Which of the following taxonomical ranks contains organisms that are least similar to one another?

Four statements are given below regarding species. Which two statements are correct?
$(1)$ Maximum similarity in maximum number of characters.
$(2)$ First letter in capital letter.
$(3)$ Latin word written after the scientific name.
$(4)$ Repetition of the species name is not possible.

Which one of the following animals is correctly matched with its particular taxonomic category?

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?

Identify the correct pair (Genus - Family).

What is the group of individuals that share maximum characteristics, have maximum similarity, and have the ability to interbreed to produce fertile offspring called?