| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.86 |
| Score | 0% | 57% |
In the food chain, omnivores may be which of the following?
primary or secondary consumers |
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primary or tertiary consumers |
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secondary consumers or scavengers |
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secondary or tertiary consumers |
Secondary or tertiary consumers may be omnivores.
Which of these parts of digestion takes place in the mouth?
breaking down starches |
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breaking down proteins |
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absorbing nutrients |
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breaking down fats |
Digestion begins in the mouth where the teeth and tongue break down food mechanically through chewing and saliva, via the enzyme salivary amylase, starts to break starches down chemically. From the mouth, food travels down the esophagus where contractions push the food into the stomach.
Vector quantities are fully described by which of the following?
a direction only |
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a magnitude and a direction |
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a magnitude only |
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a direction and a polarity |
Velocity and displacement are vector quantities which means each is fully described by both a magnitude and a direction. In contrast, scalar quantities are quantities that are fully described by a magnitude only. A variable indicating a vector quantity will often be shown with an arrow symbol: \(\vec{v}\)
The two heart chambers that collect blood are called:
valves |
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atria |
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ventricles |
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aorta |
The heart is the organ that drives the circulatory system. In humans, it consists of four chambers with two that collect blood called atria and two that pump blood called ventricles. The heart's valves prevent blood pumped out of the ventricles from flowing back into the heart.
Which of the following is not true about mass and weight?
mass is the amount of matter something has |
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weight depends on the location where it is measured |
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weight is the force exerted on an object by gravity |
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mass depends on the location where it is measured |
Mass is the amount of matter something has while weight is the force exerted on an object's mass by gravity. So, although a person's mass doesn't change when going from the Earth to the Moon, their weight will decrease because the force of the Moon's gravity is much less than that of Earth.