ATI TEAS 7 Science

Correct Answer: B

Rationale: The correct answer is B: 23. In humans, each normal cell contains 23 pairs of chromosomes, making a total of 46 chromosomes. The pairs consist of one chromosome from each parent, ensuring genetic diversity. Choices A, C, and D are incorrect because they do not reflect the accurate number of chromosome pairs in a human cell. Option A (46) is the total number of chromosomes, not pairs. Option C (64) and D (32) are not the correct numbers of chromosome pairs in a human cell.

Correct Answer: A

Rationale: The P wave on an ECG represents atrial depolarization. During the cardiac cycle, the electrical impulse originates in the sinoatrial (SA) node, causing the atria to contract. This depolarization of the atria is reflected as the P wave on the ECG. This occurs before the ventricles depolarize (choice B), repolarize (choice D), or before the atria repolarize (choice C). Therefore, the correct answer is A because the P wave specifically represents atrial depolarization in the cardiac cycle.

Correct Answer: A

Rationale: The correct answer is A: Musca domestica. The scientific name for the common housefly is Musca domestica. "Musca" refers to the genus name, while "domestica" refers to the species name. This specific binomial nomenclature system is used in taxonomy to classify and identify organisms. The other choices are incorrect because: B: Drosophila melanogaster refers to the fruit fly, C: Apis mellifera is the honeybee, and D: Anopheles gambiae is a mosquito species. Each of these options represents different species within the insect family, but only A corresponds to the common housefly.

Correct Answer: A

Rationale: The correct answer is A: Solid. Solids have both a definite volume and a definite shape because the particles are tightly packed and vibrate in fixed positions. This leads to a rigid structure and minimal movement, maintaining the shape and volume. In contrast, liquids (B) have a definite volume but take the shape of their container, gases (C) have neither a definite shape nor volume as they expand to fill the container, and plasmas (D) have no definite shape or volume due to their high energy state.

Correct Answer: A

Rationale: The correct answer is A: Iron (Fe). This is because an element with atomic number 26 corresponds to Iron on the periodic table. The mass number of 56 indicates the total number of protons and neutrons in the nucleus of the atom, which is consistent with the atomic mass of Iron. Choice B, Cobalt, has an atomic number of 27, not 26. Choice C, Nickel, has an atomic number of 28, not 26. Choice D, Manganese, has an atomic number of 25, not 26. Therefore, based on the given atomic number and mass number, Iron is the most likely element.