Transcript of By: Sebastian Eusse 7°2 The Columbus School 2012-2013.
- Slide 1
- Slide 2
- By: Sebastian Eusse 72 The Columbus School 2012-2013
- Slide 3
- Have you ever wonder how will your children look a like? We can
use genetics to help solve this problem. Genetics is the study of
how traits are passed from a parent to a new offspring.
- Slide 4
- The father of Genetics is Known as Gregor Mendel. Gregor Mendel
was an Austrian monk who presented experiments to help solve this
questions. He used pea plants for his experiments and observed
their traits. Traits are the characteristics that makes us unique.
Like eye color or hair type First Mendel crossed True-breeding
plants which means both parents have the same trait. In the case of
Mendels Experiment the trait was Purple flowers or White flowers.
When Mendel combined flowers of the same color the result was a
flower of the same color. But when he combined flowers of a
different color Mendel saw that all flowers were purple. As a
conclusion Mendel said that purple is a dominant trait and white is
a recessive trait.
- Slide 5
- A Dominant trait is a factor that blocks another genetic
factor. They can be seen When They are standing next to another
dominant trait or when standing next to a recessive trait. A
Recessive trait is a factor that its blocked by the presence off a
dominant factor. They can only be seen when they are standing next
to another recessive factor.
- Slide 6
- There are different types of alleles for an specific trait.
Alleles are the difference forms of a gene. For example the
different alleles for hair type are straight, curly, wavy. Dominant
Alleles can be written with capital letter and a recessive with a
lower case. For example Brown eyes are dominant to blue eyes so
they are written as B and blue as are recessive so they are b. We
get two alleles from our parents, whether is a dominant or a
recessive. When we get two alleles that are the same we know that
as homozygous When we get two different alleles we know it as
heterozygous. There are two types of homozygous. A recessive and a
dominant. Homozygous dominant is when both alleles are dominant,
like BB or SS Homozygous recessive is when both alleles are
recessive, like bb or ss
- Slide 7
- All different letter combinations are all genotypes. Genotypes
are all the different combinations of two alleles. Genotypes are
scene as letter combination. For example if you have brown eyes
your genotype would be BB or Bb. If you have blue eyes it would be
bb. Genotype also determines Phenotype. Phenotype is how Genotype
is physically shown or how a trait appears or is expressed. If your
genotype for eye color is BB your Phenotype is Brown eyes.
- Slide 8
- To help us predict how our children would look, we use punnett
squares. Making a punnett square is easy. First draw a box. Then
draw a line that goes threw the middle of the box horizontally and
vertically. The third step is to put your fathers genotype for a
trait like eye color, on top of the box and your mothers genotype
on the left side. The fourth step is to drag down your fathers
genes to each one of the box, do the same for your mothers. Then
see the what colors you could have had