"Evil Under the Sun": Book vs. Movie Quiz

Answer: "Chez Daphne", the Mediterranean

The novel opens with a short history of the house on Smugglers Island. It was built by Captain Roger Angmering and later converted into a hotel.
The movie is set in the fictional kingdom of Tyrania on the Mediterranean, and Daphne Castle received the hotel, the king's former summer palace, from the king "for services rendered".
QUIZMAKER'S NOTE: I'm not going to rehash the entire plot here or explain any characters beyond the requirements of the respective questions, as I'm assuming that you are familiar with either book or movie, or both. If you don't know anything about either, I suggest you stop reading the answer screen right now to avoid major spoilers. This crime story works best if you have no initial clue of who did what, and why :)

Answer: he really is on a vacation

Poirot is really only enjoying a vacation in the book. In the movie, he is sent to Daphne's hotel on purpose to investigate the story behind a fake diamond. That diamond was given to Broadway star Arlena Stuart by Horace Blatt and returned to him upon her marriage. When Mr. Blatt wanted to have the diamond insured, it was found to be a fake.
In contrast to the movie, the Horace Blatt in the book does not have any diamonds - fake or not - and is not a friend of Poirot's.

Answer: Rosamund Darnley

Daphne Castle was played by an exceptionally charming, and very red-haired, Maggie Smith. Her function in the plot is similar to that of Rosamund Darnley in the book: she is an old friend of Kenneth Marshall and tries to support his alibi.

Answer: All of these options are correct

In the novel, Carrie and Odell Gardener are nice and friendly American tourists who spend their holidays in England. Mrs. Gardener is a chatterbox while Odell is more of the quiet kind, although he does display a fine, dry sense of humor when you manage to catch him without his wife, as one of the characters notes.

Other than that, the Gardeners are mainly supporting characters. In the movie, Mrs. Gardener is called Myra, and she is the one to accompany Patrick Redfern on his boating tour. She is also much more caustic and vulgar than in the book, and tends to boss her husband around.

The Gardeners are theatrical producers from New York and lost a lot of money when Arlena Marshall abandoned their show, which had been advertised with her as the main attraction.

Answer: He is a chain pipe smoker

While Patrick is almost never seen without his pipe (and that was indeed added in the movie), it is a key plot point that he never lights it. So it is not true that he is a chain smoker, which automatically makes this answer the correct one. Sorry for the red herring, but this is a Poirot quiz, after all... Patrick's smoking habits are not discussed at all in the book.
As for the other options:
Patrick's profession is never stated in the book; it is said, though, that Christine used to be a teacher, which underlines the image of her as a brainy, unfit woman. (She was indeed a teacher, but her subject was sports.)
In the flashback, we see Patrick (a.k.a. Felix Ruber) lighting his pipe on a train in a non-smoking carriage. That scene was added; in the book, it is stated that he paced up and down the street in front of the café where he was meeting his wife.
The "Joe Green" joke and everything it entails cannot be found in the book, where Patrick's other name is Edward Corrigan.
In case you don't remember: Patrick jokes that Giuseppe Verdi would have been called "Joe Green" if he had been an Englishman. That helps Poirot find out that Felix Ruber and Patrick Redfern are the same person, because "filix ruber" is Latin for "red fern".

Answer: Rex Brewster

Rex Brewster, deeply despised by Linda, is a rather pompous writer who wants Arlena's permission to publish her biography, which she flatly refuses. His name, "Brewster", is the only thing he has in common with the book, where there is a character called Emily Brewster (whose main function was to discover Arlena's "dead body" together with Patrick, a role taken over by Mrs. Gardener in the movie).
The other options are all characters from the book that were omitted from the movie or incorporated into other characters.

Answer: True

That is true: Arlena caused a financial loss to the Gardeners; she denies Rex Brewster her permission to publish his book, which will presumably lose him the cash advance on it; she and Daphne are old rivals in more than one sense; she treats her stepdaughter Linda with absolute derision and contempt; and her obvious affair with Patrick Redfern affects both her own husband and Patrick's wife, Christine. Not to mention Horace Blatt's diamond.
In the book, the Gardeners have nothing to do with Arlena, but there is the vicar Stephen Lane, who considers her pure evil.

Answer: drug smuggling

During the investigation of the murder of Arlena Marshall, the police discovers heroin on the beach where she was killed. While at first they assume that Arlena might have inadvertently come upon the smugglers, it turns out that this plot point is entirely unrelated to the murder.

Answer: the cannon at noon

It is a rather major plot point in the movie that a cannon is fired every day at noon. That cannon helps Poirot determine the chronology of that morning and to establish who was where when it went off.
He manages to do that without any acoustic help in the book.
The bottle and the bath feature in both, book and movie, while the pair of scissors found on the beach where Arlena was killed was omitted from the movie. In the book, Poirot remarks that this pair of scissors was the only thing that the murdering duo forgot.

Answer: True

Poirot gives his speech and explains how everything happened, or must have happened, and produces evidence that identifies Patrick and Christine Redfern as two people involved in the murder of Alice Corrigan: her husband, Edward, and the young athlete who found the body.
In the movie, Patrick and Christine demand proof and Poirot has to admit that he has none. Christine then famously remarks that they only need ten minutes to pin the murder on Poirot instead. The Redferns then pack their things and are about to leave.
However, Patrick is subsequently outwitted by Poirot. His fake name, Felix Ruber (Edward Corrigan in the book), is explained by the "Joe Green" joke; his handwriting is identified as that of said Felix Ruber; and the real diamond is discovered in the pipe that he always carries but never actually smokes.