There are three sources of genetic variation: mutation, gene flow, and sexual reproduction. A mutation is simply a change in the DNA.
The correct answer is "coarctation of the aorta". In coarctation of the aorta, there is an abnormal narrowing of the aorta, most commonly in the abdominal aorta, which compromises blood flow from going into the lower extremities. Patients with coarctation of the aorta most commonly presents with tachypnea as this is a high pressure congenital heart defect which makes breathing harder for the baby; diminished femoral pulses and poor lower body perfusion as the narrowing compromises blood flow. In physical examination, there will be a narrow ankle-brachial index, or the difference between the pulse pressures of the ankle (lower extremity) and the brachium (upper extremity).
<span>Human activities can alter an ecosystem and bring about the extinction of a species. Such activities include any of these except assuring a habitat remains unaltered.
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