How genetics affect your child's appearance and personality.
How does genetics work?
While Waiting for the baby Maybe you've tried to picture what he might look like. Will he be tall like his father? Will he have curly hair like you? Or will he inherit his grandfather's sense of humor?
Experts estimate that there are between 60 and 000 genes (made up of DNA) in a human's 100000 chromosomes. A child receives 46 chromosomes from their mother and 23 from their father. With all the possible genetic combinations, a single pair of parents could produce 23 trillion different offspring. This probably gives you an idea of how impossible it is to predict what your child will look like. Genetics is complex, but with a short course, you can gain some information to guide your imagination.
Remember learning about genes and fruit flies in high school biology? Back then, you were told that a dominant gene always blows up a recessive gene. Well, scientists have always known that humans are more complex than fruit flies. But in recent years, they've learned just how complex.
As it turns out, most human traits are polygenic—the result of many genes working together. To complicate matters further, some traits—such as height, weight, and, especially, personality—also have a significant influence on which genes are expressed and which remain silent.
Good morning
If only one pair of genes were involved in determining eye color, there would be three shades of eye color—brown, blue, and possibly green. But human eyes come in a whole range of different shades of these colors. That's because eye color is a polygenic trait.
Eye color is determined by the amount of melanin, or brown pigment, in the iris. Dark eyes have large amounts, blue eyes have very little, and other colors—green, hazel—have varying amounts. Because different genes are likely responsible for how much brown pigment you inherit and where it appears in the eye (brown or blue pigment can fall in the center or outer edges of the eye), there's a great potential for a variety of hues. It's even possible for blue-eyed parents to have brown-eyed offspring.
Facial and body features
It is believed that some facial characteristics such as: boils Facial symmetry (a thin eyebrow on one side of your face, for example), hand shape, finger shape, toenail shape, and unusual features like double hair often appear across generations.
Fingerprint patterns have been shown to run in families. Crooked teeth can also be inherited, as jaw shape and tooth alignment are genetically determined. A gene specific to "gap teeth" has even been discovered and is believed to be dominant.
To get an idea of the facial features your child might inherit, examine photos of relatives across generations. If most family members have a prominent chin or a round face, these are strong traits that are likely to be passed on.
Height and weight
To get a rough estimate of height, take the average height of the mother and father. Then add 5 inches for a boy or subtract 2 inches for a girl. So if you are 5 feet 10 inches and your husband is 5 feet 6 inches, the average between you is 5 feet 8 inches. Therefore, your son will likely grow to be 5 feet 4 inches, your daughter, XNUMX feet XNUMX inches. Of course, genetics being what it is—it's unpredictable—this metric isn't set in stone. Your child may turn out to be taller than the parent.
Nutrition and health are other powerful factors in determining your child's final height. If your child's genes are programmed for 5 feet 5 inches, they may not reach that height if their diet is inadequate or if something else interferes with their growth. On the other hand, they may grow taller than expected, as studies have shown that improved diets have contributed to greater height over the centuries.
It's impossible to predict how overweight or underweight your child will be. Genetics will only influence a child's weight—it doesn't guarantee it. When both children are obese, the child is more likely to be overweight as well. A child may become obese because of their genes or eating habits In the family or a combination of both factors.
hair colour
Generally, dark hair is dominant over light. But just as with eye color, your baby's hair can be a beautiful range of shades between your own and your partner's. It depends on the colors, or pigments, in your hair and how they blend. Parents with similar hair colors may have a child with a slightly different color, but within their range.
But surprising colors can certainly appear from parents with different hair colors. This usually occurs when a recessive color gene from one parent mixes with the other. So, a black-haired parent who carries a recessive gene for blond hair may have a blond child if that gene is expressed and mixes with a blond gene from the other parent.
Red hair, once considered recessive, is now thought to be dominant over blonde. You can even be a redhead. Your hair may be dyed a greenish-red color using a stronger brown or black dye.
Personal
Experts say there's no doubt that many personality tendencies—for example, how you react to noise—are genetically inherited at birth. But experts also agree that the environment has a significant influence on behavior. For example, a child may inherit a tendency to jump into risky activities (a "novelty-seeking" gene has been identified). However, your influence on their environment may cause them to express their adventurous spirit to a lesser extent, in a different way, or not at all.
In the same way, children who inherit a creative bent or a perfect pitch (as it has been shown to be genetic) will thrive in an encouraging environment. But if they aren't exposed to art materials or musical instruments, talents may lie dormant. Fortunately, it works the other way around as well—a child born without this genetic inheritance can, through hard work and determination, learn to paint or develop a good floor. There is hardly any trait that is entirely genetic or entirely environmental.
Pregnancy with twins
Pregnancy with identical twins, which come from a single fertilized egg that splits into embryos, occurs by chance. There's no known genetic link. But pregnancy with fraternal twins, babies born from two separate eggs and one sperm, appears to be genetically influenced. That's because a woman's tendency to ovulate more than one egg at a time is inherited. So if there's a history of fraternal twins in your family, you have a higher chance of having a set, too.
The big question is whether double or multiple ovulation is a recessive or dominant gene. This is difficult to determine, since more twins are conceived than are born. One twin could die in utero, or a woman could miscarry both twins so early in the pregnancy that she may not even know she was expecting. Since experts don't know how many fraternal twins there are, they can't be certain whether the gene is dominant.
With all the possible combinations of genes that influence your baby's appearance and personality, it's impossible to know what your baby will actually look like. But that's part of the fun of expecting a baby.
