Correct Answer: A

Rationale: The basic structure of an atom consists of protons and neutrons located in the nucleus, with electrons orbiting around the nucleus in specific energy levels or shells. Protons carry a positive charge, neutrons carry no charge, and electrons carry a negative charge. This arrangement maintains the overall neutrality of the atom, with the number of protons equaling the number of electrons. Therefore, the correct answer is 'Protons, neutrons, electrons.' Choices B, C, and D are incorrect as they do not accurately represent the fundamental components of an atom. Choice B includes 'ions,' which are charged particles, not fundamental components of an atom. Choice C includes 'ions' and lacks protons. Choice D includes 'ions' and 'molecules,' which are not part of the basic structure of an atom.

Correct Answer: D

Rationale: Human cells typically contain genes that code for proteins necessary for the cell's functions. DNA that codes for proteins the cell doesn't use would be an inefficient use of the cell's resources. Therefore, it is less likely to be found in a human cell's genes. Options A, B, and C are more commonly associated with genes found in human cells. Choice A refers to the genetic information needed for protein synthesis, while choice B involves traits that can be present in the gene pool. Mutated DNA (choice C) can also be found in human cells as a result of genetic alterations. However, DNA that codes for proteins not utilized by the cell would be redundant and not typically retained in the genome.

Correct Answer: A

Rationale: The correct answer is A. The forebrain is primarily responsible for higher cognitive functions such as perception, interpretation, and integration of sensory information, emotional responses, and voluntary movements. Functions like regulating blood pressure and heart rate are mainly controlled by various structures in the brainstem, such as the medulla oblongata and the pons. Choices B, C, and D are all functions associated with the forebrain. Choice B relates to the limbic system, which is part of the forebrain responsible for emotional responses. Choice C corresponds to the occipital lobe in the forebrain, involved in processing visual information. Choice D involves the motor cortex and other areas in the forebrain that coordinate voluntary movements.

Correct Answer: B

Rationale: The correct answer is 'Anabolic reaction.' Anabolic reactions involve the synthesis of larger and more complex molecules from smaller ones, requiring an input of energy, often in the form of ATP. These reactions are essential for processes like growth, repair, and the building of cellular structures. Catabolic reactions, on the other hand, break down larger molecules into smaller ones, releasing energy. Exothermic reactions release heat, while hydrolytic reactions involve the breakdown of molecules with the addition of water. Therefore, choices A, C, and D are incorrect as they do not describe the process of building larger and more complex molecules from smaller ones with the requirement of energy.

Correct Answer: B

Rationale: The correct answer is B: Contraction of the heart. Systole is the phase of the cardiac cycle during which the heart muscle contracts, pumping blood out of the chambers. It is essential for maintaining circulation and delivering oxygen and nutrients to the body's tissues. Diastole (choice C) is the relaxation phase of the heart when the chambers fill with blood. Pulse rate (choice D) is the number of heartbeats per minute, not specifically related to the systole phase. Choice A, 'Relaxation of the heart,' is incorrect because systole refers to the contraction phase of the cardiac cycle, not relaxation.