Genetics Life Science Mr. P

Remember This can be one of the most difficult topics we cover because it is almost all new to you.

You are meeting someone at an airport and you have never met them before. How would you describe yourself so that they know it is you? Think about it

You are meeting someone at an airport and you have never met them before. How would you describe yourself so that they know it is you? Write down a few in the space in your notes…

You are meeting someone at an airport and you have never met them before. How would you describe yourself so that they know it is you? Discuss it with your elbow partner

You are meeting someone at an airport and you have never met them before. How would you describe yourself so that they know it is you? Share your responses

Traits Traits are the physical characteristics of an organism

What does that mean? A trait is different characteristics that a living thing has, such as hair color, eye color, and height.

Traits There are many traits, which are all unique to individuals, but come from your parents

Alleles The different forms of a trait are called Alleles. For example, hair color can be blond, brown, red, black.

Alleles The inheritance of a trait in humans is determined by one or more alleles.

Genes Alleles are based on your genes, which is what your DNA says you are going to look or, in some cases, be like.

Genes Every person has their own genes and they come from both of their parents.

Genes Identical twins have the same genes because they have the same DNA. This is why they look alike.

Genotype Genotype is an organisms genetic make-up

Phenotype Phenotype is the environments’ effect on the genetic make-up of an organism

Genotype vs. Phenotype You may have the genotype for blue eyes and brown eyes, but your phenotype would be brown eyes. This is because you have the alleles for both blue and brown eyes, but you only show brown eyes

Why? Brown eyes are dominant over blue eyes. Some alleles are dominant over others. If you have one allele for a dominant trait, that trait is shown.

What if there is no dominant trait? If there is no dominant trait, then you have the recessive trait. Both alleles (one from each parent) must be recessive in order for that trait to be expressed.

Example One parent has red hair. The other has brown hair. Brown hair is dominant over red hair. The child will most likely have what color hair?

Example Correct! Brown hair! However, this is not always the case, because the parent with brown hair can have the allele for both brown hair and red hair.

Confused?? This can be really confusing which is why we are just learning the terms this week. We will start practicing how to do this next week.

Twin Studies Cloze reading-when I pause, you are going to say the next word. We will stop every now and then for you to read it to your self and to ask some questions /Feature1.asp /Feature1.asp