The answer is Yesenia Pavlotski, linguist-morphologist, expert at the Institute of Philology, Mass Communication and Psychology, Novosibirsk State Pedagogical University.
The question concerns how to name and define the biological characteristics of several organisms born from humans.
Start with the fact that twins children of one mother are called, developed during one pregnancy and born as a result of one childbirth after a short time one after another. Such children are called twins, regardless of whether they are homozygous (identical) or heterozygous (two genetically and externally different children).
Twins- two twins. The nomination in this case depends on the number of fetuses in pregnancy: twins, triplets. Less commonly, quadruplets. The words fours, fives, gears and so on, seem to be erroneous, since language reflects reality, and in reality, a multiple pregnancy of a person is most often limited to two fetuses. Four, five, six or more twins are very rare, so the language does not seem to need a word for this object, that is, the use of such a word does not differ in the frequency of reproduction.
Respectively, twins can not always be called twins, since there can be more than two of them, but twins Is always Twins: Ordinary sisters, brothers or siblings cannot be called twins.
Despite such a dictionary distinction, there is an established use of these words in one more sense.
When talking about two children born at the same time, and trying to figure out what type of twins we are talking about, people choose the words to separate homo- and heterozygous twins twins and Twins as opposed concepts.
Homozygous twins are identical, they have one common genotype for two. Heterozygous twins are two different babies with different genotypes developing in different eggs at the same time. Precisely in order to understand what type of speech people are talking about, people use the words twins and Twins if there are two children.
You can often hear “ they are not twins, but twins". That is, twins are called children who can be confused (common genotype = one appearance for two), and twins are those who were born together, but are at the same time completely different people - the same children could be born with a difference of 10 years.
The latter case is not a vocabulary fixation, but an established speech practice and observation of the language, so this explanation should not be taken as a rule.
So, twins can not always be called twins, but twins Is always Twins.
From Wikipedia, the free encyclopedia
In the case of two-egg (heterozygous) twins, each of the fetal eggs (blastocysts), after insertion into the decidual (falling off) membrane of the uterine wall, forms its own aqueous and villous membrane, from which a separate (own) placenta with an independent network of fetal blood vessels develops further for each fetus. ... In this case, often both placentas remain separate. Even in cases where the edges of both placentas are closely adjacent to each other (as if merging into a single whole), nevertheless, the villous and watery membranes of each of the gestational eggs remain separate, while the capsular membrane is common to them.
Multiple twins (as well as identical twins) are not only twins, but also triplets, quadruples, and so on up to 9 children. In addition, there have been cases when, for example, two identical (homozygous) twins and one not identical (heterozygous in relation to the other two) were born in triplets.
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Literature
- G. M. Savelyeva, V. I. Kulakov. Obstetrics. - M.: Medicine, 2000. - S. 816. - ISBN 5-225-04549-9
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Excerpt from Multiple Twins
The next day the troops gathered in the evening at the designated places and marched out at night. It was an autumn night with purple-black clouds, but no rain. The ground was wet, but there was no mud, and the troops marched silently, only the occasional strumming of artillery was faintly audible. Forbidden to talk loudly, smoke pipes, strike fire; the horses were kept from neighing. The mystery of the enterprise increased its appeal. People walked merrily. Some of the columns stopped, put their guns in the box and lay down on the cold ground, believing that they had come where they needed to; some (most) of the columns walked the whole night and, obviously, went in the wrong place.
Count Orlov Denisov with the Cossacks (the most insignificant detachment of all the others) alone got into his place in his own time. This detachment stopped at the extreme edge of the forest, on the path from the village of Stromilova to Dmitrovskoe.
