Escherichia coli is plated on nutrient agar plates that each contain a different type of antibiotic. The shaded area represents the growth of the bacteria. Which of the following plates contains bacteria that were most resistant to the antibiotic?

A.

B.

C.

D.

The correct answer is D. Mitochondria are the cellular organelles responsible for the production of ATP (adenosine triphosphate) through the process of cellular respiration.

The correct answer is A. Increasing the surface area of a solid reactant by grinding it to a powder exposes more particles to the reactants, enhancing their chances of colliding and increasing the reaction rate. The other options would generally decrease the rate of the reaction.

The correct answer is B. The vermiform appendix is a small, tube-like structure that extends from the cecum, which is the first part of the large intestine. It is not associated with the jejunum, rectum, or ischium.

The correct answer is B. Electrons are much lighter than protons and neutrons and have a negligible mass compared to them. Therefore, when calculating the atomic mass number, electrons are typically not considered.

The correct answer is C. Chlorine molecule (Cl2) has only one covalent bond between the two chlorine atoms, which share one pair of electrons. The other molecules have more covalent bonds: water has two, methane has four, and ammonia has three.

The correct answer is A. The endocardium is the innermost layer of tissue that lines the interior surfaces of the heart, providing a smooth surface for blood flow. The myocardium is the middle muscular layer, the pericardium is the outer protective sac, and the epicardium is the outermost layer covering the heart.

The correct answer is A. Endocrine glands secrete hormones directly into the bloodstream without ducts, while exocrine glands have ducts through which their secretions are transported to specific locations. This fundamental difference in the mode of secretion distinguishes endocrine from exocrine glands.

The correct answer is A. Melanocytes are responsible for producing the pigment melanin and transferring pigment granules to adjacent epidermal cells, particularly keratinocytes. This process contributes to the coloration of the skin.

The correct answer is B. Parathyroid hormone (PTH) regulates blood calcium levels by stimulating the release of calcium from bones, reabsorption of calcium in the kidneys, and absorption of calcium in the intestines. Norepinephrine, growth hormone, and melatonin do not play a primary role in calcium regulation.

The correct answer is D. The hip joint allows for a wide range of motion and is characterized by a ball-and-socket structure, where the rounded head of the femur fits into the cup-like socket of the acetabulum in the pelvis. This type of joint permits movement in multiple directions.