00:01
Okay, in order to answer this question, let's talk about dominant allelees, okay? remember that if you have one gene, this gene is going to exist in many forms or in different, like, versions of the gene.
00:12
And those different versions of the gene is going to call or are going to be called alias.
00:17
Okay.
00:18
And for example, let's suppose we have only two different versions for this gene, okay, and they are going to be a and a, like in lowercase and capital letter, okay? this is going to be a dominant allele and it's going to be the aggressive elite.
00:33
Let's suppose this dominant a is going to code for yellow hair.
00:44
And the small a is going to code for black.
00:51
So whenever the dominant allele is present in the genotype that is made of two alleles, it means for example in here or here, it's going to give a person with yellow hair.
01:01
And in order to express or for a person to express a black hair, you need to have the two excessive alias in order to have black hair, black hair, okay? so the question says, certain mutations are called dominant negative mutations.
01:17
What do you think this means and how do you suppose these mutations act? but this is question a, okay? let's suppose now that this dominant a codes for a disease, okay? this is a mutant, a mutant allele.
01:34
And the dominant a is the, i mean the recessive a is a normal allele.
01:42
Okay, so practically when you have the presence of this dominant a allele, then you're going to have a disease.
01:49
Person who is going to express disease.
01:50
And what happens when you have the two recessive allele, well, you're going to be normal.
01:55
So a dominant negative mutation gives rise to a mutant gene, a product that interferes with a function of the normal normal gene product causing a loss of function phenotype even in the presence of a normal copy of the gene.
02:08
So for example, normally, like healthy people are going to have this genotype, okay? but what happens when you have this allel here? you're going to have an a or homocygous dominant, okay? and in cases of dominant negative mutations, this, the presence of the dominant aline is going to cause a lot of function of this protein that was called by this genomes...