Correct Answer: A

Rationale: The correct answer is A: Lateral. Lateral refers to a position farther away from the midline of the body. In the example provided, the little toe is indeed lateral to the big toe on the same foot. This is in contrast to 'medial,' which means closer to the midline. 'Proximal' refers to a position closer to the point of attachment or the trunk of the body, while 'distal' refers to a position farther from the point of attachment or the trunk of the body.

Correct Answer: B

Rationale: A gene is a portion of DNA that contains the instructions for a specific trait. Genotype refers to the genetic makeup of an organism, encompassing all its genes. Phenotype, on the other hand, is the observable physical manifestation resulting from the interaction between an organism's genotype and environmental factors. Choice A is incorrect because genes do not consist of amino acids directly; they are sequences of nucleotides. Choice C is incorrect as genes do not determine traits directly but provide the instructions for proteins that may influence traits. Choice D is incorrect as genes are not lipids, and lipids do not determine traits; they are a type of biomolecule with different functions.

Correct Answer: B

Rationale: The doctor has observed the process of ossification. Ossification is the natural process where cartilage in the body is replaced by bone. This process takes place during fetal development, growth, and bone fracture healing. Ossification involves the formation of bone tissue by depositing minerals like calcium and phosphorus within the cartilage matrix, leading to the development of a bone structure. Choice A, mineralization, refers to the process of forming mineral deposits in tissues, but it does not involve the replacement of cartilage by bone. Choice C, osteoporosis, is a condition characterized by bone density loss and increased fragility, not the natural process of cartilage replacement by bone. Choice D, calcification, is the process of deposition of calcium salts in various tissues, but it does not specifically involve the replacement of cartilage by bone as in ossification.

Correct Answer: A

Rationale: The correct answer is A: Negative feedback loop. Negative feedback loops work to inhibit the stimulus or reduce the deviation from a set point, maintaining homeostasis by counteracting any changes from the norm. In this case, the negative feedback loop acts to minimize any deviation from the body's internal balance, ensuring stability and optimal functioning. Choice B, a positive feedback loop, amplifies the stimulus or deviation, moving systems away from homeostasis. Choice C, an inhibitory feedback loop, is not a commonly recognized term in the context of feedback mechanisms. Choice D, a stimulating feedback loop, is not a standard term and does not accurately describe a feedback loop's role in maintaining homeostasis.

Correct Answer: C

Rationale: In this scenario, where a child complains of heavy breathing even when relaxing and has no history of respiratory problems, the most likely issue is hyperventilation. Hyperventilation is an abnormal breathing pattern where a person breathes in excess of the body's requirements. It can be triggered by stress, anxiety, panic attacks, or lower-than-normal carbon dioxide levels in the blood. Unlike asthma, a blood clot, or exercising too hard, hyperventilation fits the symptoms described and is more common in individuals without a history of respiratory problems.