In the initiation of muscle fiber contraction, calcium ions bind to tropomyosin, exposing active sites on actin for cross-bridge formation. a. true b. false

During a fierce storm a large number of tall trees on an island are uprooted by the wind and die. most of the trees on the island are now short trees and produce seeds that grow into short trees. what concept is shown in this example? question 5 options: natural selection artificial selection genetic engineering gene splicing