Before dawn, the dozing Count Orlov was awakened. They brought in a defector from the French camp. It was a Polish non-commissioned officer in the Poniatowski corps. This non-commissioned officer explained in Polish that he had run over because he had been offended in his service, that he should have been an officer long ago, that he was the bravest of all and therefore had abandoned them and wanted to punish them. He said that Murat was spending the night a mile away from them, and that if he was given a hundred men in an escort, he would take him alive. Count Orlov Denisov consulted with his comrades. The offer was too flattering to refuse. Everyone volunteered to go, everyone advised to try. After many disputes and considerations, Major General Grekov with two Cossack regiments decided to go with a non-commissioned officer.
“Well, remember,” said Count Orlov Denisov to the non-commissioned officer, letting him go, “if you lied, I’ll tell you to be hanged like a dog, but the truth is, a hundred ducats.”
The non-commissioned officer with a resolute air did not answer these words, sat on horseback and rode off with the quickly assembled Grekov. They disappeared into the woods. Count Orlov, shrinking from the freshness of the dawning morning, agitated by the fact that he was undertaking his own responsibility, having escorted Grekov, went out of the forest and began to look around the enemy camp, which was now deceptively seen in the light of the beginning of the morning and the dying fires. To the right of Count Orlov Denisov, along the open slope, our columns were to appear. Count Orlov was looking there; but in spite of the fact that they would have been visible from afar, these columns were not visible. In the French camp, as it seemed to Count Orlov Denisov, and especially in the words of his very keen adjutant, they began to stir.
“Oh, really, it's late,” said Count Orlov, looking at the camp. He suddenly, as often happens, after the person whom we believe is no longer in front of his eyes, it suddenly became quite clear and obvious to him that the non-commissioned officer was this deceiver, that he had lied and would only ruin the whole matter of the attack by the absence of these two regiments, whom he will lead, God knows where. Is it possible to snatch the commander-in-chief out of such a mass of troops?
“Indeed, he’s lying, that rogue,” said the count.
“You can turn it back,” said one of the retinue, who felt, just like Count Orlov Denisov, mistrust of the enterprise when he looked at the camp.
- A? Right? .. what do you think, or leave? Or not?
- Will you order to turn it back?
- Turn back, turn back! - Count Orlov suddenly said resolutely, looking at his watch, - it will be too late, quite light.
And the adjutant galloped through the forest after Grekov. When Grekov returned, Count Orlov Denisov, agitated by this canceled attempt, and the vain expectation of infantry columns, which all did not show, and the proximity of the enemy (all the people of his detachment experienced the same), decided to attack.
In a whisper he commanded: "Sit down!" Distributed, crossed themselves ...
- With God blessing!
"Uraaaaa!" - rustled through the forest, and, one hundred after another, as if spilling out of a sack, the Cossacks flew merrily with their darts at the ready, across the stream to the camp.
Throughout the history of evolution, scientists have identified in nature two types of twins: monozygous (identical) and dizygotic twins (fraternal).
Monozygotic twins are a consequence of multiple pregnancies, which arose from the fertilization of one egg and the development of two or more fetuses in it. The prevalence of monozygotic twins is quite low, but dizygotic (fraternal) twins are more common.
The emergence of monozygous twins, scientists associate with the fertilization of an egg, which had two or more nuclei. Each nucleus is connected to the nuclear substance of the sperm, because of which the rudiments of embryos begin to form. During the development of the ovum, at the very beginning, the chorion and amnion are laid, and then the formation of the embryo itself. Therefore, the features of placentation during the formation of monozygotic twins depend on the stage of development of the ovum, at which its division occurs.
Features of the phenomenon
Since ancient times, when the subtleties of genetics and anatomy were still alien to people, the birth of two completely identical people was equated with something supernatural. They could be attributed to both divine and devilish properties.
For example, the American Indians had a belief that one of these twins is a product of evil, and the other is good. Therefore, the "evil" twin always soon awaited expulsion from the tribe.
Our Slavic ancestors believed that twins have one soul. Therefore, one twin was never allowed to be present at the wedding or funeral ceremony of the other. Also in Slavic and Indian culture, people believed that the birth of twins is a kind of natural whim. And therefore, the people believed that such children could "negotiate" with nature itself.
