Edexcel AS Biology 4

Welcome to your Edexcel AS Biology 4

Tiny vessels that link arteries and veins.

Select the correct sentence regarding smoking.

A fluid secreted by the alveoli.

Lungs are encased in thin membranes called ________.

What is the advantage of a thin wall in a respiratory surface?

Number of openings in the right auricle.

What is the first step of expiration?

When breathing, air is filtered, warmed and moistened in this organ.

Which of the following aids in stretching and recoiling of alveolar walls?

Which of the following is not a component of gastric juice?

Which of the following is not a reason for the evolvement of respiratory surfaces with high AV ratios?

Which of the following is not a characteristic of a double circulation?

The specific site of gas exchange in humans.

Which is not a function performed by the stomach?

An advantage of gas exchange in water over the gas exchange in air.

Select the incorrect statement regarding arteries.

Which of the following is not a function of surfactant?

The mammalian circulatory system is a ___________.

What is the respiratory organ of an earthworm?

Select the incorrect statement regarding COPD.