Mathematician and meteorologist Edward Lorenz used the metaphor of the 'butterfly effect' to explain how seemingly minor events can have...

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

• Mathematician and meteorologist Edward Lorenz
  • used the metaphor of the 'butterfly effect'
    • to explain how seemingly minor events
      • can have major impacts on future weather.

• According to Lorenz's metaphor,
  • the wind
    • from a butterfly
      • flapping [?] in Brazil
  • might eventually grow into a storm
    • elsewhere across the globe.

Understanding the Meaning

The first sentence introduces us to Edward Lorenz and his famous metaphor:

• He used the 'butterfly effect'
  • to explain how small events can create big impacts on weather.

Now the second sentence gives us the actual metaphor:

• 'According to Lorenz's metaphor, the wind from a butterfly flapping _____ in Brazil...'

Now here's where we need to fill in the blank. The butterfly is flapping something. What would a butterfly flap? Its wings.

Let's look at our choices to see what we're deciding between:

• A: its wings
• B: its wings'
• C: it's wing's
• D: it's wings'

So we're deciding two things:

• "its" vs "it's"
• How to handle "wings" - plain plural, or with apostrophes

What do we need here?

• The wings belong to the butterfly - we need to show possession.
• For the pronoun "it" (referring to the butterfly), the possessive form is "its" (no apostrophe)
  • Just like "his" or "her" - possessive pronouns don't use apostrophes
• "It's" with an apostrophe means "it is" - that would give us "a butterfly flapping it is wings" which makes no sense.

For the second part:

• A butterfly has wings (plural)
• "Wings" here is just the thing being flapped - a simple plural noun
• We don't need any apostrophe on "wings" because the wings aren't possessing anything
  • They're just the body parts that belong to the butterfly

So we need: its wings (possessive pronoun + plural noun)

The answer is A.

Now let's read the rest to see the complete picture:

• The sentence continues: 'might eventually grow into a storm elsewhere across the globe.'
• So the complete metaphor is: even something as tiny as a butterfly's wing movement in one place could set off a chain of events that eventually becomes a major storm somewhere else.

GRAMMAR CONCEPT APPLIED

Understanding "Its" vs "It's" and When to Use Possessive Apostrophes

This question tests two related concepts about apostrophes:

1. Possessive Pronouns Never Take Apostrophes:

When you want to show that something belongs to "it," use "its" (no apostrophe) - just like other possessive pronouns:

• his book (not hi's book)
• her car (not her's car)
• its wings (not it's wings)
• their house (not their's house)

The word "it's" (with an apostrophe) is ONLY used as a contraction meaning "it is" or "it has":

• It's raining → It is raining
• It's been a long day → It has been a long day

2. Plural Nouns Don't Need Apostrophes Unless They're Possessing Something:

Regular plural nouns are just plural - no apostrophe needed:

• The butterfly flaps its wings (the wings belong to the butterfly, but the wings themselves aren't owning anything)
• The birds sing in the trees (just multiple trees)

Add an apostrophe only when the plural noun possesses something:

• The wings' movement was graceful (the movement belongs to the wings)
• The trees' branches swayed (the branches belong to the trees)

In this question:

• "Its" shows the wings belong to the butterfly (possessive pronoun - no apostrophe)
• "Wings" is simply a plural noun being flapped (no apostrophe needed)
• Result: "its wings"