|Author: Gaurav 09 Sep 2016 Member Level: Silver Points : 3 (Rs 3) Voting Score: 0|
Just like skin colour, height is also governed by polygenic inheritance and a lot more factors influence height such as growth hormone secretion, protein retention, calcium retention etc. some genes are also known to show pleiotropic effect( one gene can influence the other) and thus could have a positive/negative effect on height of the individual. Children traits are inheriteded from both parents. They get 50% from the father and 50% from the mother. All the genes in combination, make up the resulting human. There are very few traits that are onlyinherited from one parent. It is very specific stuff like being male, you inherit that from your father if you get the Y chromosome.There are also a few other sex chromosome linked genes that will be from only one parent in male children. For a few genes there is also parental imprint, but that is usually not easy to see in the resulting child. Height is influenced by multiple genes. We can use the parents heights to calculate a child's target height-the height that we would expect the child to attain-but it is just an educated guess. Different ethnic groups tend to be taller or shorter. Occasionally, a mutation in a single gene can strongly affect growth. Although genetics has powerful effect on growth, it is just half the story. The other half is the environment,that is, the circumstances in which the child is raised.
Hope it will clear your doubts.
|Author: [Anonymous] 09 Sep 2016 Member Level: Diamond Points : 4 (Rs 4) Voting Score: 0|
We have 23 pairs of chromosome and each chromosome bears lots of genes which codes for different characteristics for us. Among these 23 pairs, 22 pairs are known as Autosomes which are same (in terms of characteristic they code for) in both males and females and 23rd pair is known as sex chromosome which is different for both male and female.
So the physical characteristics are taken forward to the next generation by autosomes and the features like skin color, hair color, height, eye color, etc,. are coded by these chromosomes only.
When a child takes birth by the combination of chromosomes from both father and mother, the traits can be visible on any of them depending upon the dominating trait. It means, every gene as both the traits. For example- we have code for dark skin color as well as light skin color, but what is trait coding is of dominating code.
For example- a boy's father is tall and mother is of average height, it means mothers gene coding for average height is dominating and father's gene for good height is dominating. During fertilization, which ever gene gets combined and become dominating will decide the boy's height.
We know all these facts are scientifically established.