Dihybrid Crosses Question Help Please!

1. Male TTBb is crossed with female Ttbb
a) What is the male's genotype?
b) What is the female's phenotype?
c) What are the male's gametes?
d) What are the female's gametes?
e) Genotypic ratio?
g) Phenotypic ratio?

I understand a and b! But for c and d, when it comes to gametes does it mean like ( TT ) or just T?

I'm not sure if you've learned about the FOIL method in math, but it means first inner outer last. If you have something like (a + b)(c + d) you'd multiply the first two in each set (ac) the inner two (bc) outer two (ad) and last two (bd) to ensure you covered all pairs. You do the same when trying to find out the gametes. Your pirst trait is like the first set of brackets, and the other trait is like the second. Both alleles have to be represented in each gamete.
TT Bb

Gametes: TB TB Tb Tb

If it was AaDd, you'd have AD, aD, Ad, ad

the females gametes are done in the same way. Ttbb = Tb tb Tb tb.
Then you make a 4x4 punnet square. Put all the females gametes accross the top, and the males along the side (or vice verse). Figure out the ratios from there.

Hope this helps!

Andrea's answer is completely correct. However, you can make your Punnet square smaller if you recognize that the male really can only produce 2 kinds of gametes: TB and tb. Likewise, the female can also produce only two kinds of gametes: Tb and tb. So, you really only have to do a 2X2 Punnet square.

treeretr