Answer:
Option-C
Explanation:
Scientists found a fossil of a fish with four limbs or legs. The fossil was estimated to be around 375 million years old.
The fossil showed the fins and scales of a fish but they also possess the bones of proto-wrist, shoulders and the elbow.
The presence of these bones can be a clue that the fish evolved the limbs to walk on the land and will later evolve into animals belonging to amphibians, reptiles and mammals. Therefore, the Tiktaalik is considered the missing link of how life evolved from water to land.
Thus, Option-C is correct.
Answer:
An anabolic steroid
Explanation:
Anabolic steroids ca also e referred to as anabolic-androgenic steroids. They are synthetic or man-made steroids that mimic natural androgens like testosterone in their structure and functions. It is majorly used for muscle mass building.
When anabolic steroids are misused or abused, it can have an effect on an individual's mental health and presenting symptoms like depression, mood swings, mania, aggression etc.
Some athletes and bodybuilders take anabolic steroids to promote building of their muscle mass rapidly.
DNA is a dynamic and adaptable molecule. As such, the nucleotide sequences found within it are subject to change as the result of a phenomenon called mutation. Depending on how a particular mutation modifies an organism's genetic makeup, it can prove harmless, helpful, or even hurtful
