MCAT Question of the Day

Correct Answer: A. I only.

ATP is the only product formed in both glycolysis and the ETC. Item II is false: NADH is produced only in glycolysis, and it is used in the ETC. Items III and IV are false: oxygen and FADH2 are not produced in either of these processes.

Subscribe below to receive the MCAT Question of the Day delivered straight to your inbox every morning.

Correct Answer: D. A need to maintain their tissues in a hypoosmotic state.

Different organisms have different needs to maintain their water balance, depending on the environment they live in. Bony fish living in saltwater maintain hypoosmotic body fluids. The hyperosmotic water they live in tends to draw the water out of their body by osmosis. They can obtain water by ingesting ocean water, but this raises their internal osmolarity. They excrete salt, then, to lower their internal osmolarity.

Subscribe below to receive the MCAT Question of the Day delivered straight to your inbox every morning.

Correct Answer: D.
It should be known that the semiconservative hypothesis refers to the supported model of how DNA replication works. This occurs at the beginning of mitosis or meiosis, when chromatids are synthesized.

Subscribe below to receive the MCAT Question of the Day delivered straight to your inbox every morning.

Correct Answer: A.

DNA polymerase is the enzyme involved with bringing DNA nucleotides into place during DNA replication. In the cell cycle, this occurs during the S phase of interphase.

Subscribe below to receive the MCAT Question of the Day delivered straight to your inbox every morning.

Correct Answer: D.

This question refers to kidney function and osmotic interaction. A hypotonic filtrate has more water than solute and passes through a hypertonic tissue (more solute, less water), so water will move from the filtrate to the tissue.

Subscribe below to receive the MCAT Question of the Day delivered straight to your inbox every morning.

Correct Answer: B. Erythrocytes.

Erythrocytes (or red blood cells) do not contain a nucleus and thus contains no DNA. This is to maximize the amount of O2 an erythrocyte can carry.

Subscribe below to receive the MCAT Question of the Day delivered straight to your inbox every morning.

Correct Answer: C. Both maternal and embryonic tissues.

The chorion forms from cells of the trophoblast, an embryonic tissue. The endometrium is the inner lining of the uterus, a maternal tissue. Therefore, the placenta consists of tissues derived from both.

Subscribe below to receive the MCAT Question of the Day delivered straight to your inbox every morning.

Correct Answer: C. Additions and deletions.

Substitutions affect only one codon, and as a result, only one amino acid. Both additions and deletions affect the codons in which they occur, and every codon thereafter (frameshift mutations).

Subscribe below to receive the MCAT Question of the Day delivered straight to your inbox every morning.

Correct Answer: B. These organisms cannot use oxygen as their final electron acceptor.

Obligate anaerobes require the absence of oxygen to survive.

Correct Answer: C. Skeletal muscles.

Motor neurons, by definition, carry impulses from the CNS to the effectors. Only choice C is a plausible answer.