Genetics

 

Figure 1- shows the crossing of a blue eyed individual and a brown eyed individual

Intro

    Have you ever wondered how you and your parents have same or different features.  Why you have curly hair but your parents do not or why you and your siblings have different eye colors. This is due to a little thing called genetics.Your genes are the code for what traits you will receive from your parents  Gregor Mendel was a well known scientist and teacher who used pea plants to show the sharing of genetics through hybridization.(Olby, 2023) He used yellow and green pea plants to cross hybridization. It showed that genes come in pairs and are inherited as a distinct unit one for each parent. This, also, showed that the offspring got traits in a specific pattern. Hybridization is the crossing of two true breed individuals that have different traits. 

Traits 

   A traits is a variation in the physical appearance of a characteristic that is inheritable. In Mendel's theory one trait was more dominant than others. The more prominent gene was called the dominant gene and the other was called recessive. So when there is a dominant trait shown the recessive trait is hidden.Before Mendel's experiments many people believed that genes was a combination of the two parent genes. However his experiments proved that we have dominant and recessive traits.(Miko, 2008)

Punnett Squares

    Punnett squares are the diagrams we use to predict the genotype of two individuals. The genotype is an organisms genetic makeup and  non expressive alleles like the recessive genes. When you fill out a Punnett square you take the one parents genes and place them on one side of the box and the other parents on the other side. You then begin to cross the different alleles in the boxes. A completed example is shown in both figure 1 and figure 2. Many people have used this idea to help predict whether they will have children with a certain trait or disease likelihood. There is even a whole career field in Genetic counseling that utilizes this tool in order to predict a certain out come for people's offspring.(O'Neil, 2012)

Figure 2 a completed punnet square that shows Mendel's pea plant expirement 

Co dominance and incomplete dominance 

Sometimes the dominant gene does not override the recessive gene. This results in offspring that is a combination of both the dominant and recessive gene. This is where we get co dominance and incomplete dominance. Incomplete dominance is the blending of the two genes in the off spring( ) For example, if you mix a red flower and a white flower and get a pink flowered offspring that would be incomplete dominance. Co dominance is having both colors of the parents on the off spring. So for example, if you used the red and white flower example instead of having a pink flower you would have a red flower with white stripes.( Figure 3)

Figure 3- shows the difference between co-dominance and incomplete dominance

 References

Miko, Ilona. “Gregor Mendel and the Principles of Inheritance.” Nature News, Nature Publishing Group, www.nature.com/scitable/topicpage/gregor-mendel-and-the-principles-of-inheritance-593/. Accessed 6 Nov. 2023. 

Olby, Robert. “Gregor Mendel.” Encyclopædia Britannica, Encyclopædia Britannica, inc., 16 Oct. 2023, www.britannica.com/biography/Gregor-Mendel. 

O’Neil, Dennis. “Probability of Inheritance.” Basic Principles of Genetics: Probability of Inheritance, www.palomar.edu/anthro/mendel/mendel_2.htm. Accessed 6 Nov. 2023.