Question

The fact that nucleus possessed the ability to control phenotype was first determined by

• A. Experiments with radiolabelled phages
• B. Experiments with bacteria that identified DNA polymerase
• C. Transformation experiments with Streptococcus pneumoniae
• D. Identification of restriction endonucleases
• E. Grafting experiments with Acetabularia

Answer 1

The correct option is E Grafting experiments with Acetabularia

Acetabularia consists of a rootlike holdfast, a long, cylindrical stalk; and a cuplike cap. The nucleus is present in the holdfast. Acetabularia exhibits regeneration of the cap after any injury. A. mediterranea has a smooth cap and A. crenulata, has a cap with fingerlike projections. Danish biologist J. Hämmerling and Belgian biologist J. Brachet performed grafting experiment on above mentioned species and showed that type of caps that regenerated were determined by the type of the donor species of the holdfasts, not by those donating the stalks. It was concluded, that nucleus in the holdfast of Acetabularia controls the shape of the caps. The correct answer is E.