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: Because epinephrine activates the fight or flight response, related to the sympathethic response in the body.
Explanation:
The function of the Autonomic Nervous System is the regulation of the system cardiovascular, digestion, respiration, body temperature, metabolism, exocrine glands, and therefore keep the internal environment constant (homeostasis). While sympathetic activity increases in stress, the activity parasympathetic predominates during rest and satiety. The adrenal medulla originates from the neural crest and is composed of neuroendocrine specialized cells and are responsible for the production of catecholamines.
Catecholamines are dopamine, adrenaline, and noradrenaline (epinephrine and norepinephrine). Epinephrine prepares muscles, lungs, and heart for more intense activity, in situations of stress. It promotes the increase in the force of contraction in the muscles and increases in the heart rate. It also leads to increased blood pressure and bronchodilation, for greater availability of O2.
Answer:
B) 1/2 X 1/2 = 1/4
Explanation:
It happens when both the parents are heterozygous for the trait. The cross related to this result is shown as under:
Father Mother
Bb x Bb
/ \ / \
Gametes: B b B b
| | | |
Probability: 1/2 1/2 1/2 1/2
The probability of formation of 'b' gamete from father is 1/2 because there are only two gametes 'B' and 'b' and out of these two one will be assorted as 'B' and another one as 'b' and from mother also the probability of formation of 'b' gamete is 1/2.
Now the assortment of gametes with each other is an independent event i.e. any gamete from father can fuse with any gamete of mother so the overall probability of formation of 'bb' genotype will be 1/2 x 1/2 = 1/4.
Answer:
AAT-TTG-CTC-GAC-GAT
Explanation:
The complimentary strand contains the bases that the parent original strand binds to.
Answer:
The increase in stomatal density translates to an increase in gs and 30% greater photosynthetic rate under high-light conditions
Explanation:
