Answer: directional selection
Explanation: Directional selection occurs when one end of the bell curve has a better fit than the other end. The end that has preferable traits in relation to the environment won't always be the same. The environment can change, and then the opposite end of the bell curve might become preferable.
Answer:
A
Explanation:
A tundra is a cold biome. It contains frost, extremely low temperatures, little precipitation, and few plants and vegetation.
Answer: No i have not yet been affected.
The correct answer is C - carbon dioxide.
The distribution of gases in the earth's atmosphere is as follows:
1. Nitrogen - 78 %
2. Oxygen - 21 %
3. Argon - 0.93 %
4. Carbon dioxide - 0.038%
Nitrogen, oxygen and argon are permanent gases whose percentage in the atmosphere does not change from day to day.
Gases such as carbon dioxide, nitrous oxides, methane, and ozone are known as trace gases which make up 0.1% of the atmosphere.