But if you look at this phenomenon today, from the point of view of science, then in fact, monozygous twins have the same genotype, as a result of which they have an amazing similarity with each other and they are always of the same sex. It is for these reasons that they are called identical. It should be noted that the similarities of such children are not only portrait. Of course, these are two completely different personalities, but quite often the features of behavior, habits, character and even the choice of profession in the future may coincide.
Scientists have always had a special interest in monozygotic twins, which is why they are so fond of conducting a variety of studies with the participation of such twins.
Not so long ago, scientists found out that there are some differences in the genomes of identical twins. And in 2008, a group of American, Swedish and scientists in the course of research found that monozygotic twins may also have genetic mismatches. After studying the genomes of nineteen pairs of such twins, scientists found some mismatches in the copies of DNA segments of somatic cells. Despite the fact that identical twins are almost identical, some differences were found in the majority.
Another feature is that many brothers and sisters who were born on the same day grow up in the same environment. Twins most often receive the same gifts, toys, and also, in most cases, start going to the same school, and so on. Of course, they might have different interests. For example, there are common preferences in literature, but mothers and fathers usually read the same books to them. And, naturally, no one will deliberately separate children and try to raise them in different conditions, since this is inhuman. The exceptions are those cases when fate itself divides people against their will.
An enormous study was carried out in the early 80s of the twentieth century by an American psychologist, whose name is known as - Thomas Bouchard. In total, the objects of his research were thirty pairs of twins, who, by the will of circumstances, were separated from early childhood. One such pair was the monozygous twins, brothers Oscar and Jack. Some time later, after the birth of the boys, the marriage broke up and as a result, the mother took Oscar to her homeland in Germany. A few years later, Oskar joined the Hitler Youth, after which he became a believing Catholic. And Jack grew up with his father in Palestine, and later in the Caribbean, where he was brought up in all the traditions of Judaism.
As a result, the meeting of the brothers took place only at the age of forty. The most amazing thing about this story is that, despite the differences in upbringing, living environment and language, there were many similarities in their behavior and characters. Both had the same temperament, with very similar clothing and food preferences. But the most surprising thing was that they wore almost the same glasses and even the same cropped mustache. Both brothers were rather scattered, and their style of communication in their families was the same.
Sisters Loise and Louis are another example. The girls were born in 1920 and after birth they were separated after some time. They were brought up in different families and their levels of education, places of residence were completely different. Louise grew up in a small town and attended the most ordinary school. Lois lived in a big city and studied in a more prestigious institution. Although the economic condition of both families was approximately at the same level. Probably, this is precisely what caused the girls to enter the same institute at the age of eighteen. And as studies have shown, in terms of physical and psychological traits, the girls turned out to be extremely and incredibly similar. There was a far greater resemblance between them than many sisters and brothers who grew up together all their lives.
Well, another amusing example was in the United States, when two monozygotic twins separated in childhood chose the same field of activity, which was distinguished by its specificity. Ultimately, both brothers soon became safe crackers.
Despite this, scientists are extremely wary of the hereditary role. As many studies have shown, monozygotic twins have a fairly similar "criminal history" in 50-70% of cases. In dizygotic twins, this phenomenon is much less common, only about 20% of cases.
Of course, there are many stories of some kind of telepathic connection between identical twins, which may not be believed. But the fact that these children can understand each other much better than ordinary brothers and sisters has long been confirmed. Very often, as they grow older, monozygotic twins find it quite difficult to form some kind of separate independent personality. After all, from childhood they are even dressed in the same clothes, read the same books, give the same gifts. This often leads to the fact that twins are practically inseparable throughout their lives.
Also, according to some characteristics, monozygotic twins should have an extremely similar consciousness. For example, they may have the same addictions to dishes from the same cuisine, or they may part ways with their beloved. Perhaps this explains the fact that in the fates of such brothers and sisters there are such strange coincidences, even in the smallest things.
