What characteristics make these genres similar in terms of structure

Assuming you are talking about movie or book genres, the characteristics that can make them similar are:

similar plots similar characters similar settings

A genre is made up of several things such as the plot, the story, the characters and the settings.

Sometimes these things that make up a genre will be so similar that the genres will be similar in structure. Traditionally, there are genres that go well together such as:

Romance and Comedy - Romcoms are they are called, developed because it was possible to merge the romance and comedy genres because they had similar settings, characters and plots. Action and Comedy - in the past decades, it has also become possible to merge action and comedy as well because characters were made serious yet down to Earth and funny.

In conclusion, genres are made similar in structure when they have similar components.

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The correct answer to this open question is the following.

Although the question is vague and does not include options, context, or any further reference, we can help to comment on the following.

If you are talking about the different movie genres, then we would say this.

The characteristics that make these genres similar in terms of structure are the structure of the movie: the premise, the plot of the movie/the action, the location, and the characters of the story. These are what defines the type of movie genre that could be drama, comedy, action, thriller, terror, western, romance, children, adventure, and science-fiction basically. Most of these genres can have subcategories, according to the specific topic of the story.

Associative properties of multiplication