Using the equation pH= -log [H+], a solution with a [H+]= 10-9 M has a pH of which of the following?

The correct answer is C. Biological macromolecules are large, complex molecules essential for life. Nucleic acids, such as DNA and RNA, are examples of biological macromolecules. They are composed of nucleotides and play a crucial role in genetic information storage and transfer.

Nucleic acid, is also an example of a biological macromolecule. Nucleic acids are large molecules made up of nucleotides, which consist of a nitrogenous base, a sugar molecule, and a phosphate group. DNA and RNA are examples of nucleic acids, and they play crucial roles in storing and transmitting genetic information within cells. Therefore, both Protein) and Nucleic acidare correct examples of biological macromolecules.

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.

When a proton is emitted from the nucleus of an atom, the atomic number (Z) decreases by 1 because a proton has a positive charge, and it's effectively removing one positive charge from the nucleus. However, the atomic mass (A) remains the same because protons and neutrons contribute to the atomic mass, and the emission of a proton does not affect the number of neutrons.

Independent assortment occurs during metaphase I when homologous chromosome pairs line up randomly at the cell’s equator. This randomness contributes to genetic variation because the distribution of maternal and paternal chromosomes into gametes is different each time meiosis occurs.

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 D. Water's high specific heat capacity allows it to absorb and store large amounts of heat energy without a significant increase in temperature. Coastal areas, being near large bodies of water, experience less dramatic temperature changes because the water helps moderate temperature fluctuations by absorbing and releasing heat slowly.

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.

Phosphates are found in both DNA and cell membranes. In DNA, they form part of the backbone structure, linking the nucleotides together. In cell membranes, phosphates are a component of phospholipids, which are critical to the membrane's structure and function.

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 B. This option involves a control group (water) and an experimental group (energy drink) to compare the effects. By having a group that does not consume the energy drink, researchers can better attribute any observed differences in running speed to the energy drink itself.