Genetics and Chromosomal Influences
Genetics and DNA
Have you ever wondered where you got your blue eyes? Where in the world did you get such big feet? Of all the members of your family, why are you the one who has thin hair? Well not only are your parents responsible, but your ancestors from centuries ago can be responsible too. Recessive genes are not as obvious, however can be carried from generation to generation until it eventually shows up in a child many years later.
Each of us has chromosomes. Chromosomes are thread like substances made up of protein and deoxyribonucleic acid (DNA). They can be found in the nucleus of each cell in our bodies. The chromosomes help keep the DNA tightly tied together as we build new cells to replace the old cells that we shed.
Normally, humans have 23 pairs of, or 46 total, chromosomes in their DNA strands. However, there are genetic diseases where there are more chromosomes present, as in Down syndrome, or fewer chromosomes in the case of Turner syndrome.
Baby has 50/50 Chance for Blue or Brown Colored Eyes
Dad has 1 b Mom has 1 B
Dad has 1 b Mom has 1 b
Baby has Brown Eyes
Baby has Blue Eyes
Dominant and Recessive
Usually, darker genes are the dominant genes. If both parents have light eyes, the children will almost always have light eyes as well. However, if only one parent has dark eyes, the chances of the children having dark eyes are much more likely depending on the eye color of the grandparents. The same works for those with dark hair versus blonde or red hair.
The baby in the picture to the right has one parent with blue eyes, her father. He must have two recessive chromosomes in order to have the blue eyes (bb). Her mother has brown eyes. She carries the dominant gene. However, the mother is a product of one parent with blue eyes and one with brown. Therefore, she carries a recessive blue eyed chromosome, even though it isn’t visible (Bb). Because of the hidden recessive blue eyed gene carried by her mother, this baby had a 50/50 chance of having the gorgeous brown eyes she has.
The determination of the gender of the child is determined by the father based on the same rule. Each person has an "X" chromosome. Females have an additional "X" and males have a "Y" chromosome. If the contribution of the father's gender chromosome is an "X" the baby will be a girl. If it is a "Y" the baby will be a boy.
The way a person behaves, feels, and looks isn’t always based on genetics. Environmental influences are mimicked by children. For example, facial expressions and speaking with accents can be inherited by adopted children. Granted, the genetic possibility of color, shape, or appearance of the body, hair, and face isn’t there. Still, you may find that quite often, an adopted child will begin to look like one or both parents because of the exposure to the parents’ mannerisms.
What would normally be genetically inherited talents such as singing, dancing, playing sports, or telling jokes, may be learned talents by the adopted child. Thus, these talents are perceived as continuing to “run in the family.”
An Example of an Environmentally Learned Trait
I certainly hope this article was helpful and entertaining. Your opinion is greatly appreciated, so please feel free to leave a comment, suggestion, or constructive criticism in the comments section below.
"Be kind to one another" ~ Ellen
God Bless You ~ Margaret Sullivan