Answer:
a. enclosing their DNA in a nucleus.
Explanation:
Prokaryotes in general have no membrane bound organelles. The cells are enclosed in a plasma membrane though .
A. Earth's magnetic field reverses over time; the changes show that seafloor spreading has taken place over time.
Explanation:
The pattern of the magnetic minerals in seafloor ridges are aligned in a repeating pattern because the earth's magnetic field reverses overtime.
This provides evidence because the changes shows that the sea floor spreading has taken place over time.
- The concept of sea floor spreading was first suggested by Harry Hess in the early 1960's.
- Using sophisticated tools, he was able to discover stripe patterns of magnetic minerals in rocks.
- The earth can be likened to a giant bar magnet
- The geomagnetic field originates from the core where the movement of molten metals induces magnetism.
- In a fresh cooling magma, the metallic minerals are able to align their domains with the prevailing magnetic field.
- At some point the magnetic field is normal with a very strong intensity. At other times the intensity is low and it reverses.
- The minerals keeps track of the changes.
- This leads to striped pattern that has been used to suggest sea floor spreading.
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In order to actually start up the Scientific method you must "Observe" whatever it is you want to question.
The development and dissolution of cross-bridges connecting myosin head binding actin ratchet the thin and the thick filaments past one another in response to nervous system motor output. The muscle fibers get shorter as a result of this sliding movement since the filaments are anchored.
<h3>Briefing:</h3>
Muscle contractions attached to a hard endoskeleton are necessary for human body movements. Tendons connect muscles to bones, which are made of fibers that are built up from the sarcomere, a basic structural component. Within the sarcomere, the thin and the thick filaments have different places of attachment. Myosin head and actin cross-bridges develop and break in response to nervous system motor output, ratcheting the thin and the thick filaments past one another. This sliding motion shortens individual muscle fibers because filaments are attached..
Additionally, muscular contraction causes the boy's bones to shift in relation to one another as the fibers themselves are a component of the muscles and are related to bones at either end. Thus, muscle function—such as the bending of either an elbow by contracting the biceps—is made possible by the structural anchoring between muscles and filaments.
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