Name: An Introduction to Mendelian Genetics
Uploaded: 2014-12-12T15:07:46.000Z
Duration: 5 min 10 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

-[Voiceover] An introduction to Mendelian Genetics.

Now before we start, let's review the idea

which contain the DNA that makes each cell unique.

that for each chromosome we have a maternal

on that chromosome that codes for a specific gene

at least two alleles for every specific gene.

One allele from their mother and one from their father.

and we'll start by talking about blood type.

I'm sure that you've heard that blood types

and his alleles both code for blood type A.

and another allele coding for blood type O.

then it's pretty clear that when we check

Now, I'm going to introduce a couple new terms to you.

The first is that since the guy has two alleles

Someone who is homozygous got the same allele

is she going to have blood type A or blood type O?

Well it turns out that she's going to have blood type A

and that's because the A allele is the dominant allele.

While the O allele is the recessive allele.

Since this girl has two different alleles

a mixture of DNA that she got from her parents.

We can describe a person's genes in two different ways.

We can look at the person's individual alleles

We can also look at a person's physical traits

For this guy and girl the phenotype would be

You can see that genotype and phenotype are different

but it is possible for two different genotypes

Since some alleles are dominant over others.

Let's talk about gene inheritance for a bit.

Let's say that our guy and girl from before

We can use something called a Punnett Square

The Punnett Square allows you to determine