They lack chloroplasts, but have thylakoid membranes, and are thought to have been among the first organisms on Earth.

Which process produces the most variation within a species?

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? A) muscles acids B) lipids C) cellulose D) proteins E) glycogen

Two specialized cells and why they are specialized

Explain why carnivores are subject to biological magnification of substances like DDT and PCBs

What is moisture or water vapor in the atmosphere called?

Coiled tube in which the greatest amount of digestion and absorption take place

Most of the world's food supplies comes from 14 species of crops. Which of these crops are the most important? A) corn, potatoes, and hay B) wheat, rice, and sugarcane C) alfalfa, rice, and wheat D) grasses, bananas, and beans

Tryptophan is an amino acid necessary for E. coli survival and growth. E. coli contain genes coding for enzymes that synthesize tryptophan. These genes are grouped together on a segment of DNA called the tryptophan (trp) operon.

Why does it make sense that the sensors and controller of body temperature reside in the brain? A. Because the brain enables the body's response to temperature changes B. Because deep inside the brain is considered the body's core C.

List the four (4) major groups for the antidepressant medications and the prototype of each one. what are the major differences between the four (4) classes?