Why is water from an aquifer more likely to be cleaner than water from other sources?
A. because it forms where fresh and salt water meet
B. because it receives water directly from precipitation
C. because it rises to the surface near the ocean
D. because pollutants are filtered by rock and soil deep within Earth

Agene with the original sequence of atgtt—tact underwent substitution mutation to form atatt—tact after a few generations. tact is a part of a muscle protein encoding region, and atgtt codes for a digestive enzyme. what will be the effect of this mutation? a. the production of muscle protein will be affected. b. the production of digestive enzymes will be affected. c. the production of both the protein and the enzyme will be affected. d. the production of neither the protein nor the enzyme will be affected.

Which of the following structures is not found in both plant and animal cells? a) chloroplast b) cytoskeleton c) ribosomes d) mitochondria

What type of genetic drift would be simulated if all the beans that were not selected died out?