Question

Sudan Red dye stains primarily waxy, hydrophobic material. A root is soaked in Sudan Red and analyzed for stain retention. What is a scientist observing sections of the root under a microscope likely to see?

a) Blue granules indicative of starch
b) Death of cells and abscission
c) Stained waxy, hydrophobic material
d) Increased exposure to light

Answer 1

A scientist is likely to observe stained waxy, hydrophobic material in the sections of a root that has been soaked in Sudan Red, indicating the presence of lipids in certain cell types such as the cortex, xylem, and phloem.

Step-by-step explanation:

When a root is soaked in Sudan Red, a scientist observing sections of the root under a microscope is likely to see stained waxy, hydrophobic material. Sudan Red dye preferentially stains lipid-rich areas because of its affinity for hydrophobic components. For example, the cells in the cortex, which contain mostly lipid droplets, will show a deep stain. Similarly, the tracheids in the xylem and the sieve elements in the phloem may also show staining due to the presence of transported oil droplets. This type of staining helps scientists differentiate cell types and understand the distribution of lipids within plant tissues.