Which action will increase the chance of urinary tract infection?

Choice A reason: Autosomal dominant disorders affect both genders equally, as they are not sex-linked. Heterozygous individuals express the disorder, not just males, due to the dominant allele on an autosome. The idea of females being carriers only applies to X-linked recessive disorders, making this choice scientifically inaccurate.

Choice B reason: Autosomal dominant disorders are caused by mutations on autosomes, not the Y chromosome, which is sex-linked and primarily affects males. These disorders do not typically skip generations, as the dominant allele is expressed in every affected individual, making this choice incorrect.

Choice C reason: In autosomal dominant disorders, a single mutated allele is sufficient for expression. An affected parent (heterozygous) has one normal and one mutated allele, leading to a 50% chance of passing the mutated allele to each child, causing the disorder. This genetic inheritance pattern makes this the correct choice.

Choice D reason: In autosomal dominant disorders, there is no "carrier" state as in recessive disorders, because heterozygous individuals express the disorder. The 50% probability applies to inheriting the disorder itself, not a carrier genotype, which is a concept relevant to autosomal recessive disorders, making this choice incorrect.

Choice A reason: Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system, reducing neuronal excitability by opening chloride channels, hyperpolarizing neurons, and preventing action potentials, making this the correct choice.

Choice B reason: Norepinephrine is an excitatory neurotransmitter and hormone, increasing neuronal activity and arousal in the sympathetic nervous system. It does not inhibit neural signaling, making this choice incorrect for an inhibitory neurotransmitter.

Choice C reason: Histamine acts as a neurotransmitter promoting wakefulness and arousal, not inhibition. It stimulates neuronal activity in the brain, unlike inhibitory neurotransmitters that reduce firing, making this choice incorrect for the role.

Choice D reason: Glutamate is the primary excitatory neurotransmitter, promoting neuronal firing by depolarizing neurons via ion channel activation. It does not inhibit neural activity, making this choice incorrect for an inhibitory neurotransmitter.