The "gray matter" of the brain is largely made up of which of the following?

The correct answer is B. Facilitated diffusion is the passive movement of molecules, including water, across a membrane with the help of specific transport proteins. Water moves through specialized channels called aquaporins during facilitated diffusion.

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.

The correct answer is C. The complementary strand of DNA will have bases that pair with the original strand according to the base-pairing rules. In DNA, adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C). Therefore, the complementary strand reads 3’ TCGATCGCA5’.

The correct answer is C. The renal vein is responsible for draining oxygen-depleted blood from the kidneys. After the kidneys filter waste and excess substances from the blood, the deoxygenated blood is carried away from the kidneys by the renal vein

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. When a volcano erupts, it releases built-up pressure and gases, similar to the fizzing of a can of soda when opened. Both involve the release of pressure and trapped substances, leading to an outward expulsion of materials.

The correct answer is C. 9. The pH is determined by taking the negative logarithm (base 10) of the hydrogen ion concentration ([H+]). In this case, -log(10^(-9)) equals 9, so the pH of the solution is 9.

To find the pH of a solution with a hydrogen ion concentration ([H+]) of \(10^{-9}\) M using the equation \(pH = -\log[H^+]\):

\[ pH = -\log(10^{-9}) \]

Now, since \( \log(10^{-9}) = -9 \), the negative sign before the logarithm makes the value positive:

\[ pH = -(-9) = 9 \]

Therefore, the solution has a pH of 9

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 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 A. A gene is a segment of DNA that contains the instructions for building a specific protein or performing a specific function.