For hundreds of years, there has been an allele for white fur color in rabbits and an allele for black fur color. In the past few decades, a third allele has emerged that gives rabbits brown fur. Where did the new allele most likely come from?

What did TTX do to the voltage-gated sodium channels?

Which of the following is generally required for something to be considered living or alive?

Carbon-12 and carbon-14 both have 6 electrons and 6 protons. Carbon-12 has 6 neutrons, while carbon-14 has 8 neutrons. Carbon-12 and carbon-14 are ______________.

Theories, like the theory of evolution or cell theory, are ______________.

The percentage of erythrocytes in a sample of whole blood is measured by the _______.

Different versions of genes that code for particular versions of traits are called _____________.

Stimulation of the parasympathetic nervous system increases heart rate and the force of contraction.

In exercise 3, activity 1: what happened to the resting membrane potential if the extracellular K+ concentration was increased?

Which of the following nerves carries parasympathetic nervous system signals to the heart?