IB biology Topic 6 SL Human Physiology

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

Tags

NGSS.HS-LS1-2

NGSS.HS-LS1-3

Which statement is true for the antibiotic penicillin

• Watson and Crick developed the usage of penicillin

• pinicillin blocks pathways unique to eukaryotic cells

• Viruses lack metabolism and penicillin has no effect on them

• Florey and Chain sequenced the genome of Penicilium notatum

How can knowledge of the pinneal gland function be applied

• To restore sleep by the use of melatonin

• To trigger ovulation during an IVF treatment

• To reduce sperm production in male contraception

• To regulate blood sugar in type I dibetes

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.

What is the purpose of pulmonary surfactant?

• Promotes capillary growth

• Decreases surface tension

• Adheres alvioli and capillaries

• Stretches the inside surface of the alveoli

• A

• B

• C

• D