IB Biology Topic 6

What happens to starch in the small intestine?

• Endopeptidase, secreted by the liver digests starch to enable absorption by the villi

• Contraction of the intestinal muscles mixes starch with enzymes to accelerate its conversion into amylose

• Glycogen secreted by the pancreas hydrolyses starch into glucose, which is eventually transported to the liver

• Amylase secreted by the pancreas digests starch to enable absorption by the villi

The picture shows the layers of tissues in a transverse section of the human small intestine. Which layer is labelled with the letter X?

• Mucosa

• Circular muscle

• Epithelium

• Longitudinal muscle

Tags

NGSS.HS-LS1-2

Which discovery was an indication that the heart pumps blood to the body through the arteries?

• The amount of blood pumped exceeds that of blood produced

• Blood could easily be pushed up a limb vein, but not down

• The observation that there were pores between the left and right atria

• The heart swelled up when arteries were tied in an animal experiment

Which row shows a valid comparison of arteries and veins?

• A

• C

• B

• D

The diagram shows the pressure changes during a cardiac cycle. Which is an explanation of what is happening?

• During phase I, pressure in the left ventricle decreases while it increases in the aorta during contraction of the left atrium

• In phase II , pressure rises in the aorta because the left ventricle is contracting

• In phase III, pressure decreases in the aorta because the left atrium is relaxing

• In phase III, there is a constant increase of pressure in the aorta as both the left atrium and ventricle are at rest

What is the position of the heart valves when blood pressure is highest in the aorta?

• Atrioventricular valves: open. Semilunar valves: closed.

• Atrioventricular valves: closed. Semilunar valves: open.

• Atrioventricular valves: closed. Semilunar valves: closed.

• Atrioventricular valves: open. Semilunar valves: open.

Which process is occurring in the small intestine?

• A

• B

• C

• D

Tags

NGSS.MS-LS1-7

In which blood vessels connected to the heart does the blood have the lowest carbon dioxide concentration?

• Pulmonary vein

• Vena cava

• Pulmonary artery

• Coronary vein

The picture shows a human heart. Which shows the sequence of blood flow through the heart?

• III ----> IV ----> I

• IV ----> III ----> II

• VII ----> VIII ----> I

• VIII ----> VII ----> VI

Which part of the body secretes amylase, lipase and endopeptidase for use in the digestion of food?

• Mouth

• Pancreas

• Stomach

• Small intestine

Tags

NGSS.MS-LS1-7