Question

multiple choice
02:50
what causes the real curl in a bighorn sheeps horns?
this question is worth 2 point(s)
the horns are shaped by wind and weather.
the sheep twist their heads often.
the protein on the outside grows faster than the inside.
the horns are bent during fights.

Explanation:

Bighorn sheep's horn curl is due to differential growth. The outer protein (keratin) grows faster than the inner part, causing the curl. Wind/weather (A) affects erosion, not curl. Head - twisting (B) and bending during fights (D) don't cause the natural, consistent curl seen in their horns.

Answer:

C. The protein on the outside grows faster than the inside.