Question

why is the microscopy slide shining with a blue light?
you can see the image by clicking the view image button.
a) the high energy blue light initiates the cross - linking of actin and phalloidin
b) the green fluorescent dye attached to phalloidin is excited by blue light and emits green light
c) the blue light has a longer wavelength than the green light; therefore, it excites the fluorophore
d) phalloidin is excited by blue light analogous to dapi

Explanation:

• Option a is incorrect because blue light does not drive cross-linking of actin and phalloidin; phalloidin binds actin directly, and light is for fluorescence excitation.
• Option c is incorrect because blue light has a shorter wavelength (higher energy) than green light, not longer.
• Option d is incorrect because DAPI binds DNA and is excited by UV light, while phalloidin-conjugated fluorophores are excited by blue light to emit green light, so they are not analogous in excitation.
• Option b is correct: Fluorescent dyes attached to phalloidin (used to stain actin filaments) are fluorophores that absorb high-energy blue light, become excited, and then emit lower-energy green light, which makes the slide appear to shine (the observed fluorescence).

Answer:

b) The green fluorescent dye attached to phalloidin is excited by blue light and emits green light