Genetic Screens Found Two Types of Gibberellin-Insensitive Mutant Strains: Excessively

question 172

Multiple Choice

Genetic screens found two types of gibberellin-insensitive mutant strains: excessively tall plants and dwarf plants.These mutations affected _______ protein(s) , a(n) _______ of a transcription factor.In the excessively tall plants, the growth-promoting genes controlled by gibberellin are always switched _______, whereas in dwarf plants they switched _______.

• A) different; repressor; off; on
• B) the same; activator; on; off
• C) different; repressor; on; off
• D) the same; repressor; on; off
• E) different; activator; off; on