<span>Vascular plants are able to grow higher than other plants due to the rigidity of xylem cells, which support the plant.</span>
Answer:
Hypothalamus and anterior pituitary gland.
Explanation:
Lower levels of T3 and T4 in the blood or lower metabolic rate serve as signal and stimulate the release of thyrotropin-releasing hormone (TRH) from the hypothalamus. The TRH stimulates the anterior pituitary gland to release thyroid-stimulating hormone (TSH) which in turn makes the thyroid gland to release the thyroid hormones.
The elevated levels of thyroid hormones inhibit the release of TRH from the hypothalamus and that of TSH from the anterior pituitary gland.
Hence, the cells of hypothalamus and anterior pituitary gland would be inhibited by the binding of thyroid hormone to regulate the release of these hormones by a negative feedback mechanism.
Answer:
Killer T cells release enzymes that help destroy invading foreign matter (antigens), Helper T cells, on the other hand, stimulate another type of lymphocyte known as B cells. B cells produce antibody, which is a protein made in response to a specific antigen.
the one that is considered a chemcial mutagen is : Tobacco Chemical mutagen refer to the substance that affected the DNA of those who consume the substancce or their offspring. Studies showed that consuming tobacco has proven to created DNA deformations for the fetus if it consumed by pregnant women.