Identical twins in case of IVF
During the IVF procedure, conception, as such, occurs in a test tube, and after about three days, the resulting embryos are implanted into the woman's uterus, where they begin their further development. And in order for the chance of pregnancy to be higher, doctors always place more than two embryos (from two to three) into the uterus, in the hope that at least one will begin to take root.
In some cases, several embryos can take root at once, and in the process of implantation into the uterus, one of the zygotes is divided into two more and then identical twins begin to develop from the cell. As soon as the onset of pregnancy by the IVF method is confirmed, the woman is informed about the number of fetuses that have taken root, and if there are more than two of them, then, so that the chances of successful bearing without complications are higher, the extra embryos are removed.
How monozygous twins will develop depends largely on the presence of one placenta and a bladder.
If two fetuses are located in separate bubbles and at the same time with one placenta, then there may be a risk of "dehydration" of one of them. In other words, the "stronger" identical twin gets much more of the nutrients it needs. In this situation, when the moment of birth comes, a "weak" baby can be born 400-600 g less than his identical twin. In severe cases, such a baby may lag slightly behind in development from his brother or sister.
Sometimes it happens that on the fifth week of the ultrasound, doctors can see two embryos, which they have implanted in the uterus, and on the next ultrasound of the seventh or eighth week, three embryos can be clearly seen in the uterus. This can be observed in cases where one of the zygotes has split, and as a result, monozygotic twins have begun to form.
As for the sex of such twins, then, as mentioned earlier, they will definitely have one, since the birth of children occurs as a result of the division of one fertilized egg and the sex will be determined after the process of fusion of the cells of the mother and father.
Twin children with the same heredity, as a result of separate education, sometimes become more similar to each other than if they are brought up together. This somewhat unexpected fact is explained by the fact that children of the same age, who are constantly next to each other, almost never manage to do the same thing, and between such children, completely equal relations rarely develop.
Despite the great similarity in a number of psychological and behavioral characteristics that is found among homozygous twins, the statement that their psychological commonality is determined only genetically is hardly fully justified. The studies carried out and the results obtained in them make it possible to consider the influence of the environment on the mental and behavioral development of an individual to be stronger than the influence of his heredity.
A comparative study of the role of heredity and the environment and their influence on psychology and human behavior is usually carried out in one of the following ways:
1. Systematic variation in the conditions of education and upbringing, versatile study of children who grew up in different social cultures, regions and families.
2. Comparative study of the psychology and behavior of homozygous and heterozygous twin pairs.
Much attention was paid to the problem of studying the individual psychological differences of children in our country in the studies conducted by B.M. Teplov and his students. The first of these studies were aimed mainly at establishing whether there are congenital types of higher nervous activity and, if so, how they are determined. These studies experimentally tested the hypothesis that one of the inherited, genetically determined factors is the type of the human nervous system, which in turn depends on the combination of its basic properties.
The properties of the nervous system are understood to be such stable qualities that are innate. These properties include:
1. The strength of the nervous system in relation to arousal, i.e. its ability to withstand for a long time, without detecting prohibitive braking, intense and often repetitive loads.
2. The strength of the nervous system in relation to inhibition, i.e. the ability to withstand long-term and frequently repeated braking influences.
3. Balance of the nervous system in relation to excitation and inhibition, which manifests itself in the same reactivity of the nervous system in response to excitatory and inhibitory influences.
4. Lability of the nervous system, assessed by the rate of onset and termination of the nervous process of excitation or inhibition.
At present, a 12-dimensional classification of the properties of the human nervous system (VD Nebylytsyn) has developed in differential psychology. It includes 8 primary properties (strength, mobility, dynamism and lability in relation to excitation and inhibition) and four secondary properties (balance in these basic properties). It is shown that these properties can relate to the entire nervous system (its general properties) and to individual analyzers (partial properties).
