Gene Expression (1 Viewer)

[Watsername]

Hi, what exactly do we need to know about gene expression?

I know that a gene is fully expressed when its polypeptide is synthesised, converted to a protein and is fully functional and that protein products from genes can make the expression of the gene active or inactive?

also, with multiple alleles, I'm a bit confused becasue I have two different definitions. ones says that it is 'when there are more than two possible alleles in a population, however, only two ever occur in any one individual' and another says is it when a gene has 3 or more alleles. And do we need to know about multiple genes?

 

[The_highwayman]

Multiple alleles is defined as: "ONE GENE having 3 OR MORE alleles (forms of a gene)" thus, u have multiple (many) alleles (forms of A gene)!

I think the other definition just refers to inheritence of multiple alleles. EG: The ABO blood system is an example of multiple alleles but u can only have two of these alleles in your DNA. (AB, AA, AO, BB, BO, OO). Thus, "more than 2 alleles exist in a population (A, B & O) but only two ever occur in any one individual"

As for gene expression, i think u pretty much have the basics...

Enjoy ur study!

 

[lozabella]

multiple alleles....is when a gene has three or more possible alleles for that characteristic...for example the ABO blood groups...u can have an A, B or the absence of either A or B as a genotype..the dotpoint specifically asks for a non-human example....a good one is in dogs
there's four alleles to the S gene which is for coat colour
none is the absence of white spots
P- is piebald spotting
I-is irish spotting
E- is excessive white spotting

 

[seeali]

Hey guys,

just browsing around and i found a question for gene expression..

gene expression is obviously the expression of a gene. as genes code for proteins, those proteins which are polypeptide chains formed in a particular molecular shape, the protein is the expression of that gene..

for example.. there are certain genes that organism have but those genes are switched off as they are not needed.. like in chickens, chickens have the gene to make teeth but because they dont need teeth, that gene is switched off

this is the same with when certain proteins are needed to be formed, the gene that codes for that protein is switched on in order to make that protein and then switched off when the protein is made thus the gene is expressed through the protein

again, its just like there are some genes that exist in our body that are switched off and only get switched on later in life.. for example when we got older some genes like the gene that codes for the alzheimers disease gets switched on therefore causing the disease alzheimers..

i hope that helps it helped me revise over it aswell!

 

[Dr_Doom]

wow I never knew that thing about the chickens.. Thanks