Systems encountered in nature at Earth's surface, such as a forest, are:. a. closed systems in terms of energy.
b. open systems in terms of energy. open systems in terms of matter.
c. both open systems in terms of energy and open systems in terms of matter.
d. both closed systems in terms of energy and open systems in terms of matter.

The pressurized plants and fungi mentioned in the video have some surprising similarities. what differences would you expect them to have?

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

Fill in the blank with the correct sphere label. a: ⇒ geosphere b: ⇒ biosphere c: ⇒ hydrosphere