How are Traits Inherited
Objectives:
* Investigate how the color of corn kernels is inherited.
* Recognize that an animals’s or a plant’s traits are inherited from its parents.
* Describe how dominant and recessive genes affect inheritance of traits.
What are some traits that these siblings have?
What are some human physical traits?
Physical characteristics are defining traits or features about your body. The first thing you see when you look at someone could be their hair, clothes, nose, or figure.
These are all examples of physical characteristics.
Gregol Mendel
Gregol Mendel was a German-speaking Moravian scientist and Augustinian friar who gained posthumous fame as the founder of the modern science of genetics.
Though farmers had known for centuries that crossbreeding of animals and plants could favor certain desirable traits, Mendel's pea plant experiments conducted between 1856 and 1863 established many of the rules of heredity, now referred to as the laws of Mendelian inheritance.
Mendel worked with seven characteristics of pea plants: plant height, pod shape and color, seed shape and color, and flower position and color. With seed color, he showed that when a yellow pea and a green pea were bred together their offspring plant was always yellow.
However, in the next generation of plants, the green peas reappeared at a ratio of 1:3. To explain this phenomenon, Mendel coined the terms “recessive” and “dominant” in reference to certain traits. (In the preceding example, green peas are recessive and yellow peas are dominant.)
He published his work in 1866, demonstrating the actions of invisible “factors”—now calledgenes—in providing for visible traits in predictable ways.
Mendel's Experiment
Dominant and Recessive Factors
The terms dominant and recessive describe the inheritance patterns of certain traits. That is, they describe how likely it is for a certain phenotype to pass from parent offspring. Sexually reproducing species, including people and other animals, have two copies of each gene.
Dominant: When an organism has a dominant factor for a trait from either parent, the trait will show up in the offspring.
Recessive: An organism will only have a recessive trait if it receives that factor from both parents.
Click here for additional Dominant and Recessive Explanation
Dominant and Recessive Factors examples:
Punnet Square
The Punnett square is a diagram that is used to predict an outcome of a particular cross or breeding experiment. It is named after Reginald C.Punnett, who devised the approach. The diagram is used by biologists to determine the probability of an offspring having a particular genotype.
Lesson 4: Guide Questions
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