When a child is born with down syndrome, when did the mutation occur?

Nitrogen in the atmosphere must be "fixed" before it can be used by plants. Atmospheric nitrogen is "fixed" by A) plants. B) bacteria. C) bacteria and insects. D) bacteria and lightning.

What is another term for manipulated variable?

Compounds are made up of electrons cells molecules protons

Based on observations, you create steps to test whether the presence of water could accelerate the growth of bread mold. These steps would be A. a conclusion. B. a hypothesis. C. an experiment. D. an analysis.

As an arthropod gets bigger and grows, its exoskeleton gets bigger and grows as well. True False

How do humans become murderers? What are some of the reasons that cause it?

Relate sexual reproduction to evolutionary forces

Where is the glandular swelling on the earthworm found?

A student has a hamburger, french fries, and soda for lunch. Which sequence represents the correct order of events in the nutritional processing of this food?

Explain why the fact that invasive species did not co-evolve with the native species unbalances an ecosystem.