Mometrix TEAS 7 science practice test

Correct Answer: B

Rationale: The Hardy-Weinberg equilibrium describes a theoretical population in which allele frequencies remain constant from generation to generation, indicating that the population is not evolving. This equilibrium occurs under specific conditions: no mutation, no gene flow, random mating, a large population size, and no natural selection. In this scenario, all genotypes are in proportion to the allele frequencies, and genetic diversity is maintained. Options A, C, and D do not accurately describe a population in Hardy-Weinberg equilibrium. Option A suggests rapid evolution due to strong directional selection, which would disrupt the equilibrium. Option C mentions a founder effect, which can reduce genetic diversity but is not a characteristic of a population in Hardy-Weinberg equilibrium. Option D describes a population dominated by a single homozygous genotype, which also does not align with the genetic diversity seen in a population at Hardy-Weinberg equilibrium.

Correct Answer: B

Rationale: The mass number of an element represents the total number of protons and neutrons in an atom's nucleus. It specifically focuses on the number of neutrons in an atom's nucleus, which contributes to the overall mass of the atom. Therefore, the mass number is not solely determined by the number of protons, electrons, or isotopes. Choice A is incorrect because it refers to the atomic number, which is the number of protons in an atom's nucleus. Choice C is incorrect as the number of electrons in the valence shell is related to the atom's reactivity and bonding behavior, not the mass number. Choice D is incorrect because the mass number does not represent the number of isotopes of an element, but rather the sum of protons and neutrons in an atom's nucleus. Thus, option B, the number of neutrons in an atom's nucleus, is the correct choice.

Correct Answer: D

Rationale: Newton's rings are a series of concentric colored rings observed when light is reflected between a spherical surface and a flat surface. This phenomenon is a result of thin-film interference, where light waves reflecting off the two surfaces interfere with each other constructively or destructively, leading to the observed pattern of rings. Diffraction, polarization, and the Doppler effect are not related to the specific phenomenon of Newton's rings. Diffraction refers to the bending of waves around obstacles, polarization deals with the orientation of electromagnetic waves, and the Doppler effect relates to the change in frequency of waves due to motion. Therefore, the correct answer is thin-film interference, as it precisely describes the phenomenon observed in Newton's rings.

Correct Answer: D

Rationale: The correct answer is D: Sinoatrial node (located within the heart). The involuntary, rhythmic contractions of the heart muscle are controlled by a specialized group of cells located within the heart called the sinoatrial node (SA node). The SA node acts as the heart's natural pacemaker, producing electrical impulses that regulate the heart rate and synchronize the contractions of the heart muscle. Choices A, B, and C (Lungs, Brain, Spinal cord) are not responsible for directly influencing the rhythmic contractions of the heart muscle.

Correct Answer: C

Rationale: The primary function of the ovaries in the female reproductive system is to produce eggs (ova). Ovaries are responsible for the production of female gametes. Additionally, they secrete hormones such as estrogen and progesterone, which are essential for the menstrual cycle and pregnancy. Transporting sperm to the uterus is the function of the fallopian tubes, not the ovaries. Producing milk for feeding offspring is the role of the mammary glands, not the ovaries. Regulating urination is a function associated with the urinary system, not the female reproductive system or the ovaries.