These DAV Class 7 Science Notes and DAV Class 7 Science Chapter 13 Notes – Weather, Climate and Adaptation of Animals act as excellent revision resources, particularly in preparation for board exams.
Weather, Climate and Adaptation of Animals Class 7 DAV Notes
→ Weather: The state of atmosphere at a particular time and place with respect to the various elements is called weather.
→ Elements of Weather
- Temperature: The measure of the degree of hotness is called temperature. Temperature varies according to elevation, season, time of the day and latitude.
- Humidity: The measure of the amount of water vapour in the atmosphere is called humidity. Humidity is usually taken in terms of relative humidity which is expressed as percentage.
- Cloudiness: Degree of cloud density at a particular place at a particular time can be termed as cloudiness.
Precipitation: When the droplets from clouds fall on ground it is called precipitation. Rain, drizzle, snow, hail, ice pellets and sleet are various forms of precipitation.
- Wind: The moving air is called wind. Wind speed greatly affects the weather of a place.
- Atmospheric Pressure: Atmospheric pressure is the pressure exerted by air. Atmospheric pressure tends to decrease with altitude.
→ Climate: The dveiage weather in a particular region over a long period of time is called climate. For example; the climate of India is said to be monsoon climate.
→ Climate of India: Climate of India can be divided into four climatic zones, viz. Alpine, Subtropical, Tropical and Arid Zones.
- Alpine Zone: This climate is present at the high altitudes of the Himalayas. This area is snow capped throughout the year.
- Sub-tropical: This zone is present in a major part of northern India. Summers are hot and wet, while winters are cold and dry.
- Topical: This climate zone can be divided into two parts; Tropical Wet and Tropical Dry monsoon. In Tropical Wet climate, temperature is average and rainfall is high. In Tropical Dry climate, rainfall is scarce.
- Arid: This climate zone has high temperature and low rainfall. This type of climate is present in the western part of the country. The temperature in this zone may go up to 50°C.
→ Climate and Adaptation:
→ Adaptation: This is an ability of an animal which makes it suited to its environment. Some examples of adaptation are as follows:
→ Behavioural Adaptation: Moving in large groups is an example of behavioural adaptation. This helps in protecting the members of the group from predators.
→ Structural Adaptation: Polar bear has a thick coat of fur; which is an example of structural adaptation.
→ Polar Regions: The polar regions are very cold and temperature may go down to sub-zero levels. Antarctica, Alaska, Greenland, Finland, Norway and Siberia fall in the polar region. Vegetation is scanty in this region.
→ Polar Bear: Polar bears show many adaptations to survive in the polar region. The thick coat of white fur helps in insulating against low temperature. White fur helps the animal in mixing with its background. There is a layer of fat underneath the skin; which also provides insulation. Polar bear has well developed sense of smell. It can smell a fish which may be several feet below the frozen ice. Its front paws help it in swimming.
→ Penguin: Penguin is another animal which is well adapted to polar region. Feathers of penguin are densely packed and thus provide protection against cold. The bones of penguin do not have air spaces. It helps them to sink in water. A layer of fat (blubber) is present beneath the skin. Streamlined body and paddle-like feet help it in swimming.
→ Tropical Rainforests: Tropical rainforests get very high rainfall throughout the year. Due to this, the area is thickly covered with vegetation. Rainforests are home to a wide variety of animals. The Amazon jungle is the world’s largest tropical rainforest. In India, tropical rainforests are found in the Western Ghats and Assam. Adaptations of some of the animals of tropical rainforest are given below:
→ Monkey: The long prehensile tail of monkeys is used for grasping the branches. The long arms and legs help it in swinging from one branch to another.
→ Toucan: Toucan is a bird. Its large and strong beak helps it in picking and eating fruits.
→ Lion tailed Macaque: It has long tail with a tassel at the end. These monkeys use 17 different vocal patterns to communicate. This monkey has cheek pouches. The macaque monkey can store a big amount of food in its cheek pouches.
→ Big Cats: Lion, tiger, leopards, etc. are examples of big cats. Their body is flexible and designed for running, jumping and climbing. They have a well developed night vision; so they can hunt during night.
→ Elephant: Elephant is a large and strong animal. It can uproot a tree with its trunk. The sense of smell is well developed in elephant which helps it in searching for food and water.
→ Meteorology: The science of studying and forecasting climate and weather.
→ Weather: Weather is a short term phenomenon which tells about climatic conditions at a particular time and place.
→ Climate: Climate is a long term phenomenon which tells about long term climatic conditions of a place.
→ Adaptation: The ability of an organism to adjust to its environment.
→ Camouflage: The ability of an animal to mix with its surrounding.
→ Blubber: Thick layer of fat beneath the skin of an animal.
→ Humidity: Relative amount of moisture in air.
→ Rainforest: Forests with evergreen trees which are found in tropical regions.