Science Kids at Home
Science Gifts for ChildrenScience Experiments for Children
 
Web sciencekidsathome.com

Genetics - What are Genes?

Kids like asking questions about science. Find out about genetics, what are genes and why parents with brown eyes have a child with blue eyes.

Kids Science Trivia Questions

  1. Why is DNA described as the “double helix of life”?
  2. Where are chromosomes found within a living cell?

Find the answers to these kids science questions.

Continue reading "Genetics - What are Genes?"

 

Subscribe for your FREE monthly
Kids Activities Newsletter and we'll send you a link to our Kids Activities Library filled with kids crafts ideas and science projects to keep your children happy and busy!



Privacy Policy

We'll never share your email ID with anyone.
Creative Kids at Home NewsletterAdd the Creative Kids blog to your RSS reader.

 

 

 

Genetics - What are Genes?

Inside every cell of each living thing (plant or animal) are sets of instructions called genes. The genes provide the instructions on what is the plant or animal, what it looks like, how it is to survive, and how it will interact with its surrounding environment. The genes are strung together in long stands of material called deoxyribonucleic acid (DNA) and these long strands are called chromosomes. Most living things have pairs of chromosomes (one from each parent), though they may have a different number of chromosomes from another living thing. For example, humans have 23 pairs of chromosomes and the fruit fly has 4 pairs.

Each gene is made up of long combinations of four different nucleotide bases. It is the various combinations of the nucleotide bases that determine everything about a living creature.

The four nucleotides are called:

  • adenine(A),
  • cytosine (C),
  • guanine (G), and
  • thymine (T).

The gene for green eyes might have this nucleotide sequence.

AAACCGGTTTTT

The gene for blue eyes might have this nucleotide sequence.

AAACCGGTTTAA

Notice how the nucleotide sequences below are very similar. The only difference being the last two bases. They both describe an eye with the last two characters stating the color of the eye.

Note: These gene formula are not accurate, the correct sequence could be up to several thousand bases long).

Many of the genes have a quality known as Dominate or Recessive. Dominant traits are more common than Recessive traits due to this quality.

Why do I have blue eyes when both my mother and father have brown eyes?

Each person has two genes for eye color. When a person has two identical genes, he will have eyes of that color. Another person may two different genes, and she will have eyes the color of the dominant gene. With eye color, the gene for brown eyes is dominant (B). The gene for Blue eyes is recessive (b). If a person has one B gene and one b gene or two B genes, then that person will have brown eyes. If a person has bb eye genes, then the person will have blue eyes.

Parents with Brown Eyes and Recessive Genes

Parents with Brown Eyes and Recessive GenesIn this diagram, both the mother and father have brown eyes, but they both have the recessive gene for blue eyes as part of their genetic makeup. There is a 1 in 4 or 25% chance that their child will have blue eyes.

One Brown Eyed Parent with Recessive Gene

One Brown Eyed Parent with Recessive GeneIn this diagram, the mother has brown eyes with the recessive blue eye gene and the father has blue eyes. There is a 1 in 2 or 50% chance that their child will have blue eyes.

Brown Eyed Parent without Recessive Gene

Brown Eyed Parent without Recessive GeneIn this diagram, the father has blue eyes and the mother has brown eyes without the recessive gene. In all of the possible combinations for the children, there is one of the dominant B genes. All of the children will have brown eyes.

The results would be the same in diagram 2 if the Mother had blue eyes and the Father had Brown eyes with a recessive blue gene, or in diagram 3 if the Father had the brown eyes and the Mother had blue eyes.

Word Definitions

  • Dominant - a gene in one strand of DNA that is stronger than the corresponding gene in another strand of DNA.
  • Recessive - a gene in one strand of DNA that is weaker than the corresponding gene in another strand of DNA.
  • Trait - a distinguishing feature in a person.

Trivia Answers

1.  Why is DNA described as the “double helix of life”?

Double is from the two strands of DNA.  A helix is anything spiral in shape or structure.  The DNA is found in two spiral strands.  Without the DNA, there would be no life.

2.  Where are chromosomes found within a living cell?

The chromosomes are found in the nucleus of each cell.

Interesting Website for kids science on Genetics

DNA Workshop



Find more Science Topics

More information and science experiments about:

Notes to Parents:

  1. Every parent must use their own judgment in choosing which activities are safe for their own children.  While Science Kids at Home makes every effort to provide activity ideas that are safe and fun for children it is your responsibility to choose the activities that are safe in your own home.
  2. Science Kids at Home has checked the external web links on this page that we created.  We believe these links provide interesting information that is appropriate for kids.  However, the internet is a constantly changing place and these links may not work or the external web site may have changed.  We also have no control over the "Ads by Google" links, but these should be related to kids science and crafts.  You are responsible for supervising your own children.  If you ever find a link that you feel is inappropriate, please let us know.

send email to Science Kids at HomeSend us a note if you have any questions.

 

Kids Science Gifts  Science Experiments  Science Fair Projects  Science Topics  Creative Kids Blog

Kids Crafts  Privacy Policy  Copyright © 2011 Science Kids at Home, all rights reserved.