The controlled experiments are performed by the scientists, when they want to study the changes in the sample on changing a single variable. So, the correct answer is option (b).
In case, all variables are kept same, no changes would be observed in the experiment sample. A controlled experiment can be performed on living thing as well as non living. But, controlled experiment cannot be performed on the things which are influenced by a lot of variables, as they cannot create realistic results. So, the option (a), (c), and (d) are incorrect.
Answer:
The goal of systematics is to organize living things into groups that have biological meaning. the science of naming and grouping organisms.
Explanation:
The term for the type of key that biologists used in separating<span> groups of organisms that are based on couplets is called taxonomic key. This key is very useful in the identification and classification of a </span>specific organism and it usually has an analytical characteristic.<span> </span>
