DuckstersDucksters
History Biography Geography Science Games

Science >> Biology for Kids

Biology for Kids

Mendel and Inheritance

What is heredity?

Heredity is when certain traits are passed from the parents to the children. Traits are characteristics such as eye color, height, and athletic ability. Heredity is passed through genes in the DNA molecule. In biology the study of heredity is called genetics.

Gregor Mendel

Scientist Gregor Mendel (1822 - 1884) is considered the father of the science of genetics. Through experimentation he found that certain traits were inherited following specific patterns.

Gregor studied inheritance by experimenting with peas in his garden. Peas work as an excellent test subject as they can self-pollinate, cross fertilize, and have several traits that only have two forms. This enabled Mendel to easily control his experiments and reduced the possibility of the outcomes to something he could record and manage.

Mendel's Experiments

Gregor studied seven traits of the pea plant: seed color, seed shape, flower position, flower color, pod shape, pod color, and the stem length. There were three major steps to Mendel's experiments:

1. First he produced a parent generation of true-breeding plants. He made these by self-fertilizing the plants until he knew they bred true to the seven traits. For example, the purple flowering plants always produced seeds that made purple flowers. He called these plants the P generation (for parent).
2. Next, he produced a second generation of plants (F1) by breeding two different true-breeding P plants.
3. He then produced a third generation of plants (F2) by self-pollinating two F1 generation plants that had the same traits.

Mendel's Results

Mendel found some incredible results from his experiments.

F1 Generation

Mendel found that the F1 generation all produced the same trait. Even though the two parents had different traits, the offspring always had the same trait. For example, if he bred a P plant with a purple flower with a P plant with a white flower, all of the offspring (F1) plants would have purple flowers. This is because the purple flower is the dominate trait.

These results can be shown in a diagram called a Punnett square. The dominate gene is shown with a capital letter and the recessive gene with a lower case letter. Here the purple is the dominant gene shown with a "P" and the white is the recessive gene shown with a "w."

P P
w Pw Pw
w Pw Pw


You can go to this page to learn more about inheritance patterns and Punnett Squares.

F2 Generation

In the F2 generation he found that 75% of the flowers were purple and 25% were white. Even though both parents had purple flowers, 25% of the offspring had white flowers. This turned out to be because of a recessive gene or trait was present in both parents.

Here is the Punnett square showing that 25% of the offspring had two "w" genes causing them to have white flowers:

P w
P PP Pw
w Pw ww


Homozygous and Heterozygous

When two of the genes are the same (like with "PP" or "ww" above) they are called homozygous. When they are different (like with "Pw") they are called Heterozygous.

Interesting Facts about Mendel and Inheritance
Activities More Biology Subjects

Cell
The Cell
Cell Cycle and Division
Nucleus
Ribosomes
Mitochondria
Chloroplasts
Proteins
Enzymes

The Human Body
Human Body
Brain
Nervous System
Digestive System
Sight and the Eye
Hearing and the Ear
Smelling and Tasting
Skin
Muscles
Breathing
Blood and Heart
Bones
List of Human Bones
Immune System
Organs

 Nutrition
Nutrition
Vitamins and Minerals
Carbohydrates
Lipids
Enzymes

Genetics
Genetics
Chromosomes
DNA
Mendel and Heredity
Hereditary Patterns
Proteins and Amino Acids

Plants
Photosynthesis
Plant Structure
Plant Defenses
Flowering Plants
Non-Flowering Plants
Trees
 Living Organisms
Scientific Classification
Animals
Bacteria
Protists
Fungi
Viruses

Disease
Infectious Disease
Medicine and Pharmaceutical Drugs
Epidemics and Pandemics
Historical Epidemics and Pandemics
Immune System
Cancer
Concussions
Diabetes
Influenza


Science >> Biology for Kids


Ducksters Footer Gif with Ducks


About Ducksters Privacy Policy 

 

This site is a product of TSI (Technological Solutions, Inc.), Copyright 2024, All Rights Reserved. By using this site you agree to the Terms of Use.