All information about a person - his appearance, character, talents and inclinations - is contained in the DNA strand, which is present in the nucleus of every cell in the body. The data is encoded in 46 chromosomes: a person inherits 23 chromosomes from his father and mother. They contain 50,000-100,000 genes that determine such human features as skin color, eyes, hair, character, etc.
What is inherited and how?
Most genes have two variations, called alleles, which can be dominant or recessive. If there are different genes in a pair, then one of them “wins”. It is called dominant, while the “repressed” gene is called recessive. When both the father and the mother have a recessive gene, then it is not only inherited by the child, but also manifests itself in him.
Dominant genes are:
- for dark eye color;
- dark coarse curly hair;
- full lips;
- swarthy skin;
- big nose with a hump;
- wide chin.
Recessive genes that are inherited carry such features of appearance as:
- light eyes;
- light soft straight hair;
- thin lips;
- bright skin;
- narrow nose with small nostrils;
- narrow chin.
For example, light eye color is a mutation of the OCA2 gene, blue and green tint is provided by the EYCL1 gene on chromosome 19, and brown is EYCL2. In general, eye color is determined by genes such as OCA2, SLC24A4, TYR.
Character traits and habits that are inherited
Genes received from parents determine not only the appearance of the child. Scientists believe that intellectual abilities can also be inherited. Of course, the upbringing and education of the child plays an important role in this. Artistic taste, creativity, musicality and other qualities also pass from parents to children. What else is inherited: temperament, facial expressions, voice timbre.
Unfortunately, inheritance is not only about positive traits character. It is believed that a baby can inherit alcoholism, aggression, phobias, fears, and suicidal tendencies from mom and dad. Proper upbringing, a favorable atmosphere in which a child grows up, and parental care make it possible to neutralize negative genetic tendencies.
Health "by inheritance"
More than 3500 human diseases caused by heredity have been described. Scientists know the specific genes "guilty" in the development of the disease, their mutations and types of disorders leading to the development of pathology. Inherited from parents: color blindness, diabetes the first type, vitiligo, hereditary cardiomyopathy, phenylketonuria, bronchial asthma, cystic fibrosis, schizophrenia, etc. Heredity determines a person's metabolism, features of work immune system, level of stress resistance, etc.
How to find out what is inherited?
Modern science and medicine make it possible to obtain information about the genetic makeup of any person. This means that parents can know in advance which genes they can pass on to their child. This is especially true for genetic diseases and abnormalities.
Karyotyping is a study in which a map of human chromosomes is compiled. It allows you to detect rearrangements and anomalies in the chromosome set of parents that can be transmitted to the child. When a couple knows that they can be inherited, they approach the issue of pregnancy planning more responsibly. Knowing about the risks future mom readily undergoes prenatal screening to ensure that there are no abnormalities and genetic disorders in the unborn child.
IN medical genetic center"Genomed" carries out karyotyping and other studies of the chromosome set of parents and the unborn baby. The center also offers non-invasive and invasive prenatal fetal diagnostics.
Genetics is a science not only interesting, but also convenient. Researches of scientists have proved that a lot of things in us do not depend on us, but are inherited. Genes, there's nothing you can do.
dominant and recessive
It's no secret that our appearance is made up of a number of traits that are determined by heredity. You can talk about the color of the skin, hair, eyes, height, physique, and so on.
Most genes have two or more variations, called alleles. They can be dominant and recessive.
Complete dominance of one allele is extremely rare, including due to the indirect influence of other genes. Also, the appearance of the baby is affected by multiple allelism observed in a number of genes.
Therefore, scientists only talk about a higher probability of the appearance in children of external signs caused by the dominant alleles of the parents, but nothing more.
For example, dark hair color is dominant over light hair. If both parents have black or blond hair, then the child will be dark-haired.
