Appearance, intelligence or disease tendency? What do we inherit from our mother’s genes?

At fertilization, two gametes fuse – male (sperm) and female (egg). Each of them contains 23 chromosomes that carry genetic information. What a human will be like, 50 percent. are determined by genes, and in 50 percent environmental factors. The zygote has 23 pairs of chromosomes that contain genetic information. What are the characteristics of DNA? Do we inherit only physical traits from our parents, or are we predispositions and inclinations?

1. Scientists in the nineteenth century established that one of the features inherited from the mother is the level of intelligence
2. It is also possible to inherit personality traits and even a tendency to certain mental illnesses
3. What about looks and things like eye and hair color? Here, the issue is a bit more complicated
4. More information can be found on the Onet homepage

What chromosomes determine a child’s gender?

The zygote consists of 22 pairs of autosomal chromosomes and the 1st pair of sex chromosomes – in men marked as XY and in women XX. If the male gamete containing the X sex chromosome at the time of fertilization joins the female cell with the X sex chromosome, we obtain the zygote XX. This creates a diploid cell from which the female embryo will develop.

When the male gamete contains the Y chromosome, fertilization produces a zygote with the XY sex chromosomes, and the male embryo develops from it. From the moment of fertilization, the zygote has a full set of chromosomes (46). The sex chromosome pair determines the sex of the baby.

What do we inherit from our mother?

Women inherit two X chromosomes from their parents, but only one of them is genetically active. This state of affairs leads to the fact that females are more often carriers of diseases for which genes located on the genetic system marked as X are responsible and are less likely to suffer from them than men. Sons have one X chromosome (from their mothers), therefore the genes linked to them show up more often.

If a gene on the X chromosome is responsible for some developmental abnormality, there is a good chance that a man who receives it from his mother will develop the defect. In the case of girls, it can be assumed that a defective gene present in one X chromosome will remain inactive, and a healthy one, located in the X gene structure inherited from the other parent, will turn out to be dominant.

Already in the nineteenth century, scientists from the University of Cambridge reported the results of experiments, which showed that one of the traits inherited from the mother is intelligence. It is said that the genes responsible for this trait are largely located on the X chromosome. Boys receive X chromosomes only from their mothers, and girls inherit genes located on the X chromosomes from both parents.

It is highly likely that daughters will mature as sexually as their mothers. It is not uncommon for them to start menstruating at the same age as their parents. They may also enter the menopause at a similar time.

Do girls inherit more from their mother and boys from their father?

It is believed that 50 percent. traits are inherited from the father, the same as many from the mother. Not really, because there is another type of DNA that is passed only by the mother, contained in the mitochondria: These small genes embedded in cells are involved in cell respiration and energy production, among other things. What happens to sperm mitochondria? They are destroyed during fertilization, possibly by autophagy, a mechanism discovered in some animals such as nematodes (worms): enzymes in the embryo digest the mitochondria. Where does this phenomenon come from? According to biologist Vincent Gala (CNRS), there is a major hypothesis: “The mitochondrial genome of sperm tends to mutate. Destroying it would therefore prevent the irregularity from being passed on to the offspring. ‘

Research by Scottish specialists published in the magazine “Sleepe Medicine” confirm that we inherit our night habits from our mother. In addition, we have a chance to inherit a slower aging from the mother, thanks to the aforementioned mitochondria. In this regard, women should watch their parent go through the menopause. It is highly probable, as the English scientists from the Institute of Cancer Research in London prove, that the same processes will take place in their bodies. The way people experience going through menopause is hereditary.

The genetic information stored in DNA is inherited through sexual reproduction. Regardless of the child’s gender, it inherits the same gene pool from the mother and father. What traits show up in an offspring depends on whether the genes responsible for specific body components are dominant or recessive. After mixing the genetic material of the mother and father, their offspring will show traits for which the dominant gene is responsible. The properties assigned to recessive genes will only emerge when the child receives the same recessive alleles from both parents.

The rest of the text below the video.

