Answer:
Option A
Explanation:
Thyroid is primarily caused by lack of iodine but there are other reasons as well that lead to increased size of the thyroid gland. Some of these reason is
a) over- or underproduction of thyroid hormones
b) Nodules in the glans
Some times, due to overstimulation immune system itself attack the thyroid gland thereby producing excess thyroxine and hence causing the thyroid to swell
Thus, Option A is correct
Answer:
sarcoplasmic reticulum deteriorates and ATP production is stopped
Explanation:
Rigor mortis is the third stage of death characterized by stiffening of joints and muscles in body. The stiffening occurs because muscles are not able to return to the relaxed state. There are two reasons for rigor mortis, depletion of ATP and increase in calcium concentration in cytosol. Due to these factors the actin-myosin crossbridge is not able to break and the muscles remain in contracted state.
Sarcoplasmic reticulum deteriorates and calcium is released into the cytosol. Sarcolemma ( covering of muscle fiber ) also breaks down releasing extra calcium into the cytosol. Calcium is responsible for formation of actin-myosin cross bridge and when its concentration increases the bridge is formed continuously leading to stiffening of muscles and joints.
Answer:
Due to the large number of fossils being discovered at that time Darwin proposed that species change over long periods of time.
Explanation:
The theory of Darwin was that the species change in accordance to their environment, thus they develop advantageous traits so that they can be more competitive.