Exceptions are possible in rare cases if there were, for example, blonds in the family from both parents. If both parents are owners of blond hair, then the likelihood that the baby will be a brunette increases. Curly hair is more likely to be inherited because it is dominant. As for eye color, dark colors are also strong: black, brown, dark green.
Such features of appearance as dimples on the cheeks or chin dominate. In a union where at least one partner has dimples, they are likely to be passed on to the younger generation. Almost all prominent features of appearance are strong. It can be a big, long nose or a hump on it, protruding ears, thick eyebrows, plump lips.
Will the girl be obedient?
Whether a daughter will become a neat girl who loves dolls, or will grow up like a boy, playing “Cossack robbers”, is largely determined by maternal instinct, which, as it turned out, depends on two genes.
Research conducted by the Human Genom Organization (HUGO) shocked the scientific community when they presented evidence that the instinct of motherhood is transmitted exclusively through the male line. That is why scientists argue that, according to the behavioral model, girls are more likely to be like paternal grandmothers than like birth mothers.
Inherited aggressiveness
Russian scientists in the Human Genome project were tasked with determining whether aggressiveness, irritability, activity and sociability are genetically inherited traits, or are formed in the process of upbringing. We studied the behavior of twin children aged 7 to 12 months and their genetic relationship with the type of behavior of their parents.
It turned out that the first three traits of temperament are hereditary in nature, but sociability is 90% formed in a social environment. For example, if one of the parents is prone to aggression, then with a probability of 94% this will happen again in the baby.
Alpine genes
Genetics can explain not only external signs, but even national characteristics different peoples. So, in the Sherpa genome there is an allele of the EPAS1 gene, which increases the presence of hemoglobin in the blood, which explains their adaptability to life in high mountain conditions. No other nation has this adaptation, but exactly the same allele was found in the genome of Denisovans - people who are neither Neanderthals nor Homo Sapiens. Probably, many millennia ago, Denisovans interbred with the common ancestors of the Chinese and Sherpas. Subsequently, the Chinese living on the plains lost this allele as unnecessary, while the Sherpas retained it.
Genes, sulfur and sweat
Genes are even responsible for how much a person sweats, and what kind of earwax he has. There are two versions of the ABCC11 gene that are common in the human population. Those of us who have at least one of two copies of the dominant version of the gene produce liquid earwax, while those of us who have two copies of the recessive version have solid earwax. Also, the ABCC11 gene is responsible for the production of proteins that remove sweat from the pores in the armpits. People with hard earwax don't sweat like that, so they don't have odor problems or need to wear deodorant all the time.
sleep gene
Dream ordinary person is 7-8 hours a day, however, if there is a mutation in the hDEC2 gene that regulates the sleep-wake cycle, the need for sleep can be reduced to 4 hours. Carriers of this mutation often achieve more in life and career due to extra time.
speech gene
The FOXP2 gene plays an important role in the formation of the speech apparatus in humans. When this was found out, geneticists conducted an experiment to introduce the FOXP2 gene into chimpanzees, in the hope that the monkey would speak. But nothing of the kind happened - the zone responsible for the functions of speech in humans, in chimpanzees, regulates the vestibular apparatus. The ability to climb trees in the course of evolution for the monkey turned out to be much more important than the development of verbal communication skills.
happiness gene
For the past decade, genetics has been struggling to prove that a happy life requires the appropriate genes, or rather, the so-called 5-HTTLPR gene, which is responsible for transporting serotonin (the "hormone of happiness").
In the last century, this theory would have been considered crazy, but today, when the genes responsible for baldness, longevity or falling in love have already been discovered, nothing seems impossible anymore.
To prove their hypothesis, scientists at the London Medical School and School of Economics interviewed several thousand people. As a result, volunteers who had two copies of the happiness gene from both parents turned out to be optimistic and not prone to any kind of depression people. The results of the study were published by Jan-Emmanuel de Neve in the Journal of Human Genetics. At the same time, the scientist stressed that other “happy genes” could soon be found.
