In which of the following areas does protein breakdown begin in the human body?
A. Mouth
B. Stomach
C. Small intestine D. Large intestine - (correct Answer) - B. The stomach
The stomach is the first place in the digestive system in which proteinases are produced.
Which of the following cell types is responsible for the production of soluble antibodies? A. Cytotoxic T cell B. Macrophage cell C. Helper T cell
D. B cell - (correct Answer) - D. B cell
The production of antibodies by B cells is part of the humoral response to antigens.
Which of the following organ systems is responsible for transporting nutrients, water, and other substances throughout the human body? A. Respiratory
B. Immune
C. Nervous
D. Circulatory - (correct Answer) - D. Circulatory
The heart pumping blood through the arteries, capillaries, and veins provides the means of transporting substances throughout the body.
Which of the following is characteristic of the human organism? A. Autotrophic with a genome stored in DNA B. Heterotrophic with a genome stored in DNA
C. Autotrophic with a genome stored in RNA D. Heterotrophic with a genome stored in RNA - (correct Answer) - B. Heterotrophic with a genome stored in DNA
Humans consume rather than manufacture nutrient molecules (heterotrophic) and human genes are encoded in DNA.
Which of the following is the function of the lymph nodes in mammals?
A. Pump oxygen into tissue spaces
B. store extra glucose for emergencies C. Synthesize hemoglobin for erythrocytes D. Filter debris from intracellular spaces - (correct Answer) - D. Filter debris from intracellular spaces
Lymph notes filter debris, lymphocytes, and pathogens from intracellular fluid.
The bands in the muscle sarcomere are formed by actin and which of the following other proteins?
A. Myosin
B. Dynein
C. Keratin
D. Myofibril - (correct Answer) - A. Myosin
Myosin contains "heads" that contact actin and pull the actin fibers together in an ATP- dependent mechanism that causes muscles to contract.
Which of the following structures within a human cell is responsible for recycling the materials no longer functional or needed within the cell? A. Ribosome
B. Lysosome
C. Mitochondrion