It permits calcium to leave the sarcoplasmic reticulum and enter the cytosol. During muscle contraction, the binding of acetylcholine initiates an excitatory impulse, which is transmitted to the deep of the muscle via T tubules. T tubules are the invaginations of cell membranes of muscle cells (sarcolemma). When the action potential travel down the t-tubules, they change shape and allow the calcium ions to enter into the sarcoplasm from the sarcoplasmic reticulum.
Answer:
D. Ticks live on and drink blood from a cow.
This is an example of parasitism, where the ticks (parasite) are living off of the blood of the cow, the host animal.
Explanation:
Parasitism is a relationship between organisms. In this relationship, one organism (parasite) lives on or in another organism (host) and gains benefits from the host, causing it some harm.
Parasites are classified as ectoparasites, which live on the body surface of the host (ticks, fleas, leeches, and lice) and endoparasites, which live in the body of the host. Endoparasites are either intercellular, which live inside the host’s body (round worms, tapeworms) or intracellular, which live inside the cells in the host’s body (bacteria or viruses).
Parasites help to control dominant species and has a role in evolution by transferring genetic material between species.
MRNA is the RNA that assists in Messaging the DNAs instructions to the ribosomes (sites of protein synthesis). tRNA helps to transfer the necessary amino acids to the ribosomes. In short, mRNA tells the ribosomes what amino acids to use and in what order. tRNA “retrieves” those and bring later them to the ribosomes.
The right answer for the question that is being asked and shown above is that: "TRUE." The wide variety of organisms present in coral reefs and their complex relationships make coral reef preservation an important priority.
Answer:
Explanation:
Normally, two distinct sounds are heard through the stethoscope: a low, slightly prolonged “lub” (first sound) occurring at the beginning of ventricular contraction, or systole, and produced by closure of the mitral and tricuspid valves, and a sharper, higher-pitched “dup” (second sound), caused by closure of aortic
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