Nevertheless, if for some reason you have a bad mood for a long time, you should not rely too much on your body and blame mother nature for “depriving you of happiness”. Scientists argue that human happiness depends on many factors: “If you are unlucky, you lost your job or broke up with loved ones, then this will be a much stronger source of unhappiness, no matter how many genes you have,” said de Neve .
Genes and diseases
Genes also influence which diseases a person may be prone to. In total, about 3500 have been described to date, and for half of them a specific culprit gene has been established, its structure, types of disorders and mutations are known.
Longevity
The longevity gene was discovered by scientists at Harvard Medical School in Massachusetts back in 2001. The longevity gene is actually a sequence of 10 genes that may hold the secret to a long life.
During the implementation of the project, the genes of 137 100-year-old people, their brothers and sisters aged 91 to 109 were studied. All subjects found "chromosome 4", and scientists believe that it contains up to 10 genes that affect health and life expectancy.
These genes, scientists believe, allow their carriers to successfully fight cancer, heart disease and dementia, and some other diseases.
figure type
Genes are also responsible for the type of figure. Thus, a tendency to obesity often occurs in people who have a defect in the FTO gene. This gene disrupts the balance of the "hunger hormone" ghrelin, which leads to a violation of appetite and an innate desire to eat more than necessary. Understanding this process gives hope for the creation of a drug that reduces the concentration of ghrelin in the body.
eye color
It is traditionally believed that eye color is determined by heredity. Light eyes are caused by a mutation in the OCA2 gene. The EYCL1 gene on chromosome 19 is responsible for the blue or green color; for brown - EYCL2; for brown or blue - EYCL3 chromosome 15. In addition, the OCA2, SLC24A4, TYR genes are associated with eye color.
Also in late XIX centuries, there was a hypothesis that human ancestors had exceptionally dark eyes. Hans Eiberg, a contemporary Danish scientist at the University of Copenhagen, has carried out scientific studies confirming and developing this idea. According to research results, the OSA2 gene responsible for light shades of the eyes, whose mutations turn off the standard color, appeared only during the Mesolithic period (10,000-6,000 BC). Hans has been collecting evidence since 1996 and concluded that OCA2 regulates the production of melanin in the body, and any changes in the gene reduce this ability and disrupt its functioning, making the eyes blue.
The professor also claims that all the blue-eyed inhabitants of the Earth have common ancestors, tk. this gene is inherited. However different forms of the same gene, alleles, are always in a state of competition, and the darker color always “wins”, as a result of which parents with blue and brown eyes children will be brown-eyed, and only a blue-eyed couple can have a baby with eyes of cold shades.
Blood type
The blood type of the unborn baby is the most predictable of all hereditary traits. Everything is quite simple. Knowing the blood type of the parents, you can tell what it will be in the child. So, if both partners have 1 blood type, then their baby will have a similar one. With the interaction of 1 and 2, 2 and 2 blood groups, children can inherit one of these two options. Absolutely any blood type is possible in a child whose parents are 2 and 3 groups.
The genes of our ancestors contain many secrets related to our talents, intelligence, beauty and predispositions to various diseases. It turns out that relatives can even give us a tendency to succumb to strong emotions or certain moods. All through epigenetics. What is it about?
For mom or dad? Who do we look more like (not just because of the physical appearance), is recorded in our genetic lineage from the moment of conception. Although we are a mixture of genes from both parents, some features can only be passed on to one of them. They appear depending on the combination in which the genes of a given pair are located.
Every mother and father has double portions of dominant or recessive genes. The child receives a set of 23 chromosomes from the father and 23 from the mother. Each inherited trait is determined by two genes (dominant and recessive). There are many combinations. For example, 2 dominant and 1 recessive genes can be passed on to us, etc.
Dominant genes:
- dark or curly hair
- brown eye color
- Rh + blood type
- hooked nose (probability of inheriting properties 75%).
