"Marine biology" is the study of ocean life, including "fish." So, to solve this analogy you need to determine which of these is studied under "microbiology." Well, the roots micro- meaning small and -bio- meaning life should provide sufficient clues. "Microbiology" is the study of microscopic life, like "bacteria."

"Crest" and "trough" are specific terms used to describe, respectively, the high and low point of waves. So, to solve this analogy you need to determine what a "gibbous" is used to describe and what it's opposite counterpart might be. Well, a "gibbous" is a term used to describe the moon when the illuminated part is greater than a semicircle, but not a full moon. So, the correct answer is "crescent," which is a term used to describe the moon when the illuminated part is less than a semicircle, but not a new moon. Additionally, an "estuary" is the mouth of a river, where the river meets the ocean.

"Cardiac" means of or related to the "heart." So, to solve his analogy you need to determine which of these words means of or related to "mountains." The correct answer is "alpine," which is drawn from the Alps range of mountains in Western Europe.

"Penitent" means feeling regretful and contrite and seeking "forgiveness" for something. So, if someone who is "penitent" is seeking "forgiveness," what is someone who is "hawkish" seeking? Well, "hawkish" means bellicose, desiring conflict or "war."

"Genetics" is the study of "heredity," the study of how traits are passed down from one generation to the next. So, to solve this analogy you need to determine what "linguistics" is the study of. The correct answer is "language."

"Testosterone" is a hormone that is primarily found in "men." So, to solve this analogy you need to determine which of these is a hormone primarily found in "women." The correct answer is "estrogen." Additionally, "adrenaline" is a hormone that is released under stress and promotes accelerated blood-flow, as well as aggression; "melanin" is a pigment found in skin that is responsible for tanning or darkening of skin; "dopamine" is a chemical present in the brain that is related to the sensation of pleasure. 

"Gastronomy" is the art or science of "cooking" and eating. So, to solve this analogy you need to determine what "osteology" is the study of. Well, "osteology" is the study of the skeleton or "bones." 

The term "gait" refers to the style or manner of someone's "walk," how someone "walks." So, to solve this analogy you have to determine which of these is related to "locution." Well, "locution" means the manner or style in which someone "talks."

"Insulin" is something that is used to treat "diabetes." So, to solve this analogy you need to determine what it is that "penicillin" is used to treat. The correct answer is that "penicillin" treats bacterial "infection." Additionally, "paralysis" is the inability to move or feel sensation; "psychopathy" is a mental illness defined by a lack of empathy and a desire to defeat others in all areas of life.

The term "dorsal" means of or relating to the "back" of an animal or organ. So, to solve this analogy you need to determine which of these words is related to "austral." The correct answer, as you may have guessed from "Australia," is that "austral" means of or relating to the "south."