Question
"Why Are Yawns Contagious? We Asked a Scientist"
by Teresa Carey
There is no scientific consensus on why we yawn.
One theory argues that when humans are tired, we stop taking deep breaths, which causes a build-up of carbon dioxide in the body, said Douglas Parham, a speech scientist at Wichita State University. A yawn might be a special kind of respiration, Parham said. It builds up oxygen quickly, while expelling carbon dioxide, even more than a deep breath.
Excess carbon dioxide and other chemical changes, such as a drop in oxygen or increase in a compound called adenosine, could also act as “yawn gates,” said James Giordano, a neuroethicist and neuroscientist at Georgetown University. These chemicals send out a signal that triggers a yawn. By yawning, we compress the muscles of the face, driving oxygen-enriched blood to the brain, Giordano said.
Other proposals state the purpose of yawning is to cool the brain, or to stretch internal organs like tissues and lungs, helping the body to liven up.
Use the passage to answer the question.
What is the purpose of the transitions “One theory” and “other proposals” in this excerpt?
- To group together explanations to the same question
(explain why this is correct in simple words and in 2 sentences)
by Teresa Carey
There is no scientific consensus on why we yawn.
One theory argues that when humans are tired, we stop taking deep breaths, which causes a build-up of carbon dioxide in the body, said Douglas Parham, a speech scientist at Wichita State University. A yawn might be a special kind of respiration, Parham said. It builds up oxygen quickly, while expelling carbon dioxide, even more than a deep breath.
Excess carbon dioxide and other chemical changes, such as a drop in oxygen or increase in a compound called adenosine, could also act as “yawn gates,” said James Giordano, a neuroethicist and neuroscientist at Georgetown University. These chemicals send out a signal that triggers a yawn. By yawning, we compress the muscles of the face, driving oxygen-enriched blood to the brain, Giordano said.
Other proposals state the purpose of yawning is to cool the brain, or to stretch internal organs like tissues and lungs, helping the body to liven up.
Use the passage to answer the question.
What is the purpose of the transitions “One theory” and “other proposals” in this excerpt?
- To group together explanations to the same question
(explain why this is correct in simple words and in 2 sentences)
Answers
GPT-4o mini
The transitions "One theory" and "other proposals" are used to organize different explanations about why yawning occurs. They help clarify that the first statement presents a specific explanation, while the subsequent statement introduces additional ideas, making it easier for readers to understand the ongoing discussion about the topic.