<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:
1)The atomic mass number of an element
2)The relative electronegativity of an element
3) The period of an element
Answer:
White blood cells (WBCs) are specialized to respond to antigen and produce antibodies as well as undergo phagocytosis in response to toxic stimuli.
WBCs are part of immune system and there are five different kinds with specialized features.
In order to make a cell model, it is best to use a muscle cell and a nerve cell or neuron: there are pronounced structural differences and those are present throughout animal kingdom.
Lower animals ( such as insects, worms etc. ) have different immune system, however, they do have typical neuron and a muscle cell/skin cell (fibroblast). Such cell models are likely to be easy, distinct and bring you good grades without going through much complication and confusions of various organ systems and animal mod
Explanation:
