| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.21 |
| Score | 0% | 64% |
The Sun is a __________-type main-sequence star.
D |
|
S |
|
E |
|
G |
The Sun is a G-type main-sequence star (G2V) but is informally known as a yellow dwarf star. Composed of 73% hydrogen and 25% helium, the hot plasma that makes up the Sun reaches 9,900°F (5,505°C) at the surface. It formed approximately 4.6 billion years ago and makes up 99.86% of the mass in the solar system.
What part of the nervous system controls simple reflexes?
spinal cord |
|
medulla |
|
cerebrum |
|
autonomic |
The spinal cord connects the brain to the body's network of nerves. It carries impulses between all organs and the brain and controls simple reflexes.
The __________ is a system of muscles that allows breathing.
diaphragm |
|
pulmonary |
|
bronchioles |
|
trachea |
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.
In the heart, blood flows from the right __________ to the lungs then back to the heart via the left __________.
atrium, ventricle |
|
ventricle, ventricle |
|
ventricle, atrium |
|
atrium, atrium |
The two largest veins in the body, the venae cavae, pass blood to the right ventricle which pumps the blood to the lungs through the pulmonary artery. Blood picks up oxygen in the lungs and returns it to the left atrium via the pulmonary vein.
50°F is how many °C?
-10 |
|
58 |
|
10 |
|
122 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (50 - 32)\)
\(C° = {5 \over 9} (18)\)
\(C° = {90 \over 9}\)
\(C° = 10\)