VM Rusalov further developed the ideas of the Teplov-Nebylitsyn school and proposed a three-level classification of the properties of the nervous system 1. 1 (Rusakov V.M.Differential Psychology: Main Achievements and Prospects for Studying Human Individuality // Psychological Journal. - 1988. -T. 1. - No. 2.)
It includes:
1. General, or systemic, properties that cover the entire human brain and characterize the dynamics of its work as a whole.
2. Complex properties, manifested in the peculiarities of the work of individual "blocks" of the brain (hemispheres, frontal lobes, analyzers, anatomically and functionally separated subcortical structures, etc.).
3. The simplest, or elementary, properties correlated with the work of individual neurons.
On the basis of the studies carried out concerning the connection between the properties of the human nervous system and the solution of problems (thinking), V.M. Rusalov came to the conclusion that only the formal dynamic characteristics of a person's mental activity are determined mainly (but also not exclusively!) By biological factors.
Thus, the properties of the nervous system do not predetermine the mental qualities and forms of human behavior, and therefore they cannot be considered as inclinations for the development of abilities. At the same time, as BM Teplov wrote, they "form the ground on which some forms of behavior are more easily formed, others are more difficult" 2. 2 (Teplov B.M. The current state of the issue of the types of higher nervous activity and their definition // Psychology of individual differences: Texts. - M., 1982. - S. 25.)
Since the basic properties of the human nervous system are quite stable, the practical task of studying them in connection with the problem of individual differences is not to search for their change, but to find the best path and method for teaching children with this type of nervous system for each type of nervous system.
Developing in this regard the ideas of B.M. Teplov, V.D. Nebylitsyn expressed the idea that a special combination of the basic properties of the nervous system, i.e. each of its types has its own advantages and disadvantages. Under conditions, for example, of monotonous work, people with a weak type of nervous system show the best results, and when switching to work associated with large and unexpected loads, on the contrary, people with a strong nervous system.
A person's complex of individual-typological properties of his nervous system primarily determines the temperament, on which the individual style of activity further depends.
Let us now turn to a direct analysis of some facts testifying for and against the genotypic conditioning of individual differences in the cognitive processes and intellectual characteristics of children, i.e. in their inclinations.
In the results of studies that were aimed at identifying the hereditary conditioning of intelligence, there is a lot of controversy. In some cases, the connection between intellectual abilities and heredity is found, in others it is not. However, "the typical result obtained in twins on intelligence tests is that monozygous ones are intrapaired more similar than dizygotic ones." "(Ravich-Scherbo IV Study of the nature of individual differences by the method of twins // Psychology of individual differences: Texts. - M., 1982. -S. PO.)
At the same time, the influence of the environment on the psychology of monozygotic twins is also obvious and increases with age, while the influence of genotypic factors, on the contrary, decreases.
There are not so many psychological properties that could be considered hereditary with certainty. Among the characteristics that have a clear genotypic prerequisite is, for example, the pace of a person's work, on which temperament in turn depends. A particularly great influence of the genotype is found in the study of some physiological indicators, for example, an electroencephalogram.
However - and this is a very important fact - none of the known properties of the nervous system is exclusively dependent on the genotype, since it is itself, to a certain extent, influenced by the environment. IVRavich-Shcherbo writes: “The higher the role of specifically human, speech voluntary self-regulation in activity, the less role genotype factors play, and vice versa, the lower it is, the more distinctly the individual characteristics of this activity are determined by heredity” 1. "(Ibid.).
The data presented allow us to make a quite definite conclusion about the absence of a pronounced biological and about the presence of a distinct social conditionality of the inclinations, in this case, the main properties of the human nervous system, but they do not remove another important issue and suggest its special discussion. This is the question of the genotypic conditioning of inter-sex psychological and behavioral differences. There is an opinion that they are largely determined by the genotype, gender, biological identity of a person. Is this really so and what can modern science say about this?
