Nokea
An atom has 5 protons, 5 neutrons, and 6 electrons. What is the electric charge of this atom?
- A. Neutral
- B. Positive
- C. Negative
- D. Undetermined
Correct Answer: C
Rationale: The correct answer is 'Negative.' An atom becomes negatively charged when it has more electrons than protons. In this case, the atom has 6 electrons and 5 protons, resulting in a net negative charge. Choice A 'Neutral' is incorrect because the atom is not balanced in terms of protons and electrons. Choice B 'Positive' is incorrect because having more electrons than protons results in a negative charge. Choice D 'Undetermined' is incorrect, as the charge can be determined based on the relative number of protons and electrons.
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Which blood vessel carries oxygenated blood back to the heart?
- A. Pulmonary vein
- B. Pulmonary artery
- C. Aorta
- D. Superior vena cava
Correct Answer: A
Rationale: The corrected question is asking for a blood vessel that carries oxygenated blood back to the heart. The pulmonary vein is the correct choice as it carries oxygenated blood from the lungs back to the heart during systemic circulation. The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation. The aorta is the main artery that carries oxygenated blood away from the heart to the body. The superior vena cava returns deoxygenated blood from the upper body back to the heart.
Which term describes the allele for green eyes?
- A. Dominant
- B. Recessive
- C. Homozygous
- D. Heterozygous
Correct Answer: B
Rationale: The correct answer is 'B: Recessive.' In genetics, eye color is determined by multiple genes, with green eyes often being associated with a recessive allele. When an individual carries two copies of the recessive allele for green eyes, they will express this eye color. Dominant alleles are expressed over recessive alleles. Homozygous refers to having two identical alleles for a particular gene, and heterozygous refers to having two different alleles. In this context, the allele for green eyes is recessive, meaning it is expressed only when an individual carries two copies of this specific allele. Therefore, 'Recessive' is the most appropriate term to describe the allele for green eyes, making it the correct answer.
Which of the following statements correctly describes the function of a physiological structure?
- A. The trachea connects the throat and the stomach.
- B. The esophagus joins the larynx with the lungs.
- C. The diaphragm controls the height of the thoracic cavity.
- D. The epiglottis covers the trachea during swallowing.
Correct Answer: D
Rationale: The epiglottis is a flap of tissue that covers the trachea during swallowing to prevent food and liquids from entering the airway. This action helps direct food into the esophagus, ensuring proper passage into the digestive system and avoiding potential choking or aspiration into the lungs. Choices A, B, and C are incorrect because the trachea connects the larynx to the bronchi, the esophagus connects the throat to the stomach, and the diaphragm is a muscle that plays a vital role in breathing by separating the thoracic and abdominal cavities, aiding in respiration.
Which of the following characteristics is part of a person's genotype?
- A. Brown eyes that appear hazel in the sunlight
- B. The CFTR gene, which causes cystic fibrosis
- C. Black hair that grows rapidly
- D. Being a fast runner
Correct Answer: B
Rationale: The correct answer is B. A genotype refers to a person's genetic makeup, which includes specific genes like the CFTR gene responsible for cystic fibrosis. Genes are the units of heredity and are part of an individual's genotype, influencing various traits and characteristics. Choice A, brown eyes that appear hazel in the sunlight, refers to a phenotype, which is the observable characteristics resulting from the interaction of genes and the environment. Choice C, black hair that grows rapidly, also describes a phenotype rather than a genotype. Choice D, being a fast runner, is a trait influenced by a combination of genetic and environmental factors, but it does not directly relate to a specific gene in the genotype.
Which structure controls the hormones secreted by the pituitary gland?
- A. Hypothalamus
- B. Adrenal gland
- C. Testes
- D. Pancreas
Correct Answer: A
Rationale: The correct answer is A: Hypothalamus. The hypothalamus controls the release of hormones from the pituitary gland. It acts as a master regulator of the endocrine system by producing releasing and inhibiting hormones that influence the secretion of hormones from the pituitary gland. Choice B, the Adrenal gland, is incorrect because while it plays a role in hormone production, it is not responsible for controlling the pituitary gland's hormones. Choice C, the Testes, and Choice D, the Pancreas, are also incorrect as they are not directly involved in controlling the hormones secreted by the pituitary gland.