<span>The correct answer is A, B and D. Biogeochemical cycles are central to the ecology of earth system. They make the essentail elements accessible and available for the organisms, and maintain their levels, so that the ecology is ot disrupted. The elements move through abiotic and biotic factors, in these cycles, and a state of equilibrium is maintained n the ecosystem. The carbon dioxide levels are responsible fr the temperature of the earth. If Carbon cycles would not have existed, then there would have been a disruption in maintaining the global temperature. Biogeochemical cycles basically continuously recycles the essential materials, for sustaining the life-forms.</span>
Answer:
They act to regulate the expression of specific genes (androgen-responsive)
Explanation:
Testosterone is a reproductive hormone in male humans. Testosterone as well as its closely related hormones e.g dihydrotestosterone, all belong to a class of hormones called "Androgens".
Androgens operate by entering into a cell and binds with specific androgen-receptor proteins (AR proteins). This contact activates the AR proteins, forming an androgen-receptor complex.
This complex then translocates into the nucleus of specific cells to bind to the DNA. Once it binds, it either inhibits or promotes the expression of specific genes (androgen-responsive). Hence, AR proteins are transcription factors because they play a significant role in regulating transcription of specific genes i.e. turning 'on' or 'off' of specific genes.
This process helps to direct the development of male sexual characteristics.
Answer:
Since boron only has two electron shells, it is about as capable of gaining electrons as it is of losing electrons, so it behaves as a metalloid. The other elements in this group have more electron shells, so it is much easier for them to lose their valence electrons and they behave like metals.
Answer:
A
Explanation:
These are small consecutive repetitive sections of the DNA – mostly between 5 – 50 times repetitions. They are not part of coding regions (genes) and therefore are prone to non-lethal mutations of DNA. They are therefore very variable between individuals and can be used for DNA forensic identification.
