While one requires oxygen and one does _____ and anaerobic respiration are both forms of cellular respiration—that is, they are...

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

• While one requires oxygen
  • and one does not [?],
• aerobic and anaerobic respiration
  • are both forms of cellular respiration
    • —that is,
      • they are processes by which cells break down glucose
        • to use as energy.

Understanding the Meaning

Let's start reading from the beginning:

"While one requires oxygen and one does not..."

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

• Choice A: "not aerobic" (no punctuation)
• Choice B: "not. Aerobic" (period, capital A)
• Choice C: "not, aerobic" (comma, lowercase a)
• Choice D: "not; aerobic" (semicolon, lowercase a)

So we're deciding what punctuation (if any) should come after "not" and whether "aerobic" should be capitalized.

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

The sentence continues:

• "aerobic and anaerobic respiration are both forms of cellular respiration—that is, they are processes by which cells break down glucose to use as energy."

Now let's understand what this complete sentence is telling us:

• "While one requires oxygen and one does not"
  • This is talking about two types of something
  • One type needs oxygen, the other doesn't
  • The word "while" signals a contrast or comparison

• "aerobic and anaerobic respiration are both forms of cellular respiration"
  • This tells us what those "ones" are - the two types of respiration
  • This is making the main point: despite their difference, they're both forms of cellular respiration

• "that is, they are processes by which cells break down glucose to use as energy"
  • This clarifies what cellular respiration means

What do we notice about the structure here?

• The first part ("While one requires oxygen and one does not") is setting up a contrast
  • It begins with "While," which makes it a dependent clause
  • It can't stand alone as a complete sentence

• The second part ("aerobic and anaerobic respiration are both forms of cellular respiration") is the main clause
  • It's a complete thought with a subject and verb
  • This is the main point of the sentence

• When a dependent clause introduces the sentence, we need a comma to separate it from the main clause

So we need Choice C: "not, aerobic" - a comma to separate the introductory dependent clause from the main clause, with "aerobic" in lowercase because we're continuing the same sentence.

GRAMMAR CONCEPT APPLIED

Using Commas to Separate Introductory Dependent Clauses from Main Clauses

When a sentence begins with a dependent clause (often starting with words like "while," "although," "because," "if," "when," "since"), you need a comma to separate it from the main independent clause that follows.

Pattern:
[Dependent clause with subordinating word], [independent clause].

Examples:

• With subordinating conjunction "although":
  • Dependent clause: "Although the experiment failed"
  • Main clause: "the researchers learned valuable information"
  • Combined: "Although the experiment failed, the researchers learned valuable information."

• With subordinating conjunction "because":
  • Dependent clause: "Because the temperature dropped suddenly"
  • Main clause: "the plants needed protection"
  • Combined: "Because the temperature dropped suddenly, the plants needed protection."

• In our question with "while":
  • Dependent clause: "While one requires oxygen and one does not"
  • Main clause: "aerobic and anaerobic respiration are both forms of cellular respiration"
  • Combined: "While one requires oxygen and one does not, aerobic and anaerobic respiration are both forms of cellular respiration"

Key insight: The dependent clause (sometimes called a subordinate clause in grammar terms) sets up context or provides background, while the main clause delivers the primary message. The comma signals to the reader: "The introduction is complete; here comes the main point."