In 1977, oceanographers discovered hydrothermal vents releasing superheated water from the ocean ______ near these thermal features, extremophile bact...

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

• In 1977,
  • oceanographers
    • discovered hydrothermal vents
      • releasing superheated water
        • from the ocean floor [?]
          • near these thermal features,
• extremophile bacteria
  • thrive
    • in conditions
      • previously thought uninhabitable.

Understanding the Meaning

Let's start from the beginning and understand what this passage is telling us:

The sentence opens with:

• 'In 1977, oceanographers discovered hydrothermal vents releasing superheated water from the ocean floor'

This gives us a complete picture of a discovery:

• Scientists found these special vents on the ocean floor
• These vents release extremely hot water

Now we reach the blank. Let's look at what our choices are giving us:

• We need to decide on the punctuation after 'floor'
• And whether the word 'clustered' should be capitalized or not

To see what works here, let's read the rest and understand what it's saying!

The passage continues:

• 'clustered near these thermal features, extremophile bacteria thrive in conditions previously thought uninhabitable'

Now let's really understand what this second part is telling us:

• 'Clustered near these thermal features'
  • 'These thermal features' refers back to the hydrothermal vents
  • Something is clustered (grouped together) near these vents
  • What's clustered? The bacteria mentioned next

• 'extremophile bacteria thrive in conditions previously thought uninhabitable'
  • These are special bacteria that can live in extreme conditions
  • They thrive (grow well) in places scientists thought nothing could live

So the complete picture is:

• First part: Scientists discovered hydrothermal vents in 1977
• Second part: Bacteria cluster near these vents and thrive in these extreme conditions

What do we notice about the structure here?

• The first part is a complete thought
  • It has a subject (oceanographers)
  • It has a verb (discovered)
  • It expresses a complete idea about a discovery

• The second part is also a complete thought
  • 'Clustered near these thermal features' describes where the bacteria are located
  • 'extremophile bacteria thrive...' is the main statement with its own subject and verb
  • It expresses a complete idea about these bacteria

• These are two separate, complete thoughts that could each stand alone as sentences

When we have two complete thoughts like this, we need to separate them into two distinct sentences.

So we need: Choice B - floor. Clustered

The period creates the proper separation between these two independent ideas, and 'Clustered' is capitalized because it starts a new sentence.

GRAMMAR CONCEPT APPLIED

Separating Complete Thoughts into Distinct Sentences

When you have two complete thoughts (called independent clauses in grammar terms) that each have their own subject and verb and express complete ideas, you need to separate them properly. The strongest separation is a period, creating two sentences:

Pattern:

• Complete thought #1: Subject + Verb + Complete idea
• [PERIOD]
• Complete thought #2: Subject + Verb + Complete idea

Example from another context:

• Wrong: 'The storm intensified rapidly, residents evacuated immediately'
  • Two complete thoughts incorrectly separated by just a comma
• Correct: 'The storm intensified rapidly. Residents evacuated immediately.'
  • Two complete thoughts properly separated by a period

In our question:

• Complete thought #1: 'In 1977, oceanographers discovered hydrothermal vents releasing superheated water from the ocean floor'
  • Subject: oceanographers
  • Verb: discovered
  • Complete idea about the discovery

• [PERIOD NEEDED HERE]

• Complete thought #2: 'Clustered near these thermal features, extremophile bacteria thrive in conditions previously thought uninhabitable'
  • Descriptive phrase: 'Clustered near these thermal features'
  • Subject: extremophile bacteria
  • Verb: thrive
  • Complete idea about the bacteria

Since both parts express complete, independent ideas, they need to be separated as two distinct sentences with a period.