ATI TEAS 7 science review

Correct Answer: B

Rationale: Serotonin is a neurotransmitter that is associated with regulating mood, sleep, and memory. It plays a crucial role in maintaining emotional balance and is often a target in treating mood disorders like depression and anxiety. Serotonin also helps regulate sleep patterns and is connected to memory function. Dopamine (choice A) is more commonly linked to reward, motivation, and movement. Acetylcholine (choice C) is involved in muscle control and memory. Glutamate (choice D) is a major excitatory neurotransmitter in the brain but is not primarily associated with mood, sleep, and memory.

Correct Answer: A

Rationale: The Pauli exclusion principle states that no two electrons in an atom can have the same set of quantum numbers. This principle directly influences the structure of the atom by defining the maximum number of electrons allowed in each energy level. As a result, it helps determine the electron configuration and the arrangement of electrons in different orbitals within an atom. Choices B, C, and D are incorrect as they do not directly relate to the Pauli exclusion principle's specific impact on the electron distribution within an atom.

Correct Answer: D

Rationale: - Homozygous recessive genotype refers to an individual having two identical recessive alleles for a particular gene (e.g., rr for a trait where r represents the recessive allele). - Homozygous dominant genotype refers to an individual having two identical dominant alleles for a particular gene (e.g., RR for a trait where R represents the dominant allele). - The difference between the two genotypes lies in the specific alleles present in each case, with homozygous recessive having two recessive alleles and homozygous dominant having two dominant alleles. - This genetic difference results in different phenotypes being expressed, as the dominant allele typically masks the expression of the recessive allele in heterozygous individuals.

Correct Answer: C

Rationale: A) Binomial nomenclature is a system used to give each organism a two-part scientific name (genus and species) but does not help in identifying or classifying organisms based on shared characteristics. B) Cladistics is a method of classification based on evolutionary relationships and shared characteristics, but it is not a tool used for identifying organisms. C) A dichotomous key is a tool that helps scientists identify and classify organisms based on their shared characteristics by presenting a series of choices leading the user to the correct identification. D) Domain-based classification is a system of grouping organisms into three domains (Bacteria, Archaea, Eukarya) based on molecular and genetic similarities, but it is not a tool used for identifying organisms based on shared characteristics.

Correct Answer: B

Rationale: Fusion is the process by which lighter nuclei combine to form heavier nuclei, releasing a large amount of energy in the process. This process is the source of energy in stars, including our Sun. Fission, the process of splitting heavier nuclei into lighter nuclei, is not correct. Radioactivity involves the emission of particles or radiation from the nucleus of an unstable atom, which is different from fusion. A chain reaction is a self-sustaining reaction where the products of one reaction cause further reactions, which is unrelated to fusion.