| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.09 |
| Score | 0% | 62% |
The Sun is a __________-type main-sequence star.
E |
|
D |
|
G |
|
S |
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.
Which of the following substances gives up positively charged hydrogen ions (H+) when dissolved in water?
base |
|
solution |
|
acid |
|
alkaline |
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.
A dominant trait will be expressed when paired with:
a dominant trait |
|
a recessive trait |
|
a gene |
|
a chromosome |
The traits represented by genes are inherited independently of each other (one from the male and one from the female gamete) and a trait can be dominant or recessive. A dominant trait will be expressed when paired with a recessive trait while two copies of a recessive trait (one from each parent) must be present for the recessive trait to be expressed.
During digestion, the kidneys filter substances from the blood. Which of the following is not filtered by the kidneys?
salt |
|
water |
|
fats |
|
minerals |
Chemical waste like excess water, minerals, and salt are filtered from the blood by the kidneys and secreted into the urine. Urine is transported from the kidneys to the bladder through ureters.
-40°F is how many °C?
\({40 \over 9}\) |
|
-40 |
|
-8 |
|
\(-{40 \over 9}\) |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (-40 - 32)\)
\(C° = {5 \over 9} (-72) = {{-72 \times 5} \over 9}\)
\(C° = {-360 \over 9}\)
\(C° = -40\)