We are searching data for your request:
Upon completion, a link will appear to access the found materials.
Pregnant, you can not wait, finally discover this baby growing in you: will it be big, small? Brown or blond? Will he have the blue eyes of his dad? Your queries partly find their answers thanks to the laws of genetics.
- With his blue eyes, his chin dimple and his mouth that always seems to smile, no doubt, he will look like his daddy! Yet, to look closely, there will also be a little of his mom! Of course, both parents gave him half of his genetic background.
- The heredity, however, is not everything. There are so many parameters involved in the future of an individual that it would be wrong to want to explain everything through the game of genetics. The environment is, for example, involved in the becoming, even physical, of an individual: studies in real twins have confirmed for many years. It remains to know how certain characteristics are determined that make your baby a being, certainly unique, but who looks like you ...
Why does a baby look like his parents?
A baby often has some physical characteristics that do not doubt its origins. And for good reason: he has half inherited the genes of his mother and the other half genes of his dad!
- It is during fertilization that everything is played out : the father brings in his sperms half of his genetic inheritance (carried by the chromosomes), while the mother gives the baby not only half of its genes, but also the environment which will serve as a ground of growth to the first cells of the baby. Then, it is a wise balance between the characteristics of both parents that takes place.
- Every human being has two counterpart representatives from each genecalled allele, carried by pairs of chromosomes: only one allele is transmitted to its offspring. For example, for the gene of hair color, we speak of the blond allele or the brown allele. Some phenotypes (characteristics that genes determine) are called dominant and other recessive: this means that when the chromosomes are reunited after fertilization, one of the alleles concerning the expression of the characters will prevail over the other.
- In the example of hair color, if the dad brings the blond allele and the mother the brown allele, there is very little chance that the child is blond, since the brown phenotype is dominant. It remains that in this lottery, it is impossible to predict what will be transmitted by the parentss because there are a multitude of combinations!
1 2 3 4