What does the biological species concept use as the primary criterion for determining species boundaries?

a. mole?

Birds almost always migrate A: during the day B: at night C: on cloudy days D: at noon

True or False: Volcanic activity was more frequent in earth's past than it is today. Question 3 options: True False

Genes pass from parents to offspring on what

Although controversial at first, the germ theory of disease proposed that microorganisms were the cause of many diseases. Which of these was a result of the general acceptance that microorganisms cause disease?

How do rocks along the central valley of the mid-ocean ridge provide evidence of sea-floor spreading

If a cat has a mass of 4kg and is sitting 1.5m above the ground. What is the potential energy of the cat?

What is the body of a sponge is covered with many small opening?

The blueprint of genetic code is known as

2. Energy can change forms. When it does, some energy is changed to a form that cannot do work. A) DNA B) motion C) heat D) fat

Can recessive genes be expressed if the gene pair is heterozygous and why?