Question

"Why are yawns contagious? We asked a scientist"%0D%0Aby Teresa Carey%0D%0A%0D%0AWhy do we yawn?%0D%0AThere 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. %0D%0A%0D%0AExcess 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. %0D%0A%0D%0AOther proposals state the purpose of yawning is to cool the brain, or to stretch internal organs like tissues Use the passage from “Why are yawns contagious? We asked a scientist.” to answer the question.%0D%0A%0D%0AEffect: We yawn.%0D%0A%0D%0ACause: to quickly expel carbon dioxide%0D%0A%0D%0ACause: to drive oxygen-enriched blood to the brain%0D%0A%0D%0ACause: to stretch internal organs%0D%0A%0D%0ACause: ?%0D%0A%0D%0ACause: ?%0D%0A%0D%0ABased on the information in the passage, which cause completes the graphic organizer? Select the two correct answers.%0D%0A%0D%0A(1 point)%0D%0AResponses%0D%0A%0D%0Ato cool the brain%0D%0Ato cool the brain%0D%0A%0D%0Ato build up oxygen%0D%0Ato build up oxygen%0D%0A%0D%0Ato increase the frequency of deep breaths%0D%0Ato increase the frequency of deep breaths%0D%0A%0D%0Ato compress facial muscles%0D%0Ato compress facial muscles%0D%0A%0D%0Ato increase adenosine levels

Answer 1

Based on the information in the passage, the two correct answers that complete the graphic organizer are:

1. **to cool the brain**
2. **to build up oxygen**

These responses align with the theories mentioned in the passage regarding the causes of yawning.