In which of the following pairs of categories is it more difficult to determine the relationship to other taxa at the same level,thus making the problem of classification more complex?

As we go from Kingdom to Species, the number of common characteristics $ \dots $ and the number of species $ \dots $.

Which of the following represents the correct scientific name of the mango?

Which of the following is $NOT$ true for a species?

Which of the following taxonomic categories is being described by the given statements $(i-iii)$?
$(i)$ It is the basic unit of classification.
$(ii)$ It is defined as the group of individuals which resemble in their morphological and reproductive characters and interbreed among themselves and produce fertile offspring.
$(iii)$ Human beings belong to the species $sapiens$ which is grouped in the genus $Homo$.

Which scientific term is used for the study of groups of organisms like mammals,reptiles,and plants?