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A 65-Year-Old Man with a History of Hypertension, Type 2

question 47

Multiple Choice

A 65-year-old man with a history of hypertension, type 2 diabetes mellitus, and tobacco smoking comes to the office reporting mild back pain. Abdominal examination reveals a bruit, but no pulsatile mass is palpated. Femoral and pedal pulses are symmetric. The patient is sent for ultrasound and is found to have a large infrarenal abdominal aortic aneurysm. Open aneurysm repair is performed. During the procedure, the inferior mesenteric artery is ligated, the diseased portion of the aorta is dissected, and a graft is placed from below the renal arteries to the bifurcation of the aorta. Collateral circulation from which of the following vessels is most likely responsible for preventing ischemia of the descending colon?

Explain the ecological concepts of bottom-up and top-down controls and their effects on energy flow and ecosystem dynamics.

Assess the influence of trophic interactions and structures on ecosystem functions, including energy transfer and biomass distribution.

Understand the concept of trophic efficiency and its variation across different ecosystems.

Recognize the ecological impacts of human activities such as agriculture and urban development on freshwater and marine ecosystems.

Definitions:

Meiosis

A form of cell division that reduces the number of chromosomes by half, creating four haploid cells, each genetically distinct from the parent and from each other.

Reproduction

The natural method through which offspring are generated from their progenitors.

Natural Selection

The process by which organisms better adapted to their environment tend to survive and produce more offspring, a fundamental concept in evolutionary biology.

Fecundity

The potential reproductive capacity of an individual or population, often measured by the number of offspring produced.