D) there is evidence of dramatic negative results every time the magnetic poles reverse
Explanation:
Paleomagnetism is the Science that studies the magnetic field of rocks to assess changes in the Earth's magnetic field in remote times and to study the movement of continents in geological time. The studies carried out indicate that the Earth has had a significant magnetic field, at least, 2.7 billion years ago.
The magnetic field of rocks has beneficial and harmful effects on our planet. Regarding paleomagnetism at spreading ridges, there is evidence of dramatic negative results every time the magnetic poles are inverted.
The true statement is that it evidences the dramatic negative results every time when the poles of the magnet get reversed.
Option D
<u>EXPLANATION: </u>
There are two poles: North and South Pole in Earth's magnetic field. When lava erupts at mid-ocean ridge, it cools and becomes a hard rock. During this process of cooling, the rock becomes magnetised.
Scientists have discovered that the magnetic field of Earth has been reversed in direction hundreds of times, which means that the polarity of North pole and South pole reverses.
Due to this reversal, a pattern of magnetic stripes is created in symmetry on both sides of the mid-ocean ridges.
A diet deficient in calcium can cause osteopenia. The deficiency of calcium may Cause a low bone density which is a condition caused in osteoporosis. Hence the correct answer is B osteopenia.
Photosynthesis requires sunlight, carbon dioxide, and water as starting reactants (Figure 5.5). After the process is complete, photosynthesis releases oxygen and produces carbohydrate molecules, most commonly glucose.
