Category Science

Who is known as the father of vaccinology?

Edward Jenner was an English physician and scientist who pioneered the concept of vaccines including creating the smallpox vaccine, the world’s first vaccine. The terms vaccine and vaccination are derived from Variolae vaccinae (smallpox of the cow), the term devised by Jenner to denote cowpox. He used it in 1798 in the long title of his Inquiry into the Variolae vaccinae known as the Cow Pox, in which he described the protective effect of cowpox against smallpox.

He still remembered the Bristol milkmaid’s remark and acquired the reputation of a bore because of his constant harping on cowpox and its preventive use. Eventually, and totally unethically, he took lymph from a pustule on the hand of a milkmaid and inoculated a healthy child, who developed cowpox in the normal fashion but proved immune to subsequent inoculation with smallpox. Both the medical profession and the Royal Society were hostile to these unorthodox practices so Jenner published his observations in 1798 and travelled to London to publicize them. His reception was so unenthusiastic that he returned to Gloucestershire leaving some lymph with Mr Cline, a surgeon at St Thomas’s Hospital. Cline used it to inoculate a child who also proved immune to a later attempt at smallpox inoculation and this popularized the practice.

 

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What is significance of Bird Feathers?

You know that all birds have feathers. Some feathers are quite beautiful. But what are feathers for? Feathers help most birds to fly, but they are important for other reasons, too.

In cold weather, a bird’s feathers make a warm winter coat. The bird fluffs up its feathers to keep its body warm. For some birds, waterproof feathers act like a raincoat. These birds can swim and dive without getting too wet and sinking.

The colours of feathers can be important, too. Bright colours help some birds attract mates. Other colours make birds blend in with their habitat so they are hard to see. Then hungry enemies won’t notice them.

All birds have wings. Wings are for flying, of course, and most birds can fly.

A bird’s wings are thin and very light. They are nothing but a few little bones and small muscles covered with thin skin and feathers.

Bird wings aren’t all the same, however. The kind of wings a bird has depends mainly on the bird’s way of life.

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How does a baby bird get out of the egg?

Inside an egg, a tiny baby bird is curled up in a ball. Its head is bigger than its body. Its eyes are closed. All the food it needs is inside the egg. The baby bird has grown so much that it fills up the egg. It is ready to hatch.

The baby bird begins to move inside the egg. The eggshell cracks, the crack grows bigger, and bits of the shell fall off. Soon there is a big hole. The baby bird wiggles through the hole. A new life has begun.

When some kinds of birds hatch, they are helpless. Their eyes are still closed and they have no feathers. They can’t stand on their tiny, weak legs. Birds such as robins and nuthatches are helpless for weeks after they hatch. They need their mothers to feed them and keep them warm. But other kinds of birds can see, walk, and hunt for food soon after they hatch, even though they cannot fly yet. Two days after hatching, a duckling can run, swim, and find food.

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Why do different birds make different kinds of nests?

It’s springtime. A bird flies by with a piece of red string in its mouth. Soon it flies by again with a twig. What is it doing? The bird is getting ready to build its nest. The nest is where the mother bird will lay her eggs. After the chicks hatch, they will stay in the nest until they grow up.

Different kinds of birds build different kinds of nests. Many birds make nests in trees. Some of these are layers of twigs piled together. Others are like bowls made of mud and grass. Nests can also be holes in tree trunks, or hanging pouches or sacs made of woven twigs and grass.

Some water birds make nests that float on water. They make the nests out of weeds and sticks and fasten them to rushes.

Some birds don’t make nests at all. Some sea birds lay their eggs on a ledge on the side of a cliff. Other birds lay their eggs in holes in the ground. And some birds lay their eggs in the nests of other birds.

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What are the largest sea mammals?

The Largest Mammals

A humpback whale swims near the top of the water. From time to time, it comes up for fresh air, filling its lungs. Then the whale dives down again. A few minutes later, it surfaces once more, and whoosh! the whale blows used air through the blowhole on top of its head. It breathes in again and dives.

Whales live in the water and look like fish, but they are really mammals. They are warm-blooded and feed their babies with mother’s milk. They don’t have gills like fish – they have lungs. That’s why they must come to the surface for air.

Big whales eat big things, right? Well, not all whales do. The throats of many whales are too small to swallow anything bigger than an orange! And many whales have no teeth. Baleen whales, such as right whales, gray whales, and rorquals, strain food from the water through hundreds of thin plates in their mouths. These whales eat plankton, which is made up of tiny plants and animals.

Toothed whales include sperm whales, belugas, and narwhals; dolphins and porpoises; and killer whales. These whales are meat eaters. Favorite meals include squid, crabs, lobsters, sharks, cod, and skates.

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