Question

To increase the effectiveness of exchange surfaces lining the lungs and the intestines, evolutionary pressures have? 1) increased the exchange surface area with folds and branches 2) increased the thickness of the membranes in these linings 3) increased the number of cell layers in these linings 4) decreased the metabolic rate of the cells in these linings 5) increased the volume of the cells in these linings

Answer 1

Evolutionary pressures have increased the exchange surface area of tissues lining the lungs and the intestines by forming folds and branches, facilitating efficient gas exchange and nutrient absorption.

Step-by-step explanation:

Evolutionary pressures have led to an increase in the exchange surface area of tissues lining the lungs and the intestines to increase their effectiveness. This is achieved through adaptations such as folds and branches in these tissues. For instance, the alveoli in the lungs provide a large surface area for the diffusion of gases, which is critical for effective gas exchange in the respiratory system. Similarly, the intestines have fingerlike projections called villi that increase the surface area for absorbing nutrients. A greater surface area facilitates quicker diffusion rates, which is essential for meeting the metabolic demands of the body.

In contrast, increasing the thickness of the membranes or the number of cell layers would actually impede diffusion, making it less efficient. Therefore, among the options provided, the strategy that evolutionary pressures have favored to increase the effectiveness of exchange surfaces is to increase the exchange surface area with folds and branches (option 1).

Answer 2

Evolutionary pressures have increased the exchange surface area of exchange surfaces such as the lungs and intestines with folds and branches to enhance the efficiency of gas exchange and nutrient absorption. A thin respiratory membrane facilitates rapid diffusion, which is critical for efficient gas exchange.

Step-by-step explanation:

To increase the effectiveness of exchange surfaces lining the lungs and the intestines, evolutionary pressures have increased the exchange surface area with folds and branches. This adaptation allows for a greater area over which diffusion can occur, enhancing the efficiency of gas exchange in the lungs and nutrient absorption in the intestines. The increase in surface area through structures like alveoli in the lungs and villi and microvilli in the intestines maximizes this exchange.

Additionally, the respiratory membrane in the alveoli is designed to be thin for efficient gas exchange. This thin barrier between the air and the blood in the capillaries allows for the rapid diffusion of oxygen into the blood and carbon dioxide out of the blood. The thinness of this membrane is crucial; a thicker membrane would reduce the rate of diffusion and be counterproductive to efficient gas exchange.

In the evolutionary process, larger and more complex organisms have developed more specialized structures for these processes, such as a highly permeable respiratory membrane and extensive capillary networks, to suit their increased metabolic needs. These evolutionary trends highlight the importance of a large surface area and minimal barrier thickness for the effective diffusion of gases and nutrients.