A researcher has a plant that displays yellow flowers, the trait dominant over white flowers in the species. How might the researcher discover if his plant is heterozygous or homozygous yellow?

Question

the_ocean_girl · Answer

@malcolmmcswain

malcolmmcswain · Answer

I am concurrently playing chess with dan, so answers may not be complete. Have you studied heredity before?

the_ocean_girl · Answer

Yes but I'm not very good at it

malcolmmcswain · Answer

Ok, so let's start with dominant and recessive traits.

malcolmmcswain · Answer

Do you understand the gist of that? Like the punnett square and all?

the_ocean_girl · Answer

yep

malcolmmcswain · Answer

Ok. So, let's look at these two different zygosity types.

heterozygous:
A diploid organism is heterozygous at a gene locus when its cells contain two different alleles of a gene. The cell or organism is called a heterozygote specifically for the allele in question, therefore, heterozygosity refers to a specific genotype.

homozygous:
Alternative forms of a given gene are called alleles, and they can be dominant or recessive. When an individual has two of the same allele, whether dominant or recessive, they are homozygous. Heterozygous means having one each of two different alleles.

Do you understand all this?

the_ocean_girl · Answer

Yes I do

malcolmmcswain · Answer

Ok, so how might a researcher be able to tell the difference between the two different zygosity types when looking at the color of a yellow flower?

the_ocean_girl · Answer

I don't know. I always get tricked up on figuring out genotypes based on phenotypes

malcolmmcswain · Answer

An organism can be homozygous dominant, if it carries two copies of the same dominant allele, or homozygous recessive, if it carries two copies of the same recessive allele. Heterozygous means that an organism has two different alleles of a gene.

So, the two alleles are:

white pigment - recessive

yellow pigment - dominant

What does this tell you about how this might affect the color of the flower?

malcolmmcswain · Answer

http://prntscr.com/9bh49l - LOL

the_ocean_girl · Answer

Child you have me beyond confused now

the_ocean_girl · Answer

@TheSmartOne anything? This question has me really confused >.<

thesmartone · Answer

You need to tell us where you are confused at.

And it seems that @malcolmmcswain has this under control. :)

malcolmmcswain · Answer

Sorry, only half-here. What don't you understand.

the_ocean_girl · Answer

I understand everything until it gets to whether it's hetero or homozygous. It doesn't tell the parents or anything else so how can I determine if it's hetero or homozygous.

malcolmmcswain · Answer

Homozygous - has two copies of either dominant or recessive
Heterozygous - has a copy of both dominant AND recessive

So, w = white pigment, Y = yellow pigment

Homozygous -

YY or ww

Heterozygous -

Yw

malcolmmcswain · Answer

Try to see what colors the flowers might be if they had these gene pairs