| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.41 |
| Score | 0% | 68% |
Which of the following is not a characteristic of the Sun?
is a yellow dwarf star |
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is composed of hydrogen and helium |
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formed 2.6 billion years ago |
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makes up over 99% of the mass of the solar system |
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.
The __________ is a system of muscles that allows breathing.
diaphragm |
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bronchioles |
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pulmonary |
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trachea |
The diaphragm is a system of muscles that allows breathing. During inhalation, the diaphragm expands and air rushes in to fill the space created. Then, during exhalation, the diaphragm contracts and forces the air back out.
The brain and spinal cord make up the __________ nervous system.
peripheral |
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central |
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autonomic |
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somatic |
The nervous system consists of the brain and spinal cord (central nervous system) and the peripheral nervous system which is the network of nerve cells (neurons) that collect and distribute signals from the central nervous system throughout the body.
Menstruation occurs when:
the ovum becomes fertilized |
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the zygote is formed |
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the fetus is formed |
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the ovum fails to become fertilized |
If the ovum fails to become fertilized, the lining of the uterus sloughs off during menstruation. From puberty to menopause, this cycle of menstruation repeats monthly (except during pregnancy).
In cell biology, what part of the cell contains organelles?
nucleus |
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cell wall |
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cell membrane |
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cytoplasm |
The nucleus of a eukaryotic cell contains the genetic material of the cell and is surrounded by cytoplasm which contains many organelles.