Why do ugly parents give birth to beautiful children?

Children's physical characteristics are determined by many pairs of genes from their parents, in which more beautiful children may be due to inheriting recessive genes.

Many people think that their children should look like their parents. However, many children have different looks. Sometimes the parents are beautiful but their children are not good-looking. On the contrary, the parents are average or not very attractive but their children are more beautiful than them.

According to Pharmacist I, Master of Testing Do Ba Tung, Head of Microbiology Department, Le Van Thinh Hospital (HCMC), there are two types of genes: dominant genes and recessive genes. Dominant genes are often expressed while recessive genes are not expressed. This means that parents carry recessive genes but they do not show up in physical characteristics such as hair color, skin color or body shape... Children born with different looks from their parents (uglier or more beautiful) are due to inheriting recessive genes from their parents. This recessive gene can determine whether a physical characteristic is uglier or more beautiful.

"For example, if both parents have naturally straight hair (expressed gene) but their child has curly hair, or if both parents have black-brown eyes but their child has light brown eyes, it is because the child inherits a recessive gene that determines these characteristics," said Master Tung.

A recessive gene in the current parent can also appear as a dominant gene in previous generations or people with the same bloodline as the parent. This explains why in some cases, the child does not resemble the parent but has an appearance similar to relatives, for example, grandparents from previous generations, uncles, etc. Because the child inherits this gene.

Illustration of genes from father and mother. Photo: Freepik — Illustration of genes from father and mother. Photo: *Freepik*

Humans have 46 chromosomes, divided into 23 pairs. Of these, 22 pairs are autosomes and the remaining pair X, Y are sex chromosomes. The type of autosome determines height, hair color, skin color, and growth rate. Meanwhile, the sex chromosome determines the gender of the individual. Humans are born with 44 pairs of autosomes from their father and mother.

Chromosomes are the genetic material in cells, but genes contain the genetic information that determines physical characteristics. Each chromosome carries a different number of genes. Some chromosomes carry up to 800-900 genes like the X chromosome, but some chromosomes carry a "poor" number of genes, only a few dozen, like the Y chromosome (60-72 genes).

Master Do Ba Tung said that genetic characteristics such as height, hair color, skin color, body shape, IQ, personality, behavior... are determined by many pairs of genes.

For example, parents have black-brown hair color genes, and their current hair color is brown. A child has a 50% chance of having brown hair (like the parents) if one parent gives the child black hair genes and the other gives brown hair genes. A child has a 25% chance of having brown hair (like the parents) if both parents give brown hair genes. A child has a 25% chance of having black hair (not like the parents) if the parents give black hair genes.

Even siblings can receive different pairs of genes from their parents, resulting in different appearances or some dissimilar characteristics. In addition to genetic factors, each person's physique, height, personality, and intelligence are also affected by non-genetic factors, which are the environment. Therefore, some children grow up to have very different features from their parents.

Mai Cat

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