- protruding ears
- tendency to freckles
- characteristic dimples on the cheeks
recessive genes:
- straight hair or its bright color when it reaches maturity
- blood group Rh-
- blue, relatively small eyes
Intelligence comes from the mother, but the father influences the efficiency of thinking
From a study published in Psychology Spot, it appears that when it comes to intelligence, it is inherited from the mother, not from the father. It has been proven that the genes responsible for intellectual ability are contained in the X chromosome carried by women (the female sex determines the XX chromosomes and the male XY genes). Cambridge professors were the first to prove that the mother's genes make a significant contribution to the development of centers of thought in the child's brain.
In turn, scientists from Glasgow analyzed the results of a study of more than 12 thousand people from 14 to 22 years old and confirmed that the best indicator of intelligence was the IQ of the mother, which can differ by no more than 15% compared to the IQ of her offspring (after reaching maturity ).
Researchers at the University of Ulm in Germany came to similar conclusions, which proved that most of the pathologies associated with cognitive skills are associated with the X chromosome inherited from mothers. Even when it comes to mental disability, this type of disability is more common in men. This happens statistically less frequently in females, which is further evidence of why Mother Nature preferred females to pass on the genes responsible for intelligence to their offspring, increasing the evolutionary chances of survival.
However, anyone who thinks that the father does not affect the mental abilities of the child is mistaken. The latest research findings, published by German scientists in the prestigious Cell Reports, indicate that brain health may be important for children and for generations to come.
Epigenetic inheritance is responsible for the transmission of many characteristics depending on environmental factors or lifestyle of parents. Brain exercises (both physical and mental) are beneficial for parents (both father and mother) and can have a positive impact on their future children. In turn, the RNA molecule contained in sperm and transmitted from paternal DNA, according to researchers, can change the development of the brain of children, improve communication between neurons and cause a cognitive advantage in offspring. Therefore, a father can influence the thinking skills of children, and the better his brain is, the easier it will be for his children to learn and learn information in the future.
Emotions, obesity and even suicidal tendencies
Due to epigenetic inheritance, many characteristics can be passed on to us depending on factors. environment and lifestyle that our parents preferred. Men who are addicted to smoking before puberty most often, for example, have sons who are overweight or obese in the future.
Epigenetics is providing more and more evidence that, from generation to generation, we can pass on not only features such as eating habits and weight, but also tendencies to certain emotions. Mainly due to trauma, intense experiences that are reflected in the cellular memory that our ancestors pass on to us, although genes do not have to be involved.
World-renowned neurologist Michael Mainey of McGill University in Montreal, who has devoted himself to studying the brains of suicide, has been trying for years to determine why suicide is more common in some families. He was able to see that the areas of the suicidal brain responsible for emotions, the genes involved in stress and the weakening of these genes, were associated with psychological immunity and stress management. Interestingly, compared to the brains of accident victims who did not have psychological problems or depressions, etc., there were obvious differences in suicidal minds. Why is this happening?
Trauma can have consequences in later generations
One of the earliest evidence of epigenetic inheritance comes from research conducted by researchers at New York's Mount Sinai Hospital, who showed in biological psychiatry that the stress and trauma experienced by Holocaust victims have an intergenerational effect. The trauma experienced by the study group of 32 Jewish women and men in concentration camps was so extreme that it also replicated in their children.
The researchers were able to prove that the methylation of one of the genes (FK506, being associated with an increased risk of developing the stress of post-traumatic depression or attack anxiety) in 22 descendants of Holocaust witnesses (participants in the expert study) could only be the result of the apocalyptic experience of war that their parents endured.
When the results of the study were compared with a control group that qualified Jewish families living during World War II outside of Europe, it turned out that they had a completely different pattern of cytosine methylation. The descendants of those who experienced extreme war experiences had a clear association with the pattern observed by their parents. According to researchers, the power of traumatic experiences was so great that the trauma was reflected even in subsequent generations.
What diseases can be inherited from mother and father?
