Category Science

What do we mean by food chain?

Food Chain

A field of green grass waves in the wind. A furry rabbit hops by and nibbles the grass. As the rabbit scurries around, an owl perches overhead. The owl swoops down, grabs the rabbit, and flies away to eat it. When it has eaten its fill, the owl leaves part of the rabbit’s body in another field of grass. The rabbit’s body feeds the soil.

It may seem cruel that animals kill and eat one another. But this is just one way in which wild creatures help each other and keep nature in balance. The grass, the rabbit and the owl are part of an important system in nature called a food chain.

All food chains begin with sunlight. Sunlight provides food for plants. Plants are the primary producers in a food chain. They use sunlight, water, and air to produce food to live and grow.

Animals that eat plants are another link in the food chain. They are consumers. Animals that eat the plant-eating animals are also consumers. The rabbit and the owl are consumers.

Tiny living things called decomposers are also part of the food chain. They break down dead plants and animals into parts. These parts nourish the soil in which the plants grow.

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What is the seasonal movement of animals?

Animals on the Move

When the cold days of winter come, many animals find it hard to find food. So they fly, march, scamper, or swim to warmer places. When spring comes, they fly, march, scamper, and swim back. This movement from place to place as the seasons change is called migration.

Barn swallows, monarch butterflies, ladybirds, caribou, whales, salmon, and lemmings are just a few of the animals that migrate.

When birds migrate, they often fly great distances. Sometimes they cross oceans and continents. In spring, they migrate back. Sometimes they return to the same nests they used the summer before.

In winter, caribou leave their summer home in northern North America and begin dangerous journey southwards in large herds. The following spring they journey northwards again.

Lemmings are small mammals that live in northern Europe. They migrate sometimes, too. When there is a lot of food, lemmings have many young. When the food runs out, they migrate. Sometimes they travel along roads and through towns looking for food.

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What is winter sleep in animals?

Sleeping Through Winter

Every autumn, a woodchuck eats large amounts of food, curls up into a ball, and goes to sleep in its underground home. But the woodchuck’s sleep isn’t like your sleep. The woodchuck’s heart and breathing slow down and nearly stop. Its body changes. Most of the time, the woodchuck’s body is warm because it is a warm-blooded animal. But the woodchuck’s body grows cold before it goes into its long winter sleep. As it sleeps, its body lives off the energy from the extra food it ate in autumn.

The woodchuck’s sleep is called hibernation. Ground squirrels, bats, hamsters, hedgehogs, and other warm-blooded animals also hibernate.

Snakes, turtles, frogs, and toads hibernate in a different way. A snake is cold-blooded. Its body is just as warm or as cold as the air around it. So when the weather grows colder, a snake’s body grows colder. The snake tries to get warm by crawling into a hole. But as the weather becomes colder, the snake’s body becomes cold and stiff. Its heart and breathing nearly stop.

When spring comes, the woodchucks and other warm-blooded animals wake up. The snakes warm up, too, and crawl out of their holes. The world is alive again!

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What are gregarious locusts?

Are you thinking of these insects being particularly chatty? Well, you may not be off the mark. Yes, gregarious locusts are sociable. But they also exhibit a few other characteristics when they are gregarious. Let’s find out more about this.

What are locusts?

Locusts are insects that belong to the grasshopper family, and so, look a lot like grasshoppers. But there are a few crucial differences between them. Among those is the ability of locusts to fly long distances and also invade fields as swans, causing unimaginable damage to agricultural crops. Remember locust invasion in several parts of Africa and India in 2020, reported widely the media? However, locusts are solitary creatures just like grasshoppers, and they come together as swarms only when they are gregarious. Gregarious is a phase that occurs during a locust’s lifecycle.

When do they become gregarious?

During the dry season when there’s not much vegetation around, locusts are forced to come together on small patches of land that has a little vegetation, When that happens, the chemical serotonin gets released in their body. With this they reach the gregarious phase, during which they are sociable. According to National Geographic “Locusts can even change color and body shape when they move into this phase. Their endurance increases and even their brains get larger.” Soon, when it rains, they multiply in large numbers, the place becomes even more crowded, and they start invading agricultural lands in swarms. Reports suggest that the phase is triggered by the need for food.

