Answer:
B.
Explanation:
due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.
The effect of such toxic chemicals to the body is that they stimulate uncontrolled cell division. Uncontrolled cell division or cells proliferation may lead to cancer. The unchecked cell growth results to mutations in genes that can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as cell cycle arrest or programmed cell death.
Plants produce oxygen and glucose as a result of photosynthesis
Calcium levels in the body are maintained by hormones. If the blood calcium level rises above a set point, calcitonin is secreted by the thyroid gland and sets into motion responses to lower the blood calcium back to the set point. If the blood calcium level falls below a set point, the parathyroid gland secretes parathyroid hormone that sets into motion responses to raise the blood calcium. These homeostatic responses are examples of:
a. positive feedback
b. effectors
c. sensors
d. negative feedback
Answer:
d. negative feedback
Explanation:
Negative feedback responses are the ones that counteract the change. Any alterations in the internal body conditions such as blood calcium levels are sensed by receptors. The information is sent to the brain which in turn commands the effectors such as endocrine glands to secrete the required hormones to restore the normal conditions. Here, changes in the calcium levels are counteracted by the secretion of calcitonin and parathyroid hormones and the calcium is maintained within a narrow range. This represents negative feedback.
Answer:
MNP stands for the most probable number which is used for finding out the concentration of viable bacteria in a sample. It is commonly used to check the quality of water and its safety. Usually, the presence of fecal coliform bacteria is checked in this test.
Principle of MNP: The sample which is to be tested is diluted serially and then inoculated into a broth medium containing lactose. If coliforms are present in the tube than it will consume lactose and release acid and gas.
Color change represents acid production and gas trapped in the Durham tube represents the gas production by bacteria. Then the number of tubes at each dilution that showed positive results are compared with standards to determine the most probable number of the bacteria.
