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Living things in their environment - Grade 6

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Checkpoint Science (Grade 6)
4. Living Things In Their Environment
 Habitats:
A habitat is the place where an organism or a community of organisms lives. A habitat includes all living and
non-living factors or conditions of the surrounding environment. Almost every place on Earth—from the
hottest desert to the coldest ice pack—is a habitat for some kinds of living things.
Every organism has its own habitat and they adapt accordingly. This is where the organism meets its basic need for
its survival: food, water, shelter from the weather and place to breed its younglings.
Habitat can be terrestrial (land) or aquatic.
Terrestrial habitat includes forests, grasslands, deserts, coastal and mountain regions.
The aquatic habitat includes freshwater habitats (lakes, ponds, rivers and streams, wetlands, swamp, etc) and
marine habitats (oceans, intertidal zone, reefs, seabed, etc.).
There are different types of Habitats.
Rainforests habitat: These are lush, warm, wet habitats. Trees in the rainforest grow very tall because
they have to compete with other plants for sunlight. Kapok trees, which are found in tropical rainforests
around the world, can grow to 200 feet. Plants: Orchid, vine, moss, and fern. Animals: Bat, gorilla, monkey,
sloth, macaw, and variety of insects.
Freshwater habitat: Rivers, lakes, ponds, and streams are examples of freshwater habitat. Fish, frog, duck,
lotus, and water lily are found in fresh water,
Marine water habitat: Oceans and seas form the largest habitat on the planet. Some commonly found
animals are whale, dolphins, sharks, octopus, starfish, jellyfish, seahorse, etc, and plants, seaweeds are the
most common.
Dessert Habitat: Deserts are areas that receive very little rainfall less than 25 cm annually. In hot desert,
daytime temperature in summer can reach 45 degree Celsius. Organisms such as cactus, camel, gila monster
and kangaroo rat are found here.
Polar Habitat: Polar and mountainous regions are the coldest of all the habitats found on earth. These
include the Arctic and the Antarctic regions. In the Antarctic, the lowest temperature recorded was -88
Degree Celsius. Animals such as polar bear, penguin, seal and walrus are found in Polar Regions.
Aquatic Habitat :
Streamlined body helps to
Grassland Habitat
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Polar Habitat
Forest Habitat
Adaptation: Adaptation is how a species changes its body and behaviour to better suit its natural
Plants and animals adapt themselves to exist in very cold as well as hot climate. The natural environment is an
ever-changing feature of planet earth. The organisms need to adapt themselves to these changes to survive; the
organisms which cannot adapt die out. . Thus process of adaptation ensures that the species which adapts the
most, survive.
Different kinds of organisms are present in different habitats as they adapt to different abiotic changes in
different ways.
1. Plants present in desert lose very little water through transpiration. They are adapted to this by having
small leaves or spine shaped leaves and sometimes even the leaves are absent. They also have thick wax
coated stem, and roots are long to go very deep in to the soil.
2. Different plants and animals found in mountains are adapted to the cold and windy climate and even from
snowfall in different ways.
Trees have cone shaped sloping branches with needle like leaves so that rainwater and snow can slide off
easily. Animals have thick skin or fur or hair to protect them from cold. For example yak, snow leopard. The
mountain goat is an animal has strong hooves for running up the rocky slopes of the mountains.
3. Prey and predators found in grasslands adapt several features to survive. For example, i) a lion and ii)a
A lion is a prey wants to eat animals have long claws in the front legs , light brown colour, eyes in front of
the face which allows it to hunt animals and kill its prey.
4. Fishes have streamlined bodies to move easily inside water.
Other sea animals which do not have streamlined body stay very deep inside the ocean and when they
move in water they make their body streamlined.
Some animals have gills to use dissolved oxygen.
Some animals like dolphin breathe air through blowholes located on the upper parts of their head.
Dolphins can stay inside water without breathing for a long time and when needed come out to the surface
to breathe in air.
5. The aquatic plants have roots fixed in the soil and only hold plants in place.
Stems are long, hollow, light and grow above the surface of water and leaves, flowers, float on the surface
of water.
Some aquatic plants are found to be totally submerged in water and these have highly divided leaves for
the flow of water without damaging them.
