Electrons lost by photosystem I are replaced by electrons released from the a. photolysis of water

b.
photosystem II

c.
Light-independent reactions

d.
thylakoid membrane

Look at the following answer choices and determine which belongs in the both category. testable, can be disproven explains natural phenomena, has evidence to support it prediction, tentative, one or more scientists working together well established, many different scientists working independently, highly reliable

Living cells cannot use heat to provide the activation energy for biochemical reactions because which choice(s) complete the sentence correctly? a) answer choice ii. eliminate b) answer choices ii and iv. c) answer choice iii and iv. d) all answers can complete the sentence.

Astudent is looking through a microscope at some cells of an onion root tip. many of these cells are undergoing division since the root tip grows quickly and requires more cells. which cell most recently underwent metaphase? w x y z