Which features of appearance are dominant and which are recessive?

Among the recessive features that are revealed only when two recessive alleles are passed on in the genetic material, there are, for example:

1. fair or red hair
2. bent thumb,
3. square face shape,
4. round eye shape,
5. Rh- blood group,
6. no tendency to baldness,
7. blue eye color,
8. laying the right thumb on the left while folding the hands.

Do we inherit memories?

In the case of people who experienced a very strong trauma, it happened that it was somehow written in their genes. Experiments in mice to investigate intergenerational epigenetic inheritance showed that it is possible to inherit a conditioned reflex.

Scientists conducting the experiment combined the use of an olfactory stimulus (spraying acetophenone) with light electric shocks. The effect of this action was a stress response in mice after exposure to the olfactory stimulus alone. Interestingly, fertilization of mice (by the method of vitro) genetic material collected from individuals involved in the experiment, resulted in the birth of animals that also experienced a stress reaction in response to the smell of acetophenone.

Introversion and extroversion can be inherited

Genetics scientists have discovered genes responsible for introversion and extroversion. The results of research conducted on identical and fraternal twins show that even in the case of similar experiences and the way of upbringing, the perception of the world and personality traits may be shaped differently in each of the siblings.

It is also interesting that genes to which personality traits are assigned are also responsible for such mental disorders such as depression, attention deficit hyperactivity disorder and anxiety states. The type of psychopathic personality can also be inherited, which is undoubtedly related to the differences in the structure and activity of specific areas of the brain.

Inheritance of diseases

Mutations of single genes can be responsible for genetic diseases. Autosomal inheritance is also possible – dominant or recessive, and X-linked dominant or recessive inheritance. autosomal dominant genetic diseases include, for example, Marfan’s syndrome, Huntington’s disease, achondroplasia and familial hypercholesterolaemia.

W autosomal recessive inheritance can be passed on to offspring, among others: cystic fibrosis, phenylketonuria, homocystinuria, haemochromatosis and lactose intolerance.

In the case of X-linked recessive inheritance, the incidence of genetic disease can be observed mainly in boys. This is because male children inherit one X chromosome (from the mother) and it is then the active chromosome. Female children receive two X chromosomes (from their mother and father). If one of them contains a recessive gene responsible for a disease or defect, the most likely in this case will be an active chromosome that does not contain the defective gene. Diseases inherited in this way include hemophilia A and B, and Duchenne muscular dystrophy.

Diseases due to X-linked dominant inheritance occur with the same frequency in daughters and sons. In such cases, heterozygous women will often develop a milder form of the disease than heterozygous men for whom inheriting the defective gene may be associated with severe disease or even death. The genetic diseases inherited in this way include, for example, Bloch-Sulzberger syndrome, Rett syndrome and hypophosphatemic rickets.

What’s in the genes?

According to some researchers, inherited features include: way of moving, favorite position during sleep, and even problems with insomnia. People with a family history of obesity, diabetes or hypertension should not underestimate the inherited predispositions. It happens that it is also inherited, for example, a tendency to the formation of varicose veins, weakened blood vessels, multiple birthmarks or the risk of developing cancer. Women whose mothers have had uterine fibroids or endometriosis may also experience these types of problems.

Although geneticists and epigenetics have been dealing with the issue of inheritance for many years, the subject of their research is still not fully understood. However, doctors are able to recognize some genetic diseases already in the prenatal period, and the genetic tests performed provide a lot of information about the predisposition to developing various diseases.

More recent research on inheritance focuses on explaining why not only physical traits are passed on between generations, but also personality traits, predispositions to be successful in sport, artistic talents, and even a tendency to addiction or mental disorders. It should not be forgotten that genes determine human features only in 50%. People themselves have a huge influence on who they become.

We encourage you to listen to the latest episode of the RESET podcast. This time we devote it to ecology. How to be eco and not go crazy? How can we care for our planet on a daily basis? What and how to eat? You will hear about this and many other topics related to ecology in the new episode of our podcast.