All medical research is carefully planned, and this includes medical
research with animals. Experts who review a scientist’s proposed
experiment involving animals weigh several considerations before
approving each study.
The most important thing is that the research must be relevant
to human or animal health. Studies need to protect the animals’
welfare. That means that only the fewest number of the most
appropriate species may be used. Under federal law, all animals
must be treated humanely and undergo the least distress possible
Creeping thistle continuously survives through easy germination of seeds. The Creeping thistle seed can be buried in undisturbed soil for over 20 years and still become growable. And also, the roots help in their growth. They absorb nutrients and regenerate to form new plants. Although the roots may be able to penetrate some meters down, most regeneration occurs within or just below the plow layer. Portions of the adjacent roots become thick due to the developing storage tissue which is where new shoots are formed.
Secondary pollutants are more harmful than primary pollutants. False
<h3>Primary and secondary pollutants</h3>
Primary pollutants are pollutants released directly to the environment from their sources.
Secondary pollutants are formed from the reactions of primary pollutants with other substances in the environment.
Both primary and secondary pollutants can equally be harmful to living organisms. What distinguishes their harmful level would be the nature of the substance.
Thus, saying that secondary pollutants are more harmful than primary pollutants is not completely true.
More on pollutants can be found here: brainly.com/question/23857736
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