| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.87 |
| Score | 0% | 57% |
Which of the following is not a characteristic of the Sun?
is composed of hydrogen and helium |
|
makes up over 99% of the mass of the solar system |
|
formed 2.6 billion years ago |
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is a yellow dwarf star |
The Sun is a G-type main-sequence star (G2V) but is informally known as a yellow dwarf star. Composed of 73% hydrogen and 25% helium, the hot plasma that makes up the Sun reaches 9,900°F (5,505°C) at the surface. It formed approximately 4.6 billion years ago and makes up 99.86% of the mass in the solar system.
In the heart, blood flows from the right __________ to the lungs then back to the heart via the left __________.
ventricle, ventricle |
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ventricle, atrium |
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atrium, atrium |
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atrium, ventricle |
The two largest veins in the body, the venae cavae, pass blood to the right ventricle which pumps the blood to the lungs through the pulmonary artery. Blood picks up oxygen in the lungs and returns it to the left atrium via the pulmonary vein.
What part of the nervous system controls simple reflexes?
spinal cord |
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medulla |
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cerebrum |
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autonomic |
The spinal cord connects the brain to the body's network of nerves. It carries impulses between all organs and the brain and controls simple reflexes.
In cell biology, where does DNA replication take place?
nucleus |
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cytoplasm |
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mitochondria |
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Golgi apparatus |
The cell nucleus contains the genetic material of the cell and is where DNA replication takes place.
Respiration is the process by which __________ absorb oxygen and eliminate carbon dioxide.
blood cells |
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bronchioles |
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diaphragms |
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capillaries |
The respiratory system manages respiration which is the process by which blood cells absorb oxygen and eliminate carbon dioxide.