Question

among birds, some skin cells grow feathers when they mature, while other skin cells grow scales at maturity. which statement best explains this difference?
a skin cells exposed to colder environments grow feathers, while skin cells exposed to wet environments grow scales.
b while all cells have the same dna, specialized cells express certain traits that produce feathers or scales.
c skin cells that have feathers are diploid, while skin cells that make scales are haploid.
d some skin cells have different dna to build structures like feathers and scales.

Explanation:

To solve this, we analyze each option:

• Option A: The environment (cold vs wet) is not the main reason for feather vs scale growth in birds' skin cells. This is incorrect.
• Option B: All cells in an organism have the same DNA. Specialized cells (like those forming feathers or scales) express different genes (traits) from the same DNA. This explains the difference as it's about gene expression, not DNA difference or ploidy or environment.
• Option C: Skin cells in birds are diploid (somatic cells), and the ploidy doesn't explain feather/scale growth difference. Incorrect.
• Option D: All skin cells in an organism have the same DNA. They don't have different DNA to build different structures. Incorrect.

Answer:

B. While all cells have the same DNA, specialized cells express certain traits that produce feathers or scales.