It basically means a superficial wound :)
The correct answer is option d.
A vaccine refers to a biological preparation, which offers active acquired immunity to a specific disorder. A vaccine usually comprises an agent, which signifies a disease-causing microbe and is usually made from killed forms or attenuated microbe, one of its surface proteins, or from its toxins.
The agent instigates the immune system of the body to determine the agent as a danger, destruct it, and to further destroy and identify any of the microbes related with that agent, which it may come across in the coming future.
Answer:
That's not all: chickens are close relations of dinosaurs, and genetic patterns in the brains of birds that learn new calls show remarkable similarities to humans. These findings stem from a project that sequenced genes from 48 bird species and then used several months of supercomputing time to analyze relationships.
Skeletal muscles
Structure; they are long cylindrical fiber, striated, many peripherally located nuclei.
Functions; Voluntary movement, produces heat, protects organs.
Examples; the biceps, slow twitch fibers, fast glycolytic fibers.
Cardiac muscles
Structure; they are short, branched, striated, single central nucleus
Functions; Contracts to pump blood, they are found in the heart
Examples; Heart muscles
Smooth muscles
Structure; They are short, spindle shaped, no evident of striation, single nucleus in each fiber
Function; Involuntary movement, moves food, involuntary control of respiration, moves secretions, regulates the flow of blood in arteries by contraction.
Example; Muscles found in the walls of hollow organs like the intestines, stomach and the blood vessels.
