Which organ is essential in circulating oxygen throughout the body?

a. liver

b. heart

c. lung

d. kidney

Explain why lactic acid fermentation causes your muscles to "burn"

What is true of an object that is in free fall? No forces are acting on it. The forces of thrust and gravity balance one another. The forces of air resistance and gravity balance one another. Only the force of gravity is accelerating it.

Which of the following statements about mutations is/are incorrect? Choose all that apply. -Mutations arise from sources other than just mistakes made during DNA replication.

The 3-dimensional structure of a protein polypeptide chain or chains may be locked in place by other stronger bonds. These bonds are formed between components of the - R groups of the amino acid residues.

Which statement best describes the cycling of carbon between the atmosphere and hydrosphere? A. Trees and plants releasing carbon through respiration B. Volcanic activity releasing carbon into the atmosphere C.

Which of the following represents the treatment option most likely to avoid the evolution of drug-resistant HIV (assuming no drug interactions or side effects) ?

Which of the following connective tissues is richly vascularized and consists of more cells than extracellular matrix? A) Adipose b) Dense regular C) Areolar D) Hyaline cartilage

Humans and apes have five fingers they can use to grasp objects. do you think these are analogous or homologous structures? explain your answer.

During which two minute time period is the temperature of the water changing fastest?

The human body is made up of: nucleus absorption cells neurons