<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>
The lymphatic system drains into lymphatic trunks (right and left lymphatic duct) which drains into vessels of the neck (right subclavian vein)
Hello,
I believe you're asking which option is true. If so, A) do not require a medium. Unlike mechanical waves, electromagnetic (or light) waves do not require a medium. It has been proven that light travels in a straight line. Light waves are, in fact, electromagnetic radiation, and they can travel in a vacuum.
Faith xoxo
Answer:
Osmosis is the diffusion of water molecules across a permeable membrane from an area of higher concentration of water molecules to an area of lower concentration of water molecules concentration until equilibrium is reached
