Answer:
b.the influence of humans on a natural system can have unpredictable negative impacts
Explanation:
The situation described best illustrated the fact that the disturbance of natural ecosystem by humans can have unpredictable negative impacts.
<em>Option c is incorrect because human alteration of the ecosystem needs to be continuously studied to avoid ecological disasters.</em>
<em>Option d is incorrect because alteration of the ecosystem does not always end up in the pollution of the ecosystem and loss of finite resources.</em>
<u>While human alteration of the natural ecosystem often have long term negative impacts, many of these impacts can not be predicted until they happen. This makes option b to be more complete than option a.</u>
The correct option is b.
Answer:
Cell division is the process by which a parent cell divides into two or more daughter cells.
Explanation:
Explain in your own words. I got this from my Notes from Science.
Answer: the process of building compounds from more elementary substances by means of one or more chemical reactions
Explanation:
Blood cells use a protein called hemoglobin to capture and carry oxygen.
Answer:
D. Serial dilution followed by a colony forming units calculation.
Explanation:
The best way to count bacterial cells such as Salmonella accurately is through serial dilution and calculation of colony forming units.
Serial dilution is made using a petri dish containing appropriate culture medium for Salmonella growth. In this petri dish, with the help of an inoculation loop, the suspension containing the Salmonella will be scratched in the middle of the petri dish. Then, the inoculation loop will be passed over the salmonella streaks and will be dragged to the other side of the plate, where the loop will be scratched halfway through this space. The inoculation loop should again pass over the new salmonella streaks and be dragged through the rest of the petri dish. Then one must wait for the bacterial colonies to grow inside the plate.
Once these colonies are grown, those that appear in isolation will be counted through a specific calculation for the count of salmonella colonies.