<span>Penile shaft
</span>During erection, blood<span> flows into the spaces, causing distention and elevation of the penis. The amount of blood entering the penis can be increased by physical or psychological stimulation. As blood enters, there is a temporary reduction in the rate and volume of blood leaving the penis. The arteries carrying blood to the penis dilate; this, in turn, causes tissue expansion. The veins leading from the penis have funnel-shaped valves that reduce the outflow of blood. As the erectile tissue begins to enlarge, the additional pressure causes the veins to be squeezed against the surrounding fibrous tissue, and this further diminishes the outflow of blood. Essentially, blood becomes temporarily trapped in the organ.</span>
Eukaryotes are organisms whose cells have a nucleus enclosed within a nuclear envelope.
Answer:
C
Explanation:
all of them have negative effects on the enviroment as a whole but C gives no reason why it would be a consequence
The study of one type of evidence of evolution is called embryology, the study of embryos. An embryo is an unborn (or unhatched) animal or human young in its earliest phases. Embryos of many different kinds of animals: mammals, birds, reptiles, fish, etc. look very similar and it is often difficult to tell them apart.
