| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.91 |
| Score | 0% | 58% |
In the food chain, omnivores may be which of the following?
secondary or tertiary consumers |
|
primary or secondary consumers |
|
secondary consumers or scavengers |
|
primary or tertiary consumers |
Secondary or tertiary consumers may be omnivores.
Gametes have how many pairs of chromosomes?
46 |
|
2 |
|
23 |
|
4 |
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.
The __________ is a system of muscles that allows breathing.
trachea |
|
bronchioles |
|
pulmonary |
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diaphragm |
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.
Which of the following substances gives up negatively charged hydroxide ions (OH-) when dissolved in water?
hydrogen |
|
base |
|
ion |
|
acid |
An acid is a substance that gives up positively charged hydrogen ions (H+) when dissolved in water. A base (alkaline) gives up negatively charged hydroxide ions (OH-) when dissolved in water. pH is a scale that measures of how basic or acidic a solution is. Numbered from 0 to 14, solutions with a pH of 7 are neutral, less than 7 are acidic, more than 7 are alkaline.
The angle of reflection is equal to which the following?
90° |
|
refractive index |
|
focal point |
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angle of incidence |
The law of reflection specifies how waves, including light waves, bounce off of surfaces. Specifically, the angle of incidence of the approaching wave is equal to the angle of reflection of the reflected wave as measured from a line perpendicular (90°) to the surface.