Human physiology worksheet with answers

Most homeostatic control systems in the body work by:

1. APositive feedback
2. BNegative feedback
3. CFeed-forward only
4. DRandom variation

Which enzyme begins protein digestion in the stomach?

1. ALactase
2. BAmylase
3. CPepsin
4. DLipase

Which mineral is an essential part of haemoglobin?

1. AIron
2. BCalcium
3. CZinc
4. DIodine

Which protein forms the mesh that stabilises a blood clot?

1. AThrombin
2. BCollagen
3. CFibrin
4. DAlbumin

Which ABO blood group has both anti-A and anti-B antibodies in the plasma?

1. AGroup B
2. BGroup A
3. CGroup AB
4. DGroup O

Why is the oxygen–haemoglobin dissociation curve S-shaped?

1. ABinding of one oxygen makes the next bind more easily
2. BHaemoglobin can bind only one oxygen molecule
3. CRed cells change size as they take up oxygen
4. DOxygen dissolves better in plasma at high partial pressure

A healthy person stands up quickly after lying down. Which reflex response prevents fainting?

1. AThe Bainbridge reflex lowers heart rate
2. BADH release immediately doubles blood volume
3. CThe chemoreceptor reflex raises breathing rate and arterial oxygen levels
4. DThe baroreceptor reflex raises heart rate and vasoconstriction

Why is severe hyperkalaemia dangerous for the heart?

1. AIt depolarises cardiac cells, inactivating sodium channels and causing arrhythmias
2. BIt hyperpolarises cardiac cells, so they can never fire
3. CIt speeds up the SA node until tachycardia causes fainting
4. DIt blocks the binding of calcium to troponin