Lasting genetic similarities make the two bears biological sister species, more closely related to one another than to any others. ... But Ursus maritimus has also evolved to match its polar environment, growing a longer snout than brown bears' and larger, paddle-like paws, both of which aid polar bears in hunting seals.
<span>Cocaine is an indirect agonist of dopamine <span>receptors which</span> means he </span>has no specific agonist activity at the dopamine receptor<span> but he enhances his activity. Cocaine</span> acts by binding to the dopamine transporter, blocking the removal of dopamine from the synapse and blocking termination of dopamine signalling. As a result, it increases the extracellular concentration of dopamine and therefore signal to the receiving neurons is amplified.
The right option is; Hormones are the chemical signals, which are sent all through the body to monitor other processes of the body.
Hormones are chemical messengers that are secreted from the endocrine glands, and are released directly into the bloodstream, which transports them to tissues and organs to perform their functions. Different types of hormones act on different body function and processes. Hormones influence the body’s functions, including development and growth, cognitive function and mood, sexual function and reproduction, regulation of body temperature and thirst, and food metabolism.