Analysis of the data obtained in many experimental comparative psychological studies shows that general judgments such as "Girls are better at speech than boys", "Boys are more inclined to mathematics than girls", "Girls have better memory than boys, but boys are superior to them in abstract thinking "," Girls are more passive and more sensitive to approval of their behavior from the outside than boys "," Boys are more aggressive and more independent in their behavior than girls "are not entirely true. There are no significant differences in the level of general intellectual development between male and female children.
At the same time, there are still small age differences in the manifestation of private abilities between them. Evidence from some studies shows that between the ages of 10 and 11, girls do have slightly more vocabulary than boys and are better at reading written texts and fluent in language. At the same age, boys are superior to them in other respects, for example, in the ability to spatial orientation, in reading drawings, geographical maps, in geometric abilities. After the age of 13, boys develop mathematical abilities somewhat faster than girls, but not enough to lead to significant gender differences later. At the same time, it should be borne in mind that small average sex differences in these abilities are usually much less than those interindividual differences that exist within the same sex.
As for personality traits, there are no noticeable differences in children of different sexes at preschool age. Intersexual differences in the early stages of ontogenesis manifest themselves noticeably only in connection with one feature - external aggressive behavior. In boys, it is more pronounced than in girls, starting from two to three years of age. However, this is more likely a result of gender differences in parenting practices than a consequence of biological factors.
Thus, the genotypic dependence of the behavior and psychology of people is not confirmed in relation to sex differences. They, as we found out earlier, directly depend on education and upbringing, which in the conditions of most cultures existing on Earth from the very birth of a child and throughout his entire childhood are completely different, and so much so that we should rather be surprised by the fact that there is in the psychology and behavior of men and women, and not their differences.
With age, however, due to the influence of life experience and professional activity, some sex differences may increase. The data of the conducted studies show that, on average, adult men engaged in physical types of labor can surpass women in coordination of movements, orientation in space, understanding of mechanical technical connections, and mathematical reasoning. Women, in turn, can outperform men in terms of manual dexterity, speed of perception, counting, memory, fluency, and other abilities, including mastery of speech.
The following fact is also remarkable. Everyday experience suggests that the occupation of women by traditionally male, and by female, types of professional labor supposedly form in them the psychological characteristics characteristic of people of the opposite sex, i.e. lead to the masculinization of women and the feminization of men. This assumption is only partially supported by the facts. Indeed, the types of activities traditionally characteristic of people of the opposite sex contribute to the formation and development of traits associated with these types of activities, but these are actually professionally determined traits, and not those that could be considered sex-related. As it turned out, such activities do not particularly affect the change in the actual sex-role forms of behavior.
Studies carried out in special, strictly controlled experimental conditions provide a basis for the conclusion that socio-cultural factors associated with the development of abilities have a much stronger influence on them than biological ones. The average differences between groups of people raised in different cultures are often much larger than those that exist between people of different genders.
The birth of a child is an unusual, fascinating moment. The whole life of a young mother begins to revolve around a small miracle that has come into the world. And if a woman is presented with two (or more) babies, then there will be more happiness.
The birth of twins brings with it excitement, the upcoming chores of care, sleepless nights, but the moment of the birth of children is filled with happiness.
Types of twins
If a woman is fixed, then she will have twins. Children can be both exactly the same, and generally not very similar, and even different sexes. It all depends on the egg cell. Depending on this, the twins are divided into:
- identical (monozygous);
- raznoyaytsevye (dizygotic).
Identical twins
The birth of two absolutely identical children remains a mystery to humanity. Why, at the initial stage, the egg cell begins to divide and create the same embryos remains unknown.