Frogs are found both in water and land. Their strong back legs help them in catching prey and webbed feet
to swim in water.
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Checkpoint Science (Grade 6)
Desert Habitat:
Thorns to prevent
water loss
Food chains and food webs:
Food chains and webs describe the transfer of energy within an ecosystem, from one organism to another.
Food chains and food webs are diagrams that represent feeding relationships.
A food chain is a series of organisms that eat one another so that energy and nutrients flow from one to the
A food chain represents a single pathway by which energy and matter flow through an ecosystem. Food chains
are generally simpler than what really happens in nature.
Aquatic Food Chain
Terrestrial Food Chain
A food web represents multiple pathways through which energy and matter flow through an ecosystem.
Sometimes, a single organism gets eaten by many predators or it eats many other organisms. This is when a food
chain doesn’t represent the energy flow in a proper manner because there are many trophic levels that
interconnect. The diagram then used is called Food Web. It includes many intersecting food chains. It
demonstrates that most organisms eat, and are eaten, by more than one species.
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Energy Pyramid:
An Energy Pyramid is a diagram that shows the flow of energy from one trophic level to the next in
an ecosystem. This diagram compares the energy used by organisms at each trophic level.
The structure of an energy pyramid reflects the trophic structure of an ecosystem. The pyramid is divided into
trophic levels similar to those in a food chain.
Energy pyramids can be represented as pyramid of biomass or pyramid of numbers.
 Pyramid of biomass represents the amount of biomass at each trophic level in an ecosystem.
The population of species in a food chain is shown using a Pyramid of numbers. Organisms in an
ecosystem affect each other’s population.
The trophic level of an organism is the position it occupies in a food web.
At the base of the food chain lie the primary producers. The primary producers are autotrophs and are most
often photosynthetic organisms such as plants, algae etc.
Producers use energy from sunlight to make their own food. A food chain always starts with a producer.
The organisms that eat the primary producers are called primary consumers. Primary consumers are
usually herbivores, plant-eaters, though they may be algae eaters or bacteria eaters.
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The organisms that eat the primary consumers are called secondary consumers. Secondary consumers are
generally meat-eaters—carnivores.
The organisms that eat the secondary consumers are called tertiary consumers. These are carnivore-eating
carnivores, like eagles or big fish.
Some food chains have additional levels, such as quaternary consumers—carnivores that eat tertiary
Decomposers are organisms that carry out decomposition (break down) of dead or decaying organisms.
Fungi, bacteria, worms and insects acts as decomposers in nature.
The shape of an energy pyramid shows that the amount of food energy that enters each trophic level is less
than the amount that entered the level below. Approximately 90 percent of the food energy that enters a
trophic level is “lost” as heat when it is used by organisms to power the normal activities of life such as
breathing and digesting food; the remaining 10 percent is stored in the various organisms’ tissues. It is this
latter energy that is available to be passed to the next trophic level. Thus, the higher the trophic level on the
pyramid, the lower the amount of available energy.
The number of organisms at each level decreases relative to the level below because there is less energy
available to support those organisms. The top level of an energy pyramid has the fewest organisms because it
has the least amount of energy. Eventually there is not enough energy left to support another trophic level; thus
most ecosystems only have four trophic levels.
Some examples of food chain explained below:
1. An earthworm breaks down dead organic matter in the soil which the plants, sitting one level up in the
pyramid, utilize to manufacture their food along with the light from the sun during
the photosynthesis process. The herbivores in the next level up in the pyramid, in turn, use the stored energy in
the plants by feeding on the plants. The energy contained in the fecal matter from the herbivores is recycled
back into the system where it is broken down further by the earthworms.
2. Mice on the forest floor eat the seeds and fruits of trees, shrubs, and flowers for energy. The eagle, sitting at
the next level up the energy pyramid eats the mice, taking in the energy they have stored. It is worth noting that
adult eagles have no natural predators. That means they occupy the topmost level of their energy pyramid.
3. Grasshoppers eat grass for their energy. The grasshoppers, in turn, give their energy to frogs in the next level
up the pyramid, which feed on them. Snakes in the next level of the pyramid get their energy from frogs and so