How much energy is available to organisms on the 5th trophic level compared with this on the 1st? How does this determine how long a food chain can be?

Why do scientists classify fish, amphibians, reptiles, birds, and mammals together in one group?

1. About how long are these 12s genes in terms of the number of nucleotides 2. Is it surprising that these genes would be of such similar lengths despite being from different species? Explain.

Harmful environmental agents cause an average of 4-5 percent of birth defects.

What would happen when an artificial K + channel is inserted into an axon membrane at resting potential? Answer questions 1-4 by selecting only from the three answer choices to the left of each question.

Organisms are taxonomically classified based on structural and genetic characteristics. Chimpanzees, or Pan troglodytes, are hominids found mainly in equatorial Africa.

Ozone hole refers to ... ? A. hole in ozone layer B. decrease in the ozone layer in troposphere C. decrease in thickness of ozone layer in stratosphere D. increase in the thickness of ozone layer in troposphere

Chemicals used in chemotherapy treatments to fight cancer can also harm cells in hair follicles and bone marrow. What characteristic do these cells most likely share with cancerous cells? A.) They form tumors. B.) They spread through the blood. C.

Binary fission is a process through which A. all cells divide. B. eukaryotic cells divide. C. prokaryotic cells divide. D. cellular DNA is cut in half.

Describe how this algal bloom might alter the local nitrogen cycle in that ecosystem.

What are the reactants in the equation for cellular respiration?