Answer:
Iodine in the food items included in the diet
Explanation:
The thyroid hormones (T3 and T4) are the lipid-soluble hormones and are formed when iodine is attached to the amino acid tyrosine. The triiodothyronine (T3) has three atoms of iodine while tetraiodothyronine (T4) has four atoms of iodine attached to the benzene rings of tyrosine.
Hence, the synthesis of T3 and T4 hormones by thyroid gland depends on the availability of iodine atoms which in turn mostly comes from the diet.
Active transport of iodide ions occurs from the blood into the cytoplasm of the follicular cells of the thyroid gland. In fact, most of the iodide ions are concentrated in the follicular cells of the thyroid gland in the body. Diet serves as a source of iodine and the diet deficient in iodine leads to malfunctioning of the thyroid gland.
The nervous system code for the difference in intensity between a gentle tap with a hammer and a hard blow with the hammer, is that the rate of neural firing and the number of neurons firing. Reflex hammer is a medical instrument used by practitioners to test deep tendon reflexes. Reflex tests are performed as part of a neurological exam, either a mini-exam done to quickly confirm integrity of the spinal cord or a more complete exam performed to diagnose the presence and location of spinal cord injury or neuromuscular disease.
The diagram for evolution of plants in the 4 stages is attached below.
<u>Explanation:</u>
The plants evolution has 4 main periods:
<u>A. 1st Period of Plant Evolution
</u>
About 420 million years ago, plants evolved from algae. Formation of cuticle was the first terrestrial adaption.
<u>B. 2nd Period of Plant Evolution
</u>
Abut 400 million years ago, the diversification of vascular plants came into being. The early vascular plants lacked seeds.
<u>C. 3rd Period of Plant Evolution
</u>
This was around 360 million years ago, that the seed evolved. The plants had seeds, but they did not have any covering, so they were called naked seeds. These plants were gymnosperms.
<u>
D. 4th Period of Plant Evolution
</u>
This was the evolution of flowering plants, happened around 130 million years ago (during early Cretaceous period). The flowering plants were called angiosperms.
In the agricultural practices cover plants are grown for the enrichment and the protection of the soil. They are not harvested to be sold as cash crops.
<h3>What are the cover crops used for?</h3>
Cover crops are grown in the agricultural land parts to maintain the soil fertility and quality so that the land will be safe from the invasion and attacks of pests and weeds.
They are generally grown after the reaping of cash crops and help in soil binding by preventing erosion from the water runoffs.
These plants help in fixing the nitrogen content of the soil and help the soil to remain fertile and nutrient-rich. They increase the organic and the mineral compounds to the soil profile and enriches the soil quality.
Therefore, option c. they are sold as cash crops is incorrect.
Learn more about cover crops here:
brainly.com/question/6704704