<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>
<span>Lay the frog on its back, spread out its limbs, and pin them to the tray. Use forceps to lift the skin between the hind legs and make a small incision with a scalpel. Continue the cut up the center of the frog's body with scissors, being careful to cut through the skin only. Use forceps to hold the skin away from the muscle while you cut, if necessary. Make horizontal incisions just above the legs and just below the arms, then fold the resulting flaps back and pin them. (You may need to use a scalpel to help separate the skin from the muscle underneath as you fold it back.)Repeat the incisions as before, this time cutting through the muscle layer to a point just below the arms. Lift the muscle with the forceps to prevent cutting the organs underneath.When you reach the area just below the arms, turn your scissors and make horizontal cuts through the hard sternum. Repeat the horizontal cuts just above the arms, and then remove the bony strips entirely. Pin the remaining muscle flaps back, just as with the skin.<span>Look into the body cavity. The yellow finger-like projections on the sides are the fat bodies. It may be necessary to remove some of these in order to see the organs clearly. Likewise, a female specimen may have well-developed eggs filling the body cavity and obscuring the organs. Remove them as necessary.</span></span>
Answer:
B
Explanation:
Because it is your circulation
C.) the cooler the wire, the less the resistance
