Question

Differentiate between Pr form and Pfr form of phytochrome.

Answer 1

• Pr form is an inactive form of phytochrome which has maximum absorption in red region, whereas Pfr form is an active form of phytochrome which has maximum absorption in far-red region.
  
• Pr form absorbs red light and gets converted into Prf form whereas Pfr form absorbs far-red light and gets converted into Pr form.
  
• Moreover, Pr form is found in diffused state in cytoplasm, whereas Pfr form is found in association with dense cytoplasmic body.