1. How do fish know who they are?
Fish can't see themselves, so they probably don't know what they look like. But they are still able to recognize other members of their species and join the fish.
The sense of smell is an important sensation for fish. Many fish release potent pheromones that tell other fish not only if they belong to the same species, but also if they are siblings.
Recent studies of zebrafish (guinea pigs in the fish world) have also shown that some fish may discover their own species by the way they move.
When a zebrafish is shown a computer screen, there is a black dot on the screen that is constantly moving, which is characteristic of the zebrafish's swimming style, and it will swim with the black dot for hours.
Even fish that grow up in isolation follow the spots, suggesting that this behavior of zebrafish is innate, and that other species may be the same.
2. What connects protons and neutrons in the nucleus?
All the protons are positively charged and thus repel each other. So the fact of the existence of atoms shows that there is a force that can overcome this repulsive force.
It is called a strong interaction, and its origin lies in the particles that lurk in protons and neutrons, known as quarks. These particles have a strange form of charge that sticks them inside their host particles, and can also seep out to bind protons and neutrons together.
3. How long does it take for caffeine to work?
The study found that the effects of a cup of coffee or a cup of cola were evident after 10 minutes, but the concentration of caffeine in the blood peaked after 45 minutes.
If you take the same dose of caffeine in tablet form, the peak level of caffeine will be the same, but it will take longer to reach the peak – 60 to 75 minutes.
For most people, the amount of caffeine in the body is halved about every six hours. Therefore, 50% of the caffeine contained in afternoon tea will still circulate in your body before bedtime.
4. Why do some people become aggressive after drinking?
Alcohol alters the activity of the frontmost part of the brain (the prefrontal cortex), which is associated with decision-making and self-control, which makes drinkers more impulsive.
This can manifest itself in relatively innocuous ways, such as being more inclined to tell jokes to strangers, or in more dangerous ways, such as driving fast or reacting to provocations.
The decompression effect of alcohol exaggerates the sober character of the drinker. As a result, those who are more likely to get angry and less worried about the consequences are more likely to become aggressive when drunk.
5. Why do dogs chase their tails?
Sometimes, this is a hunting behavior*** In an animal that is too dim, the dog, which is a human hunting partner, sees a tail running away, so it keeps chasing the tail in its eyes. But "tail-gating" can become obsessive.
Bored dogs that don't get enough exercise may use it to grab their owner's attention – even angry attention can be beneficial.
Others, especially terriers, may have inherited this gene. Sometimes, many dogs need to take antidepressants to control their compulsive "tail-chasing" behavior.
In fact, this kind of behavior of cats is more obvious, often like to chase a thing, will your pet be like this? More quirky and welcoming***
6. Why do apples become particularly easy to spoil when they fall?
Cutting or dropping apples can cause separations inside the cells, including the rupture of the storage sac (vacuole), allowing chemicals to mix, oxygen to rush in, and catalyze the reaction.
In particular, chemicals called polyphenols in vacuoles come into contact with an enzyme called polyphenol oxidase, which is found in every cell of apples.
It's this reaction that causes the brown, nasty "melanin" chemical we see on sliced or bruised apples.