Answer: c
Explanation: Plants and animals need nitrogen to make proteins but they cannot take it in from the air. Because nitrogen is unreactive as a gas, it has to be transformed into a new molecule. When bacteria in the soil takes nitrogen from the air, it becomes nitrates. Finally, it can move through the food chain in this form.
The study pushes back the clock on the origin of Earth's water by hundreds of millions of years, to around 4.6 billion years ago, when all the worlds of the inner solar system were still forming. Scientists had suspected that our planet formed dry, with high-energy impacts creating a molten surface on the infant Earth.
Answer: 4.6 billion years.
The answer A. DNA in the nucleus controls all cell activity.
It would be A. Iron & Nickel.
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Answer:
Graves´ disease is an autoinmmune disease that is caused when the immune system attacks the cells of the thyroid gland, which leads to an overproduction of the hormones secreted by the thyroid gland. This constant attack and destruction on the part of the immune cells causes the thyroid to increase in size, a condition that is commonly known as hyperthyroidism.
Hyperthyroidism can become a really serious issue because the excessive production of the hormones of the thyroid gland will increase the metabolic activity of all parts of the body and can, if left untreated, cause such serious conditions as blood clotting problems, type 1 diabetes, among others.