A barrier made up of several layers that stops pathogens from entering the body is

a. the skin. b. white blood cells. c. cilia. d. mucus.

The nontaxonomic term sea slug encompasses a wide variety of marine gastropods. One feature they share as adults is the lack of a shell. We might think, therefore, that they represent defenseless morsels for predators.

In an eight-cell embryo of an organism, the cells of the upper tier are aligned directly over the cells of the lower tier. Which organism is it likely to be? earthworm snail starfish

Which of the following statements best exemplifies the difference between a population and an individual? a. Genetic changes do not occur within the individual. b.

How did the formation of the ozone layer contribute to the existence of life on Earth? O It blocked the Sun's harmful UV rays. O It caused water vapor to cool, condense and collect.

Classify each method or description of membrane transport as either passive or active by dragging the label to the correct box.

If the DNA nucleotides read 3'-ATG-CGT-GAC-5', the amino acid sequence of the resulting polypeptide (protein) would be what?

The movement of individuals into an area is called

The type of antimicrobial drug that would be least toxic to humans is a drug thatA) Inhibits protein synthesisB) Disrupts the cytoplasmic membraneC) Inhibits nucleic acid synthesisD) Inhibits cell wall synthesis

populations around the globe. If you were a scientist studying this fungus and wanted to know if it could infect a new frog species, how would you conduct your experiment?

Pregnancy comes with a unique set of diet and lifestyle guidelines. Some substances are particularly beneficial for the mother or baby, others are harmful, and some should be used with caution. Drag the appropriate items to their respective bins.