Question

1) A specialized function shared by the many cells lining the lungs and the lumen of the gut isA) decreased oxygen demand due to the lack of oxygen in foods.B) increased exchange surface provided by their membranes.C) greater numbers of cell organelles contained within their cytoplasm.D) greater protection due to increased cellular mass.E) lowered basal metabolic rate due to cooperation between cells

Answer 1

Answer:

B) increased exchange surface provided by their membranes.

Explanation:

The intestine that characterizes by being folded, and by having its walls covered by villi that project into the lumen. They are more concentrated in the first portion of the intestine, decreasing to the final region of the organ.  They are involved in nutrients absorption by increasing the absorption area.

Nutrients are absorbed by primary cells and transported to the bloodstream.  Mucus is secreted to protect the epithelium during digestion. Villi also transport water from the blood to the intestinal tract, which helps in food decomposition.

Besides the absorption function, the intestine characterizes by doing the peristaltic movement, secretion through special glandules, digestive function, absorptive functions, secretion functions, and endocrine functions.

Animals must have a respiratory membrane to make gas interchange. This surface must be humid, thin, and revested by a simple plane epithelium, plenty of vessels. The membrane must be permeable and exposed for gases to circulate. This membrane might be on the body surface or in specific respiratory organs, such as lugs. The gas exchange occurs by simple diffusion. Oxygen tends to diffuse to the interior of the organisms, while carbon dioxide tends to get out of it.

Answer 2

Answer:

B) increased exchange surface provided by their membranes

Explanation:

Alveoli are tiny air sacs that are responsible for exchanging oxygen (O2) and carbon dioxide (CO2) in the lungs. Alveoli have elastic fibers in order to expand and recoil depending on the volume of air breathed in. The alveolar epithelial cells (pneumocytes) may adopt a shape that serves to increase the surface area of gas exchange. On the other hand, intestinal epithelial cells have microvilli, which are microscopic projections in the plasma membrane. Microvilli serve to increase the cell's surface area, thereby facilitating the absorption of nutrients and water.