1. If your test tubes actually contained strontium-90, which one (or ones) would have been safe using the 1% guideline?

Why is excretion necessary to maintain homeostasis?

As a result of wildfires, in grasslands. a) tree growth increases b) grass growth increases c) soil quality decreases d) invertebrate variety decreases

The nervous system interacts with the endocrine system by a. using hormones as connections b. sending nerve impulses directly to glands c. using neuroendocrine cells as connections d. sending neurotransmitters directly to neurons