General Science- 2

1. Why are people fair and black?

Answer: Specific genes are responsible for the color of human skin. In addition, human skin contains a pigment called melanin. If it is too much, people are usually black and if it is too little, the skin color is pale.

2. Who is responsible for giving birth to a daughter?

Answer: Whether the child is a boy or a girl depends on the man. A woman's body has chromosomes X and X. A man has X and Y chromosomes in his body.

If a woman's X chromosome coincides with a man's X chromosome, the child will be a girl. And if a woman's Y chromosome is combined with a man's Y chromosome, then the child will be a boy.

Since the two chromosomes that a woman has are both X so she has no choice.

So it can be said that whether the child is a girl or a boy depends entirely on the male chromosome. And for this reason, men are responsible for giving birth to daughters.

3. What are allergies?

Answer: Some people can easily eat any special food. But many cannot eat it for sensitivity. If he eats it, inflammation, gout, skin disease, etc. can be seen in his body. An allergy is a physical problem caused by a person's sensitivity to any food.

4. Why is an extra X-ray harmful to the body?

Answer: X-rays are high-vibration rays. At the same time overuse tends to do some harm. When it enters the body, the surrounding cells are damaged and sometimes die. That is why extra X-rays are harmful to the body.

5. Why do dead bodies float in water?

Answer: According to Archimedes' law of buoyancy, when an object is partially or completely submerged in water, that object removes water of its equivalent volume. If the weight of the removed water is less than the weight of the object, the object is submerged in water. If it is equal, it floats in the submerged state, that is, it remains stationary wherever it is kept. And if the weight of the object is less than the weight of the removed water, then the object floats in the water. Usually, when the density of an object is less than the density of water, the object floats in water.

6. What is coral?

Answer: Coral is the skeleton of a type of marine animal. The skeletons of these animals are formed on the outside of their body which protects the weight of the whole body of the animal. These animals look like a small tube with one mouth closed with many tusks in the closed mouth. As they grow, so does the skeleton.

These marine creatures emit a lime-like substance from their bodies which forms the skeleton.

This skeleton is formed in the shape of a cup below and around the body of the animal. They first attach themselves to a prepared piece underwater and begin to grow. They give birth to twins like small flowers from their own bodies. When the big animal dies, that small animal stays in the skeleton and creates new animals. In this way, a settlement of millions of corals was formed.

These corals are arranged layer by layer in the sea, creating coral islands. Corals are found mainly in tropical warm waters of the Pacific Ocean, Indian Ocean, and the Mediterranean. St. Martin's Island in the Bay of Bengal, Bangladesh is a coral island. Corals also come in different colors for different substances in seawater. After rubbing and smoothing, the coral starts to shine. Mainly used in making jewelry and as showpieces.

7. Which is the deadliest animal in the world?

Answer: The world's deadliest and most dangerous creature belongs to the genus Coelenterata. Its name is Sea Wasp or Sea Wamp. This is a type of jellyfish called Chirnex flaccid. There are innumerable slender tentacles or trunks in their body. There are thousands of microscopic cells on these trunks. With the slightest friction of these trunks, any animal falls to its death in five minutes.

8. Why do tears come out when you cry?

Answer: Each eye has a type of gland called the lacrimal gland. Some of the ducts from this gland are exposed in the eyelids. From the upper leaf again some ducts are exposed to the surface of the eye. It is through these ducts that water comes out of the lacrimal glands. When we blink, fluid or water comes out through the mouth of that duct and keeps the eyes moist and prevents them from drying out. On the other hand, when we are in trouble, that news produces tears through reflex action. In fact, when we cry, more fluid is released through the ducts. This is called tears. Sometimes tears come out even if you smile a lot. This is because the muscles contract the lacrimal glands during laughter. As a result, tears come out. Moreover, if smoke enters the eye or the volatile substance of onion enters, a lot of liquid comes out.

9. Why is the sound heard farther away at night than during the day?

Answer: The air surface adjacent to the night surface is cool and heavy and the upper air layer is relatively warm and light. Therefore, as the sound rises above the surface, it gradually enters the light air layer from the heavy air layer and gradually bends downwards according to the formula of refraction. In this way, the sound of one of the upper air levels is not reflected at one time but is fully reflected back to the surface. Due to this, distant sounds can be heard at night.

On the other hand, during the day the lower air is lighter and warmer and the upper air is relatively cooler and heavier so that as it ascends, it gradually bends upwards due to sound recollection. That is why the sound cannot be heard far during the day.

10. Why not fly in the sky and shadow the birds on the ground?
Answer: The sun is a vast source of light in the sky. The ground screen is much smaller than a bird or aircraft barrier source. As a result, the umbra is very small and the penumbra is large. The top of the shadow cone does not touch the ground as the barrier is much higher than the ground. That is, the shadows of birds and planes do not fall on the ground.

11. How do people swim?
Answer: The body and head of the animal are lighter than the volume of water. So they do not have to learn to swim separately.
The human body is lighter than an equal volume of water but the head is heavier in weight. So the body easily floats in the water but the head wants to sink. Swimming is the name of being able to keep the head out of the water by pressing the hands and feet in the water. That is why people have to learn to swim.
For the same reason, the head of a dead person is submerged in water.

12. Why are metal chains usually hung by touching the ground under a petrol truck?
Answer: The charge is caused by the incessant friction of petrol with the body of the container while the truck is running. This charge can gradually increase and create a spark of fire. This can cause a massive explosion in a mixture of gasoline vapor or air. This is why iron chains are hung by touching the ground to transfer the charge generated by friction to the ground.