Explanation:
Variations in the sun's energy reaching Earth
Changes in the reflectivity of Earth’s atmosphere and surface
Changes in the greenhouse effect, which affects the amount of heat retained by Earth’s atmosphere
Answer:
Blood is carried away from the heart by arteries. Blood that is rich in oxygen. Blood that is low in oxygen is returned to the heart by veins. there is more pressure in arteries than in veins.
Answer:
A gas-powered lawn mower is a complex machine because for it to function it does more than one motion. For example, it has a wheel and axle system so it can move when powered. And it has a system of simple machines and other parts that are put together to accomplish the task of cutting grass.
Explanation:
A string of nucleotides that hold information is called a gene. :)
I think if the whale population decreased the surface fish populations would decline due to reduced populations of algae. This can be simply explained by the fact that, if the whale population is decreased, it means that the nitrogen rich feces that is supply nutrients to the algae would also decrease and therefore decrease the population of the algae and as a result the population of of the surface fish would also decline.