What is true breeding?

[MissionCO]

Hi,

I am a little confused what true breeding is.

Is it something like this: RR x RR or RR x rr


Rr x Rr is a mono hybrid cross, and RrBb x RrBb is a dihybrid cross correct?

[JackBean]

True breeding means that all offspring has the same phenotype as parents. This is possible only with homozygotes, i.e. RR × RR; rr × rr, but also RRbb × RRbb, rrBBFF × rrBBFF etc.

[MissionCO]

So my 1st example

RR x RR

or rr x rr this is true breeding?

Not RR x rr correct?

RR x rr would be a mono hybrid right?


Thank so much.

[JackBean]

I think that in definition of true breeding it says: when bred with itself", so it should always be the same genotype for both