Answer:
Option A, Hormones are controlled by a feedback loop; information about a system is sent back to the controller of the system to improve its function.
Explanation:
Negative feedback loop controls the hormone production and release. This is done by eliciting the release of substances till a certain level after which the stop signal is activated thereby preventing further release. By this method, concentration of hormones in blood is maintained within the narrow range.
For example – Thyroid hormones is released when the anterior pituitary signals the thyroid. This continues till the hormones in the blood reach the threshold level. Once the threshold level is reached, hypothalamus receives a feedback and then signals anterior pituitary to inhibit further signaling to the thyroid
Hence, option A is correct
Answer:
B
Explanation:
When humans dig-up fossil fuels and burn them to power the modern world, <u>carbon flows between the Geosphere/lithosphere and the atmosphere.</u>
Both the geosphere and the atmosphere represent important reservoirs of carbon. The digging-up of fossil fuels, otherwise known as exploration, is carried out in the geosphere or the lithosphere part of the earth. For example, crude oil is obtained deep from the ground. When the fuels are burned, they release carbon in the form of carbon dioxide into the atmosphere.
<em>Hence, it can be concluded that carbon flows from the geosphere/lithosphere part of the earth to the atmospheric portion of the earth when fossil fuels are burned.</em>
The correct option is B.