Answer: Valves in the veins
Explanation: The flow of the blood inside the body takes place through the veins and arteries. The oxygenated blood from the heart is supplied to the different parts of the body.
The blood flows from the capillaries to the venules and from there to the veins. The blood moves in the veins by the rhythmic movement of the smooth muscles in the body.
Most of the blood moves against the gravity so there is a chance that it can backflow so to prevent this there are valves in the veins known as one way valves.
Answer:
the zygote, because it is formed by the sperm and egg cells of both sex
Answer:
option c punctuated equilibrium
Explanation:
Punctuated equilibrium occurs in a process whereby evolutionary changes occurs in some organisms in a rapid burst of time rather the conceived gradual changes that occurs over a long period of time. this burst of time might be in about 500,000 years. It is assumed that the organism has maintained/lives in stasis for a long period without a need for change, but then, once the change takes place (most of the time, due to an environmental factor), the organism quickly adapts to its new environment with this new adaptation.
