<span>It may be difficult for ecologists to determine the size of a bird population if that population migrates to different locations throughout the year. During migration, some birds may split off from the group and not return, others may die, and still others may join. Therefore, the bird population will be in constant flux. It is hard to know, when the birds return to their prior location, if the population consists of the same group of birds (in addition to deaths and births) or whether it has grown or shrank through other means. However, to estimate the size, an ecologist can track a migratory flock through several years, counting each year to get a general sense of the population size. Additionally, given one measurement, an ecologist could consider the average lifespan and birth rates of the population to extrapolate the size of the population in subsequent years.</span>
Answer:
increasing pressure inside the lymph capillary
Explanation:
Lymph is a fluid like the blood which carry the White blood cells which can fight against the infection. The lymph flows in separate vessels called lymphatic vessels.
The lymphatic vessel is very thin-walled smooth muscle containing tube-like structure which allows the transport of lymph.
The lymph vessel like blood vessel contains the valves called mini valves which prevent the backward flow of the lymph.
When the pressure in the tiny lymph capillaries which supplies lymph to the organs increases, the mini valves closes to prevent backflow of lymph and is the mechanism of lymph flow.
Thus, the selected option is the correct answer.
When the fertilized egg implants somewhere outside the uterus is called ectopic pregnancy
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Because most waste produced in the cell is toxic when it accumulates.
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