6.1.1

Explain why digestion of large food molecules is essential.

3

Experiment using starch, glucose & visking tubing to illustrate that only small molecules pass through the intestinal wall

Explain what happened - using a labelled diagram of small intestine to show the macromolecules, the enzymes and the products to explain digestions and hydrolysis...(revision of topic3)

6.1.2

Explain the need for enzymes in digestion.

3

increasing the rate of digestion at body temperature should be emphasized.

6.1.3

State the source, substrate, products and optimum pH conditions for one amylase, one protease and one lipase.

1

Complete the table in the revision booklet.

Data logging with pH sensors and lipase experiment.

Data logging with colorimeters and amylase.

6.1.4

Draw and label a diagram of the digestive system.

1

The diagram worksheet should show the mouth, esophagus, stomach, small intestine, large intestine, anus, liver, pancreas and gall bladder. & the interconnections between these structures.
Use this worksheet

6.1.5

Outline the function of the stomach, small intestine and large intestine.

2

6.1.6

Distinguish between absorption and assimilation.

2

6.1.7

Explain how the structure of the villus is related to its role in absorption and transport of the products of digestion.

3

6.2.1

Draw and label a diagram of the heart showing the four chambers, associated blood vessels, valves and the route of blood through the heart.

1

Care should be taken to show the relative wall thickness of the four chambers. Neither the coronary vessels nor the conductive system are required.

6.2.2

State that the coronary arteries supply heart muscle with oxygen and nutrients.

1

6.2.3

Explain the action of the heart in terms of collecting blood, pumping blood, and opening and closing of valves.

3

Complete the worksheet to complement the dissection.

Heart beat challenge - can you do a running commentary of this animation?

6.2.4

Outline the control of the heartbeat in terms of myogenic muscle contraction, the role of the pacemaker, nerves, the medulla of the brain and epinephrine (adrenaline).

2

Histology of the heart muscle, names of nerves or transmitter substances are not required.

Aim 7: Simulation and data logging involving heart rate monitors, or data logging involving an EKG sensor to measure electrical signals produced during muscle contractions, can be used. Electrocardiogram

6.2.5

Explain the relationship between the structure and function of arteries, capillaries and veins.

3

6.2.6

State that blood is composed of plasma, erythrocytes, leucocytes (phagocytes and lymphocytes) and platelets.

1

6.2.7

State that the following are transported by the blood: nutrients, oxygen, carbon dioxide, hormones, antibodies, urea and heat.

1

No chemical details are required.

6.3.1

Define pathogen.

1

Pathogen: an organism or virus that causes a disease.

6.3.2

Explain why antibiotics are effective against bacteria but not against viruses.

3

Antibiotics block specific metabolic pathways found in bacