Marine biologists studying feeding behaviors have determined that the blue whale can consume approximately 4 tons of krill in a...

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

• Marine biologists
  • studying feeding behaviors
• have determined
  • that the blue whale can consume approximately 4 tons of krill
    • in a single day
    • during the Antarctic feeding season [?] making it the most
      • efficient filter feeder among all marine mammals.

Understanding the Meaning

The sentence tells us about what marine biologists have learned:

• 'Marine biologists studying feeding behaviors have determined that...'
  • Scientists who study how marine animals eat have figured something out.

What did they determine?

• 'the blue whale can consume approximately 4 tons of krill in a single day during the Antarctic feeding season'
  • Blue whales can eat about 4 tons of krill daily when they're feeding in Antarctic waters.

This is where we have the blank. Let's look at the choices:

• A: season. Making (period separates into two sentences)
• B: season, making (comma connects)
• C: season making (no punctuation)
• D: season; making (semicolon connects)

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

• 'making it the most efficient filter feeder among all marine mammals'
  • This is telling us the significance of that 4-ton consumption
  • Eating this much krill is what makes the blue whale the best filter feeder of all marine mammals

What do we notice about the structure here?

• The first part is a complete statement:
  • 'the blue whale can consume approximately 4 tons of krill in a single day during the Antarctic feeding season'
  • This could stand on its own as a complete thought

• The second part - 'making it the most efficient filter feeder' - is NOT a complete sentence
  • It's a descriptive phrase that explains the result or significance of what came before
  • It can't stand alone - it depends on the first part to make sense

When we have a complete statement followed by a descriptive phrase beginning with an "-ing" verb that adds information about the result or consequence, we need a comma to separate them.

So we need: Choice B - "season, making"

The comma correctly connects the complete statement with the descriptive phrase that explains its significance.

GRAMMAR CONCEPT APPLIED

Using Commas with Result/Consequence Phrases (Participial Phrases)

When you have a complete statement followed by a descriptive phrase that begins with an "-ing" verb (called a participial phrase in grammar terms) and explains the result, consequence, or additional information, use a comma to separate them:

Pattern:

• Complete statement + , + -ing phrase describing result/consequence

Example 1:

• The experiment succeeded, proving the hypothesis correct.
• "The experiment succeeded" = complete statement
• "proving the hypothesis correct" = descriptive phrase showing the result

Example 2:

• The storm intensified overnight, causing widespread power outages.
• "The storm intensified overnight" = complete statement
• "causing widespread power outages" = descriptive phrase showing the consequence

In our question:

• The blue whale can consume 4 tons of krill in a single day during the Antarctic feeding season, making it the most efficient filter feeder.
• First part = complete statement about consumption
• "making it the most efficient filter feeder" = descriptive phrase showing what this consumption means/results in
• Comma properly connects them

Key principle: The "-ing" phrase cannot stand alone as a sentence, so it needs a comma (not a period or semicolon) to attach it to the complete statement it describes.