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Name: Juan
Status: other
Grade: other
Location: Outside U.S.
Country: Guatemala
Date: Winter 2012-2913

What are the probabilities that a women inherits her mother's or her father's physical constitution?


To put this into simplest terms, for every gene, one allele (trait) comes from Mom and one allele comes from Dad, which is a 50/50 chance. Genes can be dominant or recessive or a mixture of one dominant and one recessive trait, which means the possibilities vary. If Mom and Dad are both carrying a recessive allele, their child might not look like them. Genetics is a little more complicated with the possibility of genes being expressed or not. There are many genes that control traits like height, hair, eye and skin color. That is the reason when a baby is born, we might see a resemblance to another relative. If your family carries a genetic disease that you are concerned about, it would be best to go to a genetic counselor and inquire about the odds.

Sincerely. Judy Luke

Hi Juan,

Thanks for the question. However, the question is vague (to me at least). By "physical constition" are you referring to a physical trait (e.g., hair color), DNA, or an inherited disease (e.g., cystic fibrosis)? If you could let me know more, I am can answer your question better.

Thanks Jeff


The only characteristics you inherit are from your parents. Your Mom and your Dad are the only source of your physical traits. In the very very early stages of development, when sperm first meets egg, your Dad contributes half of the genes and your mother contributes the other half. That is a solid event, but there are very very many other influences going on that cause some genes to express themselves and other genes to be recessive. For example, brothers and sisters, although they have the same parents, don’t turn out to be the same. In fact, even twins born of the same egg that split while similar in many respects are still different in other aspects of their lives. So each and every human being is the product of their Mom and Dad’s genes, but other mechanisms intervene to cause “variations” among people.

The scientific subject you want to study more for the answer to your question is epigenetics. Please see this on-line:

The best book I have found is: The Epigenetic Revolution by Nessa Carey ISBN 978-0-231-16116-9

Sincere regards, Mike Stewart

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