How are genes passed from parents to children?

When a child is born, people often gather together to discuss whether the child has eyes like his father and mouth like his mother... We know that genetics plays a role in this, but few people know how genetics actually occurs. Today, the blogger will talk to you about how parents pass genes to their children and the currently known genetic laws of appearance.

First of all, we need to know that all of our human genetic information is stored in 23 pairs of chromosomes, of which the first 22 pairs of chromosomes are the same in men and women, and we call them autosomes. The 23rd pair of chromosomes is special, and it determines the gender difference of a person. Women have two X chromosomes, and men have one X chromosome and one Y chromosome.

When a couple gives birth to a baby, the egg from the mother and the sperm from the father only randomly carry half of their chromosomes (23). When the egg and sperm combine, their chromosomes combine to form a set of chromosomes for the child (23 pairs). Therefore, half of the child's DNA is the same as his mother's, and the other half is the same as his father's, which is why the child looks like his father and mother.

So the question is, can couples who are planning to have a baby predict what their baby will look like by comparing some genetic patterns of physical features?

You know what, this is really possible.

color

Usually, a child's skin color will be between the skin colors of his parents. If both parents have fair skin, the child's skin color will most likely be fair. If one parent has dark skin and the other has fair skin, the child may have a "neutral" skin color.

Eye

Compared with small eyes, big eyes are easier to show, so as long as one of the parents has big eyes, the probability of the child having big eyes will be higher. In addition, double eyelids are also easier to show than single eyelids, so if one of the parents has double eyelids, the probability of the child having double eyelids will also be higher.

nose

As for the nose, a straight nose is a phenotype that is more likely to appear than a short and collapsed nose. As long as one of the parents has a high nose, the child is more likely to have a high nose.

ear

Big ears are a phenotype that is easier to show than small ears. As long as one of the parents has big ears, the child is more likely to have a pair of big ears.

Lips

Thin upper lip and bulging lower lip are phenotypes that are more easily manifested. If one of the parents has the above characteristics, the probability of inheriting them to the child will be relatively high.

As for the saying that "girls look more like their fathers and boys look more like their mothers", although it is widely circulated, it does not have much scientific basis. Because the probability of a child inheriting the genes that determine facial features from both parents is the same and random, the saying that one parent has a greater influence on the child's facial features is actually not scientific.

The above is the secret of how parents pass on genes to their children. If readers have other topics of interest, they can raise them in the comment section. The blogger will answer them one by one after checking the information.

References:

1. https://medlineplus.gov/genetics/

2. The original materials of some pictures are provided by Servier Medical Art (http://www.servier.com). Please indicate the source when reprinting.