Messenger RNA (mRNA) molecules carry the coding sequences for protein synthesis and are called transcripts; ribosomal RNA (rRNA) molecules form the core of a cell's ribosomes (the structures in which protein synthesis takes place); and transfer RNA (tRNA) molecules carry amino acids to the ribosomes during protein
Answer:
Clomid tricks the body because it tells the brain that estrogen levels are low, thereby leading to higher production of this hormone
Explanation:
There are many types of hormones that are regulated by the negative feedback mechanism (where hormone feeds back to decrease its production). Clomid is a drug used to treat female infertility by making the body think that the concentration of estrogen is low, which induces the secretion of Follicle-stimulating (FSH) and luteinizing (LH) hormones by the pituitary gland. The estrogen hormone exerts negative feedback on the Gonadotropin-releasing (GnRH) hormone, which is responsible for the release of FSH and LH. High FSH levels stimulate the growth of follicles in the ovaries, which will be released during ovulation.
Answer:
C. At least five mass-extinction events have occurred during the last 500 million years.
Explanation:
- The history of mass extinct is related to the five mass extinctions that are caused over by the 350 million years n which many species have disappeared in there short geologic time.
- A massive extinction is caused in the Permian Triassic extinction event i.e about 250 mn years ago which on an estimate has killed 90% of the species.
- The Cretaceous–Paleogene extinction event that occurred over 66 million years ago is known to have wiped out the dinosaurs and many other species.
Plants make their food in their leaves. And need sun for this process, so smaller and fewer leaves means less sun for photosynthesis, and it also means less food to nourish the plant.
