Answer:
a) the gametes are TR; Tr; tR; tr for the first parent and the same are for the secon parent
b)1/16 is the chance for the offspring to be ttrr
c) 3/16 is the chance for the offspring to be R_tt
Explanation:
for b) and c) :
RT Rt rT rt
RT RRTT RRTt RrTT RrTt
Rt RRTt RRtt RrTt Rrtt
rT RrTT RrTt rrTT rrTt
rt RrTt Rrtt rrTt rrtt