| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.62 |
| Score | 0% | 72% |
The hottest of Earth's atmospheric layers is which of the following?
stratosphere |
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thermosphere |
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troposphere |
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mesosphere |
Temperatures again increase with altitude in the thermosphere which is the hottest (4,530 °F / 2,500 °C) atmospheric layer due to direct exposure to the Sun's radiation. However, the gas in this layer is highly diluted so even though the atoms of gas may be very high in temperature, there are too few of them to effectively transfer much heat.
A subatomic particle found in the nucleus of an atom. It carries no electric charge. This desribes which of the following?
proton |
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atom |
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electron |
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neutron |
A neutron is a subatomic particle found in the nucleus of an atom. It is neutral as it carries no electric charge.
The connective tissue that connects bones to other bones at joints is called:
ligaments |
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knuckles |
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tendons |
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cartilage |
Tough fibrous cords of connective tissue called tendons connect muscles to the skeleton while another type of connective tissue called ligaments connect bones to other bones at joints (elbow, knee, fingers, spinal column).
What part of the nervous system is responsible for controlling involuntary actions like breathing, swallowing, and heartbeat?
cerebrum |
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spinal cord |
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medulla |
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cerebellum |
Part of the brainstem, the medulla is the connection between the brain and the spinal cord. It controls involuntary actions like breathing, swallowing, and heartbeat.
Menstruation occurs when:
the ovum fails to become fertilized |
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the ovum becomes fertilized |
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the fetus is formed |
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the zygote is formed |
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).