Water molecules enter cells by which of the following transport mechanisms?

The correct answer is A. Browning of an apple is often caused by enzymes such as polyphenol oxidase. Lemon juice has a low pH, creating an acidic environment that inhibits the activity of these enzymes and prevents browning.

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. Atoms become cations by losing electrons. Potassium has one electron in its outermost shell, and it is more likely to lose that electron to achieve a stable, cationic state. Fluorine, helium, and oxygen are more likely to gain electrons and form anions.

The correct answer is A. This option describes a chemical reaction known as the reaction of water with sodium, producing hydrogen gas. Chemical reactions involve the breaking and forming of chemical bonds, and in this case, sodium reacts with water to produce hydrogen gas and sodium hydroxide.

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 hip bone (or pelvis) in adults is formed by the fusion of three separate bones: the ilium, ischium, and pubis. This fusion occurs during adolescence and results in a single, solid structure.

The correct answer is D. The typical pathway of blood flow involves arteries branching into arterioles, which further branch into capillaries, facilitating the exchange of nutrients and gases with the organ's tissues.

The correct answer is B. The phenotypic ratio of 50% green pods and 50% yellow pods indicates that the genotype of the parent with green pods is heterozygous (Gg), and the genotype of the parent with yellow pods is homozygous recessive (gg). The cross would be Gg x gg.

The correct answer is B. Gray matter in the brain primarily consists of neuron cell bodies, dendrites, and unmyelinated axons. It is involved in information processing and integration.

The correct answer is B. Objects A and B have the same mass, but B falls faster because it has less air resistance. Objects C and D have different masses, but C falls faster because it has a higher mass-to-surface-area ratio, which reduces the effect of air resistance.