Are you suffering from insomnia? Probably, problems with falling asleep are transferred by the mother. According to the researchers in the pages of Sleep medicine, our mothers pass on by genes how we usually fall asleep, favorite positions during sleep and its quality (this was not seen in the case of fathers).
The genes that our mother passes on may also depend to a certain extent on the rate at which our body ages, although we do not care about a healthy lifestyle, do not count on longevity, smoke cigarettes, consume excessive amounts of alcohol, etc.
Women usually go through menopause at the same age as their mothers and grandmothers, and sons have inherited their male ancestors, among other risks of developing prostate or colorectal cancer. They are also at risk of color blindness, which, as a hereditary defect, most often affects men (so it is usually harder to notice as many colors as women).
Fathers can also pass on genetic diseases to their male offspring, such as:
- hemophilia
- Hunter syndrome (mucopolysaccharidosis type II)
- mental disability (Martin syndrome, often confused with autism)
- Duchenne muscular dystrophy (leading to muscle atrophy)
- associated with infertility, penile hypoplasia, and clinical Klinfelter syndrome (XXY)
- the so-called ichthyosis manifests itself on the skin, associated with a defective X chromosome
Scientists confirm that genes inherited from the father tend to be more active than those in the mother's genetic line. Professor Fernando Pardo-Manuel de Ville, of the University of North Carolina School of Medicine, has proven that our DNA fragments from our dads have more of an effect on us (as they do in all mammals).
In turn, from our mothers we can inherit this tendency among others for such diseases:
- osteoporosis
- hypertension
- hypothyroidism
- varicose veins
- Alzheimer's disease
- uterine fibroids or endometriosis (in women)
The development of each person begins with a cell. It contains information (about certain character traits, appearance, diseases) received by the baby from the parents. Try to determine .
Of course, nothing can be said for sure, but trying to imagine the general signs of appearance and even the character of the baby is quite realistic. Just do not think that he will be a copy of one of the parents. The child will be an independent person. Moreover, how talented and extraordinary he will be depends not only on genes. Parents should remember that the influence of genes on heredity is, of course, great. But what kind of personality a child develops can largely be influenced by them themselves. For example, to educate a strong character, heredity alone is not enough, you also need the right upbringing.
Is it possible to determine the sex of the unborn child? All information about a person is contained in DNA, which are part of chromosomes (located in the cell nucleus). Each species of plants and animals contains a certain number of chromosomes. A person has 46 of them. A child receives 23 chromosomes from mom and 23 from dad. The sex of the child depends on the men. The egg contains only one sex X chromosome. A sperm cell can carry both the X and Y chromosomes. If the egg is fertilized by a sperm with a Y chromosome, a boy (XY) will be born. If the X chromosome, then, respectively, a girl (XX). It is still impossible to predict who will be born.
What will the child look like? Of course, it is impossible to predict the appearance of the crumbs. But you can say with a certain degree of certainty what the main features will be. Dominant (strong) and recessive (weak) genes will help us with this.
strong genes...........................................................................Weak genes
dark, coarse, curly hair..................light, straight, soft hair
dark eyes................................................ ...............................light eyes
big hooked nose ................................. narrow nose and small nostrils
wide chin .............................................................. ...................... narrow chin
full lips................................................ ..............................thin lips
dark skin .................................................................. ............................bright skin
When a strong and a weak gene meet, the strong one usually wins. For example, mom is brown-eyed brunette, and dad is blond with blue eyes, with a high degree of probability we can say that the baby will be born with dark hair and brown eyes.
True, brown-eyed parents may have a newborn with blue eyes. Thus, the genes received from the grandmother or the grandfather could affect. The opposite situation is also possible.
hereditary diseases. A baby can inherit from his parents not only appearance and character traits, but also diseases (cardiovascular, oncological, diabetes, Alzheimer's and Parkinson's).
