Question: @All scientists Why do we inherit features from our parents?

Thomas Clements answered on 17 Mar 2015:

Hi Adam,
Basically all the genetic information our cells need on how to function, grow and make new cells is stored in our chromosomes. We all have 23 chromosomes in each cell. Each chromosome is part of a pair and this is really important:

During reproduction, the male produces a sperm cell, which contains 50% of his genetic material; one of each of the chromosomes required to make pairs. The mother’s egg cell also has one of each chromosome (50% of her genetic material). When these meet, the chromosomes can then be successfully paired, so the child will have 50% of their genetic information from each parent.

This is really important because chromosomes each carry genes, which are the instructions a cell requires to do it’s job. Although the individual genes will do the same job, sometimes they can be slightly different forms of the same gene – called alleles. This is important because some alleles are more ‘dominant’ than others.

Lets think of an example: eye colour.

My father has blue eyes but my mother has brown. Each gave me 50% of their genetic information, so I have the genetic instructions (gene allele) to have either blue or brown eyes. BUT, the brown eyes are the dominant allele, so it is much more likely for me to have brown eyes.

This is why we often share traits with family members but we often have a mixture of features: in real life everyone always says I have my mother’s big ears and my fathers big nose. I have the same hair colour as my mother but my brothers share my fathers hair colour.

This website explains it really well and even has a genetic game to play: http://genetics.thetech.org/