Answer:
except natural killer cells.
Explanation:
The Helper T cells produce cytotoxic T cells and help B cells, but not natural killer cells
Answer:
<em>The correct option is D) How is the number of frogs in Massachusetts affected by pollution</em>
Explanation:
A scientific question can be described as a question which can be answered through the scientific method of research. Based on the scientific question, a hypothesis can be formulated. For example, for the option D, the hypothesis can be 'if the pollution increases, then the number of frogs decreases.' A hypothesis is a tentative statement which can be tested through experiments. Based on these experiments, results are formulated and conclusions are drawn. The question mentioned in option D can be answered through this method hence, it is the correct option.
Your teacher likes to copy. Found this at https://examples.yourdictionary.com/examples-of-keystone-species.html
Grizzly bears: As predators, bears keep down the numbers of several species, like moose and elk. They also carry and deposit seeds throughout the ecosystem. Bears that eat salmon will leave their dropping and the partially eaten remains that provide nutrients such as sulfur, nitrogen and carbon to the soil.
Variation of trainers HELP species.
Answer: The amount of water in the blood would increase.
Explanation: