Answer:
A dolphin breathes through a single blowhole on the top surface of its head. The blowhole is covered by a muscular flap, which provides a watertight seal.
A dolphin holds its breath while below water.
The dolphin opens its blowhole and begins to exhale just before reaching the surface of the water. To open the blowhole, the dolphin contracts the muscular flap.
Explanation:
Vitamin <u>A</u> is necessary for vision, bone growth, and maintenance of epithelial cells.
We can define vitamins as micronutrients that perform various important functions in the body. Vitamins cannot be synthesized by the body of a person and hence are derived from the diet of a person.
Vitamin A is present in many foods and it is a fat-soluble vitamin. Vitamin A helps the body in various functions such as improving vision, helping the immune system, growth of bones, maintenance of cells etc.
Certain foods contain carotenoids in them. A person's body has the ability to convert these carotenoids into Vitamin A which is then used by the body for various functions. Some preformed sources of Vitamin A include dairy products and eggs.
To learn more about vitamin A, click here:
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Answer:
1. E.coli
2. Intestinal tract
Explanation:
E.coli bacteria are useful to humans when they live in the large intestine of humans. The large intestine is an important digestive structure as it is important for the reabsorption of the nutrients.
The E.coli living in the intestine use the available digested nutrients and synthesises the vitamin B and K which are absorbed and utilised by the human body.
Thus, E.coli and Intestinal tract is correct.
It is any animal that that sheds feathers or fur and it is replaced with a new layer