The disease may not manifest itself if elementary safety measures are taken. Tell the gynecologist in detail about serious health problems not only for you and your husband, but also for close relatives. This will help protect the baby in the future. Sometimes completely healthy parents give birth to a baby with a hereditary disease. It was laid down in the genes and manifested itself only in the baby. This usually happens when both parents have the same disease in their genes. Therefore, if a child is planned, according to experts, it is better to undergo a genetic examination. This is especially true of a family in which children with hereditary ailments were already born.
Fact
Babies are more like dads. Nature "conceived" so that the man immediately saw himself in the child and the instinct of paternity was formed faster.
For mom or dad?
The child, as a rule, inherits the color of the eyes of the parent, whose eyes are darker. For example, a brown-eyed mother and a blue-eyed father, even if the baby is a copy of the father, the eyes will most likely be brown.
If one of the parents has curly hair, then the firstborn is likely to have curls too.
Is the first child a boy? Then he will surely look like a mother with the help of the gene and chromosomes transmitted to the child. The girl is on dad. In such cases, they say: "He will be happy."
The mind and ingenuity of the baby inherits from the mother. The latter, by the way, is confirmed by science. The fact is that the genes “responsible” for IQ are located on the X chromosomes, of which women have two (XX), and men have one (XY).
A girl born from a brilliant father is much more likely to be known as a clever woman, but nature will most likely “rest” on the son of a brilliant personality.
The baby will be light-headed "in mother" only if the blondes were also among the father's relatives.
Bad habits are encoded at the genetic level. Alcohol dependence is determined by the gene responsible for the synthesis of an enzyme that breaks down alcohol. If the gene is mutated, then the child of parents who like to drink, there is a tendency to alcoholism.
character by inheritance
The fact that character is inherited with the help of a gene and chromosomes transmitted to a child has not yet been scientifically confirmed. Although the “aggressiveness gene” discovered by scientists a few years ago has already given ground for this kind of talk. True, practical experiments disproved them. And yet it was not in vain that Russian rumor advised, when choosing a wife, to look at the future mother-in-law. How many times have you already said, looking at your daughter: “Well, stubborn - all like a grandfather!” or noticed in the son: "Oh, the character is paternal." Yes, all this can be attributed to the so-called costs of education. The fact that the child unconsciously copies the behavior of the parents, noticing how they behave in a certain situation. Then he repeats the act in similar conditions. Meanwhile, scientists working on deciphering the human genetic code have already established that the tendency to polite or rude behavior is 34% genetically inherent in us. The rest is determined by upbringing and environment. And even the choice of a profession, we owe 40% to a certain combination of chromosomes. At the very least, leadership qualities in most cases are inherited. Perhaps that is why in Rus' there was a dynastic principle of transferring royal power - from father to son.
"Neither mother nor father..."
Indeed, it happens that a son or daughter is not at all like their parents. They can easily repeat the genotype of some distant relative. Or very far. And he left this world a long time ago.
The dissimilarity to anyone often worries the father very much. Tell your beloved husband that your child is like your great-great-grandmother or - and he will calm down for a while.
And also look at your husband’s childhood photographs, and you will see: the appearance of a growing child is constantly changing, and in a year or two your crumbs may show a lot of your features.
Geneticist and Ph.D. Dean Hamer first announced the existence of a "homosexual gene" in 1993, and in 2004 wrote a book about the discovery of a "faith in God gene."
British scientists analyzed the nature of 609 pairs of twins and it turned out that if the ability to run one's own business, sociability and introversion were characteristic of one of the brothers, then they were necessarily present in the character of the other. Even such a habit as the desire to sit in front of the TV for a long time is 45% inherited. And scientists have long and seriously argued about the “gene of genius” and the possibility of its isolation, and even its introduction, into the genotype of a particular person. At the same time, the subject of the dispute is the moral component of the issue, and not scientific hypotheses at all. As Sherlock Holmes once said, looking at the portraits of the Baskerville dynasty: “So don’t believe in the transmigration of souls after that!”
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