A dihybrid plant with incomplete linkage on test cross may produce how many types of plants?
1) 2
2) 4
3) 8
4) 1

There would be four types of plants produced by performing a test cross between a dihybrid plant showing incomplete linkage.
Suppose, a heterozygous tall plant with round seeds (TtRr) is test crossed with homozygous short parent with green seeds (ttrr). The cross is as follows:

Gametes: TR, Tr, tR, tr     and   tr

Progeny:

	TR	Tr	tR	tr
tr	TtRr	Ttrr	ttRr	ttrr

Hence, the correct option is (2).