Monozygous twins are the result of the fertilization of one egg with one sperm. The resulting diploid cell begins to divide, resulting in the formation of independent embryos. Most often there are two, but there may be more. The similarity of future babies from such a pregnancy is determined by the time of separation of the embryos. If it happened in the first 5 days, then the embryos each have their own placenta and amniotic fluid. In this case, there will be minor differences in the appearance of future babies. If the separation occurred after the fifth day, then the embryos have one common placenta and their similarity with each other becomes absolute.
Fun fact: Monozygotic twins have identical fingerprints in most cases.
The reasons for the division of the zygote into two or more identical embryos have not yet been studied. The probability of having identical babies is 3 in 1000 and does not depend on heredity.
Gemini fraternal
Such twins are conceived as a result of the fertilization of two eggs with different sperm. During intrauterine development, each embryo has its own placenta and develops independently of the other. Dizygotic twins can be either same-sex or heterosexual. They will have an outward resemblance, like those of brothers and sisters born from an ordinary singleton pregnancy.
Gemini fraternal conceptions can be several hours apart, and possibly even several days apart.
Features of the development of dizygotic twins
The following facts are known about the birth of fraternal twins:
- their genes coincide by about 40-50%;
- each embryo has its own placenta and its own amniotic fluid;
- born babies can be either same-sex or heterosexual;
- children can have different blood types;
- the likelihood of their occurrence increases in women over 35;
- as a result of the IVF procedure, twins most often appear, since the woman gets a few
Is it realistic to schedule the birth of twins?
The birth of a child is an unusual, fascinating feeling that arises in a young mother who gave birth to a child. And birth is even more conducive to the feeling of happiness. However, it is impossible to schedule their appearance.
When the egg is fertilized, information is immediately laid down both about the future baby and about what kind of pregnancy it will be - singleton or multiple, so it is impossible to influence this process in a natural way. You can only find out the factors, when observed, the likelihood of having twins increases.
These factors include:
- pregnancy at the age of 35-39;
- the presence of twins in a generation (the appearance of identical ones is not associated with hereditary factors. To date, it has not been studied why and under what conditions the egg cell begins to divide);
- short menstrual cycle (20-21 days) - with such a cycle, the likelihood of several eggs maturing increases;
- infertility treatment. In the treatment of infertility, hormonal drugs are used that also stimulate ovulation, the result can be multiple pregnancies;
- artificial insemination - in vitro, often leads to the birth of twins or even more babies.
Differences between twins and twins
We can summarize how identical twins differ from fraternal twins. Consider the characteristics that babies born with multiple pregnancies will have.
Identical twins:
- Children have an identical resemblance, however in some moments it can be mirrored. For example, a mirror image of existing moles.
- In addition to the external similarity, the physique, the structure of the hair, the arrangement of the teeth, the timbre of the voice are the same, and even the thoughts are quite similar.
- They have the same blood group and most often have similar fingerprints.
- Always same-sex, they are also called natural clones.
- It is impossible to schedule the birth of monozygotic twins.
Gemini is fraternal:
- There are both same-sex and heterosexual.
- May have different blood types.
- The outward resemblance is superficial.
As you can see, there are no similarities between identical and fraternal twins, only one name - "twins". At the same time, it is customary among the people to call identical babies twins, and non-identical babies - twins, triplets, etc. Differences between them begin to appear from the moment of conception.
Conclusion
The appearance of two or more babies as a result of one pregnancy brings with it an increased attention of people around them to children. At the same time, fraternal twins look like an ordinary brother and sister (2 sisters or 2 brothers), so they do not attract close attention.
Identical twins are always of interest in society. Most likely, this is due to the rarity of such a phenomenon. Therefore, seeing two absolutely identical people, a passer-by will definitely stop his eyes on them.
In this case, you need to know that multiple pregnancies are observed under special control, since the body is experiencing a greater load than during a normal pregnancy. The expectant mother should be attentive to her health. Therefore, in order to give birth to healthy twins, it is necessary to listen to the doctor's recommendations, then the moment of meeting with babies will be filled only with positive.
