Practise IB Biology SL C3.1 by tracing reflex arcs, interpreting brain and organ-coordination evidence, and explaining hormonal and feedback control in the body.
The diagram shows a biofilm that has formed on a tooth.
Using the diagram, explain the concept of emergent properties of biofilms.
Why do multicellular organisms have emergent properties?
They have more genes than unicellular organisms.
Properties of unicellular organisms are enhanced by having many cells.
All of their genes are expressed whereas unicellular organisms express only some.
They show properties that can only result from the interaction of many cells.
Draw a labelled diagram showing the interconnections between the liver, gall bladder, pancreas and small intestine.
The fMRI scan shows a human brain.
On the diagram, label the cerebellum.
The image shows a castor bean tick (Ixodes ricinus) which is commonly found in woodlands or forest areas. This tick can carry bacteria that cause Lyme disease in humans.
Some symptoms of Lyme disease are caused by damage to the central nervous system (CNS). State both parts of the CNS.
1.
2.
Between which structures do sensory neurons carry nerve impulses?
From effectors to the central nervous system (CNS)
From effectors to receptors
From receptors to effectors
From receptors to the central nervous system (CNS)
Where do motor neurons conduct impulses from and to?
From effectors to the central nervous system.
From receptors to the central nervous system.
From neurons to other neurons.
From the central nervous system to effectors.
Draw a labelled diagram of a reflex arc for a pain withdrawal reflex.
Which hormone regulates the hours of sleep and wakefulness?
Thyroxine
Insulin
Leptin
Melatonin
This micrograph shows a transverse section of an artery.
x100
State one function of epinephrine in the human body.
The graph below shows the levels of hormones during the menstrual cycle.
Outline the roles of FSH in the menstrual cycle.
FSH is secreted by the pituitary gland. During pregnancy, FSH secretion is inhibited. Suggest how FSH secretion could be inhibited during pregnancy.
The diagram shows a cross section through an artery and a vein.
Outline two ways in which the human body can increase the heart rate during exercise.
The fMRI scan shows a human brain.
Explain control of breathing rate by the structure labelled X.
What describes the control mechanisms for peristalsis that ensure coordinated passage of material through the digestive system?
Voluntary control by the central nervous system
Involuntary control by the enteric nervous system
Involuntary control by the central nervous system
Voluntary control by the enteric nervous system