ATI TEAS Science

Correct Answer: A

Rationale: The correct answer is A: DNA mutation. An alteration in the normal gene sequence is referred to as a mutation, which can result from changes in the DNA sequence. Mutations can lead to variations in genetic information. Gene migration (B) refers to the movement of genes between populations. Polygenic inheritance (C) involves the contribution of multiple genes to a trait. Incomplete dominance (D) is a genetic pattern where the phenotype of a heterozygous individual is intermediate between the two homozygous phenotypes.

Correct Answer: B

Rationale: The final phase of mitosis is Telophase. In Telophase, the nuclear envelope reforms around the separated chromatids, chromosomes unwind into chromatin, and the nucleolus reappears. This marks the end of nuclear division. Prophase is the initial phase where chromosomes condense. Anaphase is when chromatids separate and move to opposite poles. Metaphase is when chromatids align at the center. Telophase is the only phase where the nuclear envelope reforms and the nuclear division is completed.

Correct Answer: B

Rationale: The correct answer is B (50%). When an A heterozygote (IAi) individual and an O (ii) individual have a child, the possible genotypes of the offspring are IAi (A blood type) and ii (O blood type). Since A and O blood types are determined by codominant and recessive alleles respectively, the child has a 50% chance of inheriting the A allele from the A heterozygote parent, resulting in A blood type. Therefore, the probability of the child having A blood type is 50%. Choice A (25%) is incorrect because it does not consider the possibility of the child inheriting the A allele from the A heterozygote parent. Choice C (75%) and choice D (100%) are incorrect as they overestimate the probability by not accounting for the presence of the O allele in the O parent, which would result in the child having O blood type.

Correct Answer: D

Rationale: The correct answer is D because organisms maintain homeostasis by using free energy and matter to counteract entropy. This is achieved through various biochemical processes that regulate internal conditions within a narrow range to ensure stability. By utilizing energy and matter efficiently, organisms can balance their internal environment despite external fluctuations. Choice A is incorrect because increasing body temperature, blood pH, and fluid balance do not necessarily maintain homeostasis but rather reflect changes in the internal environment. Choice B is incorrect as absorbing energy to increase entropy would disrupt homeostasis rather than maintain it. Choice C is incorrect because maintaining the order of the external environment is not directly related to the internal balance required for homeostasis.

Correct Answer: C

Rationale: The correct answer is C (3). In a typical sensory pathway, there are three neurons involved: the primary sensory neuron, secondary sensory neuron, and tertiary sensory neuron. The primary sensory neuron transmits signals from the sensory receptor to the spinal cord or brainstem. The secondary sensory neuron carries the signal from the spinal cord or brainstem to the thalamus in the brain. Lastly, the tertiary sensory neuron carries the signal from the thalamus to the sensory cortex for processing. Therefore, a sensory pathway typically comprises three neurons to relay sensory information from the periphery to the brain. Choice A (1) is incorrect because sensory pathways involve multiple neurons for signal transmission. Choice B (2) is incorrect as it does not account for the tertiary sensory neuron involved in the pathway. Choice D (4) is incorrect because the typical sensory pathway consists of three neurons, not four.