| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.39 |
| Score | 0% | 68% |
Gametes have how many pairs of chromosomes?
2 |
|
4 |
|
46 |
|
23 |
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.
Earth's troposphere layer is which of the following?
closest to the surface |
|
hottest |
|
farthest from the surface |
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coldest |
The Earth's atmosphere has several layers starting with the troposphere which is closest in proximity to the surface. Containing most of the Earth's breathable air (oxygen and nitrogen), it's a region with warmer temperatures closer to the surface and cooler temperatures farther away which results in the rising and falling air that generates weather.
Menstruation occurs when:
the fetus is formed |
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the ovum fails to become fertilized |
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the zygote is formed |
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the ovum becomes 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 the food chain, omnivores may be which of the following?
secondary or tertiary consumers |
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primary or tertiary consumers |
|
primary or secondary consumers |
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secondary consumers or scavengers |
Secondary or tertiary consumers may be omnivores.
Earth's history is divided into time periods, which of these is the longest time period?
epoch |
|
eon |
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era |
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age |
The Earth is approximately 4.6 billion years old and its history is divided into time periods based on the events that took place and the forms of life that were dominant during those periods. The largest graduation of time is the eon and each eon is subdivided into eras, eras into periods, periods into epochs, and epochs into ages.