A natural magnet is an ore of iron that attracts small pieces of iron, cobalt, and nickel towards it. It is usually an oxide of iron named Fe₃O₄. Magnetite or lodestone is a natural magnet.

Removal of harmful waste from the body is called excretion. Many wastes are produced during various metabolic activities. These need to be removed in time because their accumulation in the body can be harmful and even lethal for an organism. 

 Grasslands are places where fast-running animals live. Since there are almost no trees in grasslands, animals can run at their top speeds without bumping into things. Both cheetahs and ostriches, known for their swiftness, make grasslands their home. Other animals living in grasslands include zebras, giraffes, white rhinoceros, warthogs, grasshoppers, and vultures.

Silver using glass as mirror because it has high metallic lustre which lasts for long time n it is easily available . It has high reflective index. The back of a common flat mirror is silvered for convenience and durabilty.

Shadows are formed when the light gets obstructed by an opaque object. The formation of shadows also depends upon the distance between the opaque object and the screen. In this case the bird is opaque body and the Earth's surface is a screen. When the bird is flying high in the sky the distance between the body and the surface of the Earth is too large and hence even though the light is obstructed by the bird's body it cannot cast its shadow due to the large distance. If the bird is flying near to the Earth's surface then the shadow is formed as the distance between the bird and the earth is less. Hence, birds flying high in the sky do not cast shadow.

Frog: A frog has long hind limbs which help it in jumping on the ground. Its webbed feet help it in swimming in water. The frogs lay eggs in water. The sticky tongue of frog helps it in catching its prey.

Plants produce two gaseous waste products i.e. oxygen during photosynthesis and carbon dioxide during respiration. Excretion of gaseous waste in plants takes place through stomatal pores on leaves. Oxygen released during photosynthesis is used for respiration while carbon dioxide released during respiration is used for photosynthesis.

Excess of water is also excreted from the plant body through the stomatal pores and from the surfaces of fruits and stems. The process of elimination of water is called transpiration.

It does not matter in which side seed is sown. If seed is sown upside down in soil, the root will always grow towards gravity that is downwards and stem will grow upwards.
This shows the growth movement in plants. This proves growth occurs in living organisms.

She needs to cut a piece of strong and healthy rose stem about 6 inches long and remove the bottom set of leaves. Next, she needs to stick the stem into a pot of garden soil, a couple inches deep. She must periodically water the soil, otherwise the rose stem will dry out. She will observe new shoots sprouting form the buds. Repeated this procedure with a number of stems cuttings and she will have many rose plants in her garden.

A moving car although moves is not considered as a living organism because of the following reasons:

1. Living organisms have the ability to move on their own, whereas a car moves by burning of fuels like diesel and petrol.
2. A car does not show any other living characteristics like respiration, digestion, reproduction or growth, that are shown by all living organisms and these processes are essential for living beings.

 Reproduction is the characteristic of living organisms through which they produce more of their own kind.
Thus, even after the organisms die, their kind continue to live on earth.

 A small amount of concentrated urine would be excreted in desert. This will help conserve water in the body.

Respiration is the chemical process in which food is taken by an organism combines with oxygen to release energy.

The oxygen reacts with the food present in the body cells and burns them slowly to release energy. When the breakdown of glucose food occurs with the use of oxygen it is called aerobic respiration. The glucose food is completely broken down into carbon-dioxide and water with the use of oxygen and energy is released.

All cells of our body produce waste products. These waste products are toxic to the body and therefore need to be excreted out. This process of removing waste products produced in the cells of living organisms is called excretion.

1. Endothermic
2. Two legs
3. Lay eggs
4. Some birds have webbed feet or 4 long spreading toes
5. Feathers are the defining characteristic of Aves, found on every living species of bird and no other class of animal.
6. All birds have wings, although not all birds fly.

Camel lives in hot desert where water is scarce. Its body structure helps it to survive in desert conditions. The special features which help the camel to survive in desert are:

1. It has long legs which help to keep its body away from the hot sand in the desert.
2. It can drink a large amount of water and store it in the body.
3. It is adapted to save water in the dry desert by passing a small amount of urine, excreting dry

what is the presence of specific feature which enable a plant order an animal too love in a particular habitat called adaptation.

Rats living in desert area are known as kangaroo rats.They have the following adaptations to live in deserts:
1. The front feet of Kangaroo rats are smaller to handle the food while their back feet are very large in order to leap quickly from the predators.
2. They have sharp claws for digging burrows.
Snakes have the following adaptations to live in deserts:
1. Their body mechanisms have evolved in such a way that they need very little water to survive in desert area where water is mostly scarce. Also they do not need food on daily basis.
2. The body colour of many desert snakes mimics the colour of desert sand. Hence they are less visible to their predators.

Snow accumulates on branches and leaves or needles when there is high snowfall.  The conical shape of conifer trees (mountain) prevents as much accumulation of snow as there would be on a wider shaped tree.  The conical shape of the tree also helps to get the snow to fall off the tree quickly and to get the sunlight

The grassland is a place where very few trees or places are available for an animal to hide. Let us take example of a cheetah and a deer to understand the importance of speed for survival in the grassland. The cheetah is the fastest animal on earth. The deer is also very fast, but not as fast as a cheetah. But a cheetah does not have stamina to run long distances and it easily gets tired. If a cheetah is able to catch a deer in a short span of time, it gets food and can live for another day. Many a times, a cheetah dies after running several short sprints in the pursuit of a deer. A deer, on the other hand, can run long distances. If it is able to run quickly so as not to be caught by a cheetah it can live for another day. The examples of these two animals show the importance of speed for survival in the grasslands.

Some of the adaptations which help the desert plants to cope in a dry desert are:

1. The leaves of the desert plants are either absent or are very small or may be present in the form of spines to reduce the loss of water through transpiration.
2. In desert plants, the spines or stems are modified to perform the function of photosynthesis.

Penguins have to keep high body temperatures to remain active. They have thick skin and lots of fat (blubber) under their skin to keep warm in cold weather.

They also huddle together with their friends to keep warm. Emperor penguins have developed a social behaviour that when it gets cold, they huddle together in groups that may comprise several thousand penguins.

The dark coloured feathers of a penguin's back surface absorb heat from the sun, so helping them to warm up too.

The deer is a herbivorous animal which eats only plants. Its special features which help it to survive in grasslands are as follows:

1. It has eyes on the sides of its head which enable it to see in all directions at the same time and helps it to see animals like lion which kill it.
2. It has big ears for hearing which helps it to protect it from its predator animals.
3. It is a fast and agile animal which helps it to run away from the predators.
4. It has brown colour which helps it to hide in dry grasslands without being noticed by the predators like lion.