What is a possible benefit of studying plants in the rainforest? 1) The Plants may hold medicines to treat human diseases - 2) The plants may produce need it carbon dioxide - 3) The plants may be cut down and sold in floral shops - 4) The Plants may make Toxins for human consumption

The plants may produce needed carbon dioxide.

Explanation:

This is the only benefit as medicine needs to be found, they won't be cut down, and they do take in toxins but it does not affect the study

The animals used in an experiment that involves USDA pain category B, C, and D activities performed on the same animal should be categorized to USDA category D.

The USDA pain categories are used to categorize the level of pain an animal used in testing and research will be exposed to. The categories are as follows:

USDA B: the animal will not feel pain of any kindUSDA C: the animal will feel the occasional slight painUSDA D: Painful procedures that will be mitigated by pharmaceuticals.USDA E: Painful procedures that will not be mitigated.

Category B states the animal will not feel pain. Animals in this category are often used for breeding, which is a natural process that does not cause animal distress or pain.

Animals in category C may feel the occasional slight pain which is allowed to subside naturally without the use of pharmaceuticals. This may include procedures such as

Drawing blood samplesInjections

Animals in category D are exposed to painful or stressful procedures and will receive anesthetics and other chemical agents to mitigate or completely relieve the pain, Whereas E category animals do not receive said assistance.

These categories follow a strict rule. Animals must be categorized according to the most painful procedure it will undergo, so because the experiment will use USDA B, C, and D procedures, the animals must be placed into USDA category D.

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