Biology help i'm kind of stuck with this?

Question

Can someone teach me about dominant and recessive and what they mean and anything that has to do with leters like this gg or GG or Gg

can somebody give me a quick lesson i'm very confused.

Answer 1

http://www.youtube.com/watch?v=89Grsrsd_...

Yes i know that the music is very bad but the video just about sums it all up for you

Answer 2

Different forms of a gene are called alleles. Dominant alleles are always expressed in the phenotype. Recessive alleles are only expressed if there is no dominant allele present.

The genotype shows the alleles an individual has for a particular trait.

Dominant alleles are denoted with a capital letter eg G, recessive alleles with the same letter but in lower case eg g.

The genotype in this case could be GG (Homozygous dominant), Gg (heterozygous) or gg (Homozygous recessive).

The phenotype of the individual would exhibit the dominant trait for GG or Gg and the recessive trait for gg.

Hope this helps!

Answer 3

Okay so the best example is plants because they aren't as complex.

If too plants cross with dominant GG and GG the off spring will only have the possibility of GG. same with the recessive gg. and I am sure you have learned the Punnet squares but I will show you a couple anyway.

G g

G GG Gg

g Gg gg

that is how you can shpossibilitiesbitties in a good visual.

crossing Gg and Gg will give three dominant and one recessive.

because the Gg is still dominant like GG.

G g

G GG Gg

G GG Gg

another example. the GG crossed with Gg result in only dominant options.

Hope this helps, sorry if I stated alot of stuff ou already know.

and they are called Genotypes. Genotypes = GG, Gg, gg.

Answer 4

Dominant and recessive genes come in to play during reproduction. I can try to give you an overview (but it's been a while since school, so don't take what I say as definite, but an overview).

For some genes there's a dominant and recessive gene (I believe G is dominant and g is recessive). A good example is genes for the colour of your iris. Brown is a dominant colour (so G), and blue is recessive (so g). If you're genes are GG you have brown eyes, if they're gg you have blue eyes. if you have Gg you should be brown eyed too.

During reproduction you get genes from your parents, so depending on what genes you get, you could have brown or blue eyes. If you have Gg, then because brown (G) is dominant, you should be brown eyed, but since each parent gives only one gene (either G or g, from their own DNA) a child will be brown eyed or blue eyed depending on what they get.

Basically a dominant gene will be the one which shows over a recessive gene, unless the recessive genes are in greater numbers. For example a blonde and brunette couple can have a ginger haired child if each parent has a recessive ginger gene (as the child can have 2 ginger genes, and one of each blonde and brunette)

I'm not convinced that makes a lot of sense reading it back... but hope it helps a little?