Edexcel AS Biology 3

Welcome to your Edexcel AS Biology 3

What is the advantage of a respiratory surface being moistened by mucus?

Which of the following is an adaptation of a respiratory surface for efficient gas exchange?

Which of the following is not a function of the lymphatic system?

The amount of air which passes in or out of the lungs during each cycle of quiet breathing.

The _______ has the thickest wall for pumping blood to the _______.

Singer and Nicolson's hypothesis for membrane structure.

Vessels carrying blood away from the heart.

How does the oxygen move from the lungs into the blood stream?

Select the correct statement/s from the following.
a) Human heart is a hollow muscular organ
b) It is a major component of human circulatory system.
c) It is about the size of it's owner's fist.
d) It consists of 2 layers.

Which is not a main component of cigarette smoke?

Select the incorrect statement regarding the system of trachea in insects.

Which of the following statement is correct regarding the location of human heart?

What is the function of pericardial fluid?

What are the 3 layers of a heart?
a) Endocardium
b) Epicardium
c) Pericardium
d) Myocardium

The function of lymph nodes.

The body structure which protects the lungs from physical harm.

Which layer of the heart secretes the pericardial fluid?

Select the correct sequence of steps regarding inspiration.
a) Air pressure in the lungs decreases.
b) Air flows into the lungs.
c) Volume of the lungs increases.
d) Diaphragm muscles contract.

From which chamber does the freshly oxygenated blood enter the heart?

Select the correct sequence of steps which shows the movement of oxygen through an insect.
a) Spiracle closes.
b) Oxygen is delivered directly to respiring tissues.
c) Oxygen diffuses through the trachea into the tracheoles.
d) Oxygen enters the insect through spiracles and into the trachea.