Answer:
Open channels allow an influx of sodium ions into the cytoplasm of the muscle fiber. The sodium influx also sends a message within the muscle fiber to trigger the release of stored calcium ions. The calcium ions diffuse into the muscle fiber.
Explanation:
Other molecules such as proteins, starch and sugar are simply too large to diffuse across the membrane. Sometimes, some of these large molecules are transported across the cell membranes by carrier proteins; this does not require energy and as a result is a form of passive transpor
Hair and nails are part<span> of the integumentary </span>system<span>.</span>
Answer:
A) polar
Explanation:
Polar molecules contains partial positive and partial negative charge as in all polar molecules two atoms have unequal sharing electron. Due to unequal sharing of electrons, one atom that attracts valence electrons strongly gains positive charge and other gain negative charge.
For example water, water is a polar molecule having partial negative and partial positive charge because the oxygen atom in water attracts electrons more strongly than the hydrogen atoms.
Hence, the correct answer is "A) polar".
