A. Hormones act as signal molecules between all body systems
Peripheral Chemoreceptors (Carotid + Aortic Bodies) and Central Chemoreceptors in the Medulla Oblongata detect high Carbon Dioxide levels in the blood during exercise. The respiratory centre in the Medulla Oblongata + PONS stimulate the intercostal muscles and the diphragm to contract in order to increase the rate and depth of breathing as to decrease levels of Carbon dioxide in the blood.
The thyroid gland secretes thyroxine which speeds up metabolism (the rate at which cells use glucose)
The chance of a coin landing heads or tails is 50% for each individual time. It doesn't matter what the previous throws resulted in. If you flip a coin ten times you can get ten heads, but the probability is still 50% for each toss. The same holds true with gametes. The probability is 50% at the production of each individual cell.
I think the correct answer from the choices listed above is option B. Within each cell of your body there are chromosomes <span>which give the instructions for cell processes. These instructions include the differentiation of your blood cells. Hope this answers the question. Have a nice day.</span>
The answer is The ions are protected inside the lipid bilayer so that it is not pushed back to a more polar environment.
The lipid bilayer is mainly composed of lipids (phospholipids and cholesterol), and is also composed of proteins such as transporters.
The ions (which are polar) can not cross directly through the lipids because they will repel them due to their apolarity. On the other hand they can easily pass through protein channels that will protect them during their passage (the proteins are more polar than lipids).
Answer:
d. transcription factors
Explanation:
Transcription factors are the proteins present in cells that are involved in the regulation of gene expression. The transcription factors may increase or decrease the expression of a gene. Therefore, a transcription factor may serve as an activator or repressor for a gene. These proteins bind to a regulatory sequence present near or within a gene, interact with RNA polymerase or other transcription factors and thereby, affect the transcription initiation.
Since binding of dioxin to certain proteins alter the pattern of gene expression in the cells, these proteins are the transcription factors. For instance, dioxin may bind to a transcription factor and up-regulate the expression of genes which in turn regulate the cell division.