There are several varieties of locusts that take over large areas of agricultural lands. However, the desert locust is the most dreaded for its country crossing abilities and for polishing off tens of thousands of acres of vegetation.

 

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What are seagrass meadows?

We all know what a meadow is. But most of us wouldn’t know they exist on the seafloor too. Seagrass meadows are among the world’s least known ecosystems. Yet these underwater gardens are crucial to our survival – they are among the most important carbon reservoirs on the planet

Seagrass is a flowering aquatic plant closely related to the flowering plants on land. Seagrasses have long green, grass-like leaves, and are found in shallow salty and brackish waters in many parts of the world

Seagrass meadows support a wide range of marine species such as fish, turtle and dugong. They help prevent beach erosion and mitigate the impact of destructive storm surges. They absorb CO2 and exude oxygen. They also clean the ocean by soaking up polluting nutrients and improve water quality. Recently, scientists have found that certain species of seagrass also capture plastic debris.

What are Neptune balls?

Posidonia oceanica is a type of seagrass found in the Mediterranean waters. When blades of P. oceanica fall or break off their fibres can form tangled masses in the shape of a rugby ball by the swirl of ocean currents. Called Neptune balls, these balls look like brown clumps of steel wool. And researchers have found that these Neptune balls, as they fomu have a knack for trapping small fragments of plastic and then wash ashore during atoms.

By analysing loose leaves and Neptune balls on four Spanish beaches, researchers found plastic pellets, microbeads and polyester fibres from clothes entangled in half of them. Up to 613 and 1,470 items per kg were found in loose leaves and Neptune balls, respectively.

Scientists who were part of this study estimate that the seagrass balls may collect up to 867 million bits of plastic in the Mediterranean annually.

And that’s one more reason to save the seagrass ecosystem from destruction from habitat loss, pollution, coastal construction and overfishing.

 

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How hot or cold are other planets?

While we experience Earth’s many weather conditions each year, let’s see how the weather is on the remaining seven planets.

Mercury

Due to its closeness to the Sun the planet goes through extreme temperatures. In the

daytime, the Sun appears three times larger and over 10 times brighter than on Earth. This pushes temperatures to nearly 800 degrees Fahrenheit. And since there is no atmosphere in Mercury, the daytime heat cannot be trapped. Hence, temperatures can drop as low as 300 degrees Fahrenheit during night time

Venus

While Venus is farther away from the Sun than Mercury, it is the hottest planet in the solar system. This is because Venus is covered by a thick atmosphere of carbon dioxide and clouds made of sulphuric acid. Together, these act like a greenhouse, trapping heat and warming the planet. On average, temperature on Venus can reach as high as 847 degrees Fahrenheit

Mars

Mars weather is the closest to Earth’s. Daytime temperatures on the planet can be close to Winter temperatures on Earth, reaching as high as 32 degrees Fahrenheit. However since it has a thin atmosphere, night temperatures can be as low as -200 degrees Fahrenheit

Jupiter

Since it is far away from the Sun, the planet is only slightly heated up by the star. Jupiter gets most of its heat from the inside of the planet. The temperature of the planet varies in the layers of Jupiter’s atmosphere. On average, Jupiter’s temperature is -234 degrees Fahrenheit.

However, closer to its core, the temperature can go up to 43,000 degrees Fahrenheit!

Saturn

Saturn is really far away from the Sun about 1.4 billion km away Hence, the planet has relatively freezing temperatures throughout which averages at -285 degrees Fahrenheit.

Uranus

The planet is known as an ice giant, and truly so. Is temperature is about 360 degrees Fahrenheit. Due to Uranus being tilted on its own axis, it also experiences different seasons like Earth.

Neptune

Neptune is the farthest planet in the solar system. It is about 3.7 billion km away from the Sun. While that would make it a freezing planet, its temperature is the same as Uranus (-360 degrees Fahrenheit). It is still a mystery to scientists as to why this is so.

 

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