What is genetics?

Genetics is the study of genes. Its purpose is to try to explain what genes are and how they work. The function of genes can be considered as a feature that organisms inherit from their distant ancestors. For example, genes are usually the reason why children look like their parents. One of the directions of genetic exploration is to determine which characteristics can be inherited and explain how these characteristics are passed down from generation to generation.

In genetics, biological characteristics are usually called traits. I am afraid that the traits that we can easily understand should be biological markers-such as the color of the human eye, height and thinness, etc. But there are many other traits, including growth and reproduction mode, psychological characteristics, social behavior, disease resistance and so on. These characteristics are usually inherited, as China said, "No pains, no gains". However, some traits may vary from person to person due to environmental changes. For example, a tall son may be short because of malnutrition during his growing period, although it is very likely that he actually inherited a gene that can grow very tall. Under the joint influence of genes and environment, it will be very complicated to clarify the characteristics of an individual. For example, the probability of a person getting cancer or heart disease depends not only on his family history, but also on his quality of life. This explains why some people get lung cancer if they don't smoke, and some people can live for a long time if they smoke all their lives.

Genetic information is mainly carried by a long molecular chain called DNA. By copying this DNA chain, the previous generation of organisms can pass on their traits to the next generation. We can understand DNA as all programs installed in a computer, and biology is a very special computer, which can grow and run according to this program. A gene is a piece of DNA with a certain function, just like a program. If QQ or MSN, which we are familiar with, is used to communicate with others through the Internet, then the gene TRPV 1 is used to make spicy sensory components.

It should be noted that the actual content and form of the specific gene we are talking about may be different. For example, a gene is used to describe the color of hair, or when hair grows, this gene will produce various pigments and attach to hair. For Han people, their genes usually produce black hair. However, the content of the same gene in an individual is different from that in most people, which leads to the whitening of hair. The content of genes is composed of hundreds or even hundreds of thousands of things called base pairs. Some of these base pairs may mutate, resulting in differences in the content of the same gene among organisms. This mutation is usually a random event, which produces new characters and even leads to an important part of biological evolution.