<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:
<u><em>C. DNA from the S bacteria is necessary for bacterial transformation to occur.</em></u>
Explanation:
These series of experiments determined that DNA is the genetic material which gives rise to a particular type of cell. As we can see, the S bacteria with degraded proteins were able to grow when the proteins and RNA were degraded. But they were not able to grow when their DNA was degraded. This experiment proved that proteins or RNA are not the genetic material, rather DNA is the material related to inheritance.
Answer:
Cold air is denser than warm air, it will sink below warmer air, pushing warm air upward.
Explanation:
Answer:
Renewable energy resource as an obstacles for the growth of migratory salmon populations: It is now believed that the reduce access to spawning grounds and nursery areas, leading to a decrease in migratory fish populations is due to the dam structures of large storage-type schemes, which can create great obstacles for the movement of migratory fish species.
Explanation:
- Storage-type schemes ( big dams) can significantly change the downstream flow regime,and may also alter water temperature and quality, and even make it inhabitable for fish to live.
- As the storage of water can be linked with high evaporative losses, which in turn results in high life cycle water footprints compared to other sources of electricity.
<u>Run-of-river (ROR) schemes are HEP schemes: </u>
They operate without water storage, using the flow within a river channel.They are ecologically friendly and do not disturb the natural mechanism for the migrating salmons.
Working Principle:
They are normally used to regulate water levels, which allows a proportion or part of flow to be diverted down a secondary channel to a turbine before it is returned to the main channel further downstream.
There are some modern turbine types used in ROR HEP(hydroelectric power) schemes, which are also designed to allow fish to pass through the system unharmed if the fish do pass through the intake screens.
Answer:
2-3 hours
Explanation:
Insect activity will begin immediately if a body is left in the open. That is why insect activity can help investigations with determining certain things such as time of death, where the person died and the like. 3. A light meal will digest in about 1-2 hours.
