Answer:
The correct answer is myofibrils
Explanation:
The fundamental part of the muscle cytoskeleton is made up of myofibrils that are the contractile elements of skeletal muscle cells.Muscle fibers are made up of myofibrils, membranes, and cytoskeletal networks that anchor contractile fibrils to the sarcolemma. Myofibrils are composed of repeating contractile units known as sarcomeres and are perhaps the most ordered macromolecular structures in eukaryotic cells. Myofibrils are made up of actin and myosin filaments that are large polymerized protein molecules responsible for actual muscle contraction.
Answer:
B) speciation.
Explanation:
The Galapagos island is known for the different varieties of finches (species of birds) which could be distinguished on the basis of different beak shapes and size.
This is the result of the selection pressure which led to the divergence of the species on the island through a mechanism called adaptive radiation.
Since the adaptive radiation leads to the formation of different species on the same island, the process of formation species is known as the speciation.
Thus, speciation is the correct answer.