Hair and nails are part<span> of the integumentary </span>system<span>.</span>
Valves ensure blood flows toward your heart. Vein valves work to bring the blood that flowed down via arteries back up to your heart.
The stem cells will divide through mitosis to create diploid stem cells.
The correct answer is B.
A food web typically start with a plant which serves as the primary producer of food for the other living organisms that are in the food web. The food web is made up of many tropic level, only about 10% of the energy in one tropic level is transferred to the next trophic level.
Looking at option B, you will discover that the food web start with a plant which is mangrove. Insects feed on mangrove, southern leopard frog feed on insects and raccoon feed on American alligator.
The human body comprises of more than 600 muscles differentiated in three classifications, and all are under the control of the nervous system. The activities like picking up a dropped pen or leaning over incorporate the combined effort of various muscle groups.
The alert mind relays this instruction to the central nervous system that conducts it in the form of electrical impulses. These are then mediated via the somatic segment of the peripheral nervous system to the nerves accountable for monitoring the essential muscles.
When the signals arrive, a chemical known as acetylcholine gets discharged from the nerve terminals, activating the membranes of muscle fibers and making them to contract. The receptors present in the muscles provide the brain with the instruction regarding the movement and position of the body, the brain monitors the contraction of skeletal muscles.