand.
Q2) Why are leaves of the cactus plant reduced to spines?
Ans) The leaves of the cactus plant are reduced to spines to reduce water loss
through stomata by transpiration.
Q3) What enables yaks to survive in extremely low temperatures?
Ans) They have thick hair on their bodies to keep warm. They use their horns and hooves to
break ice on the ground and graze on the grass present below.
Q4) Name the components of a habitat. How are they different from each other?
Ans) All habitats are made up of two components – biotic and abiotic.
Biotic component consists of all the living things in the habitat such as plants,
animals and other living organisms. Abiotic component includes all the non-living
things such as stones, soil, air, paper, etc.
Q5) Enlist two problems faced by organisms living in desert region.
Ans) Rainfall is scanty, less than 25cm annually.
It is usually very hot during the day with temperatures soaring above 50°C and cold
at night with temperatures dipping as low as 0°C
Q6) Describe the adaptive features of hydrophytes.
Ans) The following are the adaptive features exhibited by free floating and partly
submerged hydrophytes:
 The roots are either poorly developed or totally absent.
 The leaves are tough and can withstand the movement of water. They are covered with
cuticle so that water does not collect over them.
 Stomata are found on the upper surface of the leaves.
 Chlorophyll is largely localised in the upper parts of the leaves.
 The stem of the plants that are rooted are long and narrow and offer least resistance to the
flow of water. They are hollow and have lots of air spaces to provide buoyancy to the
plant.
Water lily
Duckweed
The following are the adaptive features exhibited by fully submerged hydrophytes:
 The roots are either absent or very poorly developed and only provide anchorage.
 Stomata are absent since gaseous exchange occurs through general body surface.
 There is no waxy coating since there is no threat of water loss.
 Leaves are either ribbon-like or highly divided.
 The body tissue has numerous air spaces to keep the plant light and float.
 Water transporting system is poorly developed.
Hydrilla
Vallesneria
Q7) How are animals adapted to live successfully in aquatic habitats?
Ans) – Aquatic animals have streamlined bodies that help them in swimming.
- Organisms such as fish have gills to breathe and fins that help to swim.
- Whales and dolphins have blow holes to take in oxygen at the surface of water.
- Aquatic birds such as ducks have webbed feet for swimming.
Dolphin
Whale
Fish with gills
Q8) What are the special features of grasses found in grasslands? Name two
commonly found grasses in the region.
Ans) – Plants have a well developed deep root system.
- Presence of thin leaves prevent loss of water.
- The stalks of leaves are flexible to withstand strong wind currents.
* Andropogon and Koeleria are two commonly found grasslands in the region.
Q9) What is adaptation? How is it beneficial for the living organisms? Give two
examples to explain.
Ans)The specific features and behaviour of organisms that enable them to survive
successfully in a particular habitat is called as adaptation.
It enables the organisms to live and survive in that particular habitat.
Ex.1: Mountain goats have strong hooves that they use to move up and down the rocky
terrain.
Ex.2: Snow Leopards have thick skin or fur that protects them from cold.
Q10) What is camouflage? Explain with the help of examples.
Ans) A method of hiding adopted by many living organisms to blend with their surroundings
without being noticed is called camouflage.
Ex.: Lions are light brown in colour that help them match with the surrounding dry grass and
makes their presence unnoticeable to their prey. This skin colour helps them to camouflage.
Q11) What is the type of habitat in which a conifer is likely to be found. Enlist its
adaptive features.
Ans) Conifers are likely to be found at higher altitudes in mountainous region.
 They are conical in shape, which allow the snow to slide off easily.
 The leaves have a needle-like shape and are covered with a waxy coating. These prevent
loss of water due to transpiration.
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