How does an adaptation contribute to change in a species over time?

An easy way to calculate the amount of energy available at each level is to what?

Which of the following particles always has a positive charge? a. electronb. neutron c. proton d. ion

Vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a.) antibody, antibiotic b.) antigen, antibody c.)antibiotic, antibody d.)antibody, antigen