| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.25 |
| Score | 0% | 65% |
Regulation of heart rhythm occurs in:
medulla |
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cerebrum |
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nerves |
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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.
Which of the following is true about species groups?
a population is made up of a group of communities |
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an ecosystem is a biological population |
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a biome is a made up of a group of biospheres |
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a community is made up of a group of populations |
A population is a group of organisms of the same species who live in the same area at the same time. A community is a group of populations living and interacting with each other in an area.
Gametes have how many pairs of chromosomes?
4 |
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23 |
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2 |
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46 |
Reproductive (haploid) cells known as gametes have half as many (23) pairs of chromosomes as normal (diploid) cells. When the male gamete (sperm) combines with the female gamete (ovum) through meiosis to form a zygote, each gamete supplies half the chromosomes needed to form the normal diploid cells.
As part of digestion, the liver produces bile which breaks down:
protein |
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fat |
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sugars |
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starches |
The liver produces bile which emulsifies (separates) fat.
The __________ is a system of muscles that allows breathing.
trachea |
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pulmonary |
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diaphragm |
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bronchioles |
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.