Following statements were made regarding gibberellins (GA) biosynthesis in plants and fungi:
A. Two separate enzymes are involved in synthesis of ent-kaurene from GGDP in plants.
B. Only a single bifunctional enzyme catalyzes the synthesis of ent-kaurene from GGDP in fungi.
C. GA-biosynthesis genes are mostly clustered on a single chromosome in fungi.
D. GA-biosynthesis genes are randomly located on chromosomes in fungi.

Which one of the following combinations of statements is correct?

Correct option is A

Explanation-

A. Two separate enzymes are involved in synthesis of ent-kaurene from GGDP in plants - True 

In plants, two separate enzymes (ent-copalyl diphosphate synthase and ent-kaurene synthase) are involved in the conversion of GGDP (geranylgeranyl diphosphate) to ent-kaurene.

B. Only a single bifunctional enzyme catalyzes the synthesis of ent-kaurene from GGDP in fungi - True 

In fungi, this reaction is catalyzed by a single bifunctional enzyme that performs both steps.

C. GA-biosynthesis genes are mostly clustered on a single chromosome in fungi - True 

In fungi, the GA-biosynthesis genes are mostly clustered together on a single chromosome, often forming a gene cluster.

D. GA-biosynthesis genes are randomly located on chromosomes in fungi-  False

This contradicts statement C. In fungi, the genes are not randomly located; they are clustered.

Correct option: a -  A, B and C only