The basic structure of a muscle fiber is comprised of actin and myosin protein chains that straddle each other in a fusiform arrangement. The actin and myosin arrays interlock and move past each other to cause contraction of the muscle. They then move back to their initial positions in relaxation. This gives muscles their elasticity and distensibility. The muscle fibers are bundled, in their 10s to 100s up into myofibrils around an endomysium. Many myofibrils are also bound up in a perimysium to form a muscle fiber.
Enzymes speed up all of the reactions that happen inside cells. They help with digestion and our metabolism. Enzymes can do a few different things like:
Break up big molecules into smaller pieces, so they can be absorbed more easily by the body.
Enzymes also are very picky catalysts, and will only “speed up” certain types of reactions.
Hope this helps you!! (:
Answer:
A. Haploid (n)
Explanation:
Conifers do not exhibit double fertilization that forms triploid (3n) endosperm in flowering plants.
Endosperm in conifers develops from the haploid cell of female gametophyte before fertilization. Since the endosperm is formed by the mitotic divisions in the haploid cell (n) of female gametophyte, it is haploid (n) in nature.
Answer:
gravity is your answer my friend
Answer:
a
Explanation:
called Pangaea (meaning "all lands"), and over time they have drifted apart into their current distribution. He believed that Pangaea was intact until the late Carboniferous period, about 300 million years ago, when it began to break up and drift apart.
