How are electrons moved from photosystem II to photosystem I in photosynthesis?

Why is it colder in winter than summer? Other than, "Because the earth's axis is tilted, meaning the sun's rays hit the earth at a shallow angle." I need TWO reasons. TWO!

Which is an example of geographic isolation? A) A species of chipmunk becomes extinct because of a lack of food. B) Two groups of albatross live on separate islands but commonly cross from one island to the other.

Mast cells play what key role in initiating an immune response?

What is a community of living things together with their environment called? A. retrosystem B. ecosystem C. exosphere D. biosphere

Why can a signaling molecule cause different responses in different cells?

What type of bond holds this type of molecule together?

A geneticist found that s particular mutation had no effect on the protein coded by a gene. What do you think is the most likely type of mutation in this gene? and why?

What is stored energy called

The Mohs scale is used to determine a mineral's

Hybrids between grizzly and polar bears have been moving farther north. What do you predict about the migration of their hybrid zone over time? A. It will eventually completely overlap with the range of polar bears. B.