Which gas in Earth's atmosphere helps living things make proteing? O oxygen
O nitrogen
water vapor
O carbonoxide

Sperm pass through the and connect to a short ejaculatory duct. vas deferens prostrates seminiferous tubules none of the above

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?

Substances that can pass through cell membranes by diffusion include a. na ions. b. proteins c. glucose. d. oxygen.