Answer and Explanation: First cross is between homozygous: LLBB x llbb.
Homozygous individuals produce one type of gamete:
So, F1 progeny will have genotype : LlBb
Second cross is between the F1 progeny in a testcross. A testcross is a genetic cross between a homozygous recessive individual and a suspective heterozygous genotype to determine the latter.
So, second cross is: LlBb x llbb
As said before, homozygous will produce only one type of gamete: lb
For heterozygous individuals, and one that exhibits recombination, will produce 4 types of gametes: