Which one of these pictures is the answer to this?

Pretty sure its the picture with "R" ?

A monohybrid cross punnett square that is a cross of an idividual who is heterozygous dominant and an individual who is homozygous recessive.

which punnet square represents this? or is it not either one? Pretty sure its the first one?

Thanks!

hmmmm actually i think its neither of these?


wouldnt it be a cross between Rr and rr?

which would produce:

Rr
Rr
rr
rr

right?

The one with the r's would be correct, except that dominant alleles are typically depicted a capital letter, and recessive with a lowercase. So if the representation of upper and lowercase letters were switched, it would be correct.
I'm awesome, so I drew it out for you:

That is a truly correct answer.

ok thanks! yeap , i drew it similar except i put the two lowercase r's on top, and the Rr on the left. would that still be okay to draw it like that?


also, if R is brown hair, and r is blond hair.

brown is dominant and blond is recessive. what would be the resulting pheonotypes? thanks.

and if asked what are the resulting genotypes, well isnt that exactly what the punnett square is showing?

This post was edited by noob_whacker on Nov 5 2013 05:33pm

Yup, you can put the alleles on the outside in whichever order you'd like.

There would be two phenotypes as a result: Brown hair and blonde hair.
I'm assuming you need the probability of each one. So since in these problems an dominant allele completely overrides a recessive allele, any genotype which contains an dominant allele(RR, Rr) will result in brown hair. Any with two recessive alleles(rr) will result in blonde hair. So there is a 50% chance of getting brown hair, and a 50% chance of getting blonde.
And yes, the punnett square is showing the genotypes that can result from it, and the probability would be 50/50 for Rr and rr.

This post was edited by weslee on Nov 5 2013 05:37pm

thanks. got two other questions left if u dont mind helping


ops blurry....

well it says for another monohybrid cross, C is height. Tall dominant is C and short recessive is c.

cross between individuals who are both heterozygous dominant for the trait.

what is the genotype of each individual? what is the phenotype?

and what are the resulting genotypes?


pretty sure the genotype of each individual is Cc? and then the phenotype of each individual is Tall.

The resulting genotypes would be 100 percent Tall? or 75 percent tall and 25 percent short?


and the second question is:

a dihybrid cross.... eye color is letter K with brown eyes as dominant and blue eyes recessive.

hair color is letter R. brown hair is dominant and blond hair is recessive.

if the dad is homozygous recessive for eye color (blue eyes) and heterozygous dominant for hair color (brown hair).

List the four possible combinations of alleles the dad could contribute?

and... if the mom is homozygous dominant for eye color (brown eyes) and homozygous recessive for hair color (blonde hair) then what is her genotype?

and figure of the four possible cobinations of allels the mom could donate?

thanks

second question is hard lol


This post was edited by noob_whacker on Nov 5 2013 05:56pm

Heterozygous dominant means that the genotype has one dominant(capital) and one recessive(lowercase) allele, so Cc.
http://imgur.com/PLZF16z
So 75% of them will be tall, 25% short. Genotype ratios are evident from the picture.

Working on the second part.

This post was edited by weslee on Nov 5 2013 06:09pm

thanks! do u know the 2nd question part? that part im most lost on


edit: oh ok thanks!

got from somewhere else that the father contributes kR, kR, kr, kr?


This post was edited by noob_whacker on Nov 5 2013 06:12pm

So this question appears to just be asking you for every genotype each parent could contribute, not asking for a punnett square.
So we'll start by writing out the full genotype of each parent. Just think of the genotype for each trait than combine them, so:
Father: kkRr
Mother: KKrr

We know that each parent must donate one allele for eyecolor, and one allele for hair color. So each combination they contribute will contain one K/r(allele for eyecolor) and one R/r(allele for haircolor).
Therefore the dad could potentially contribute Rk or rk.
And the mother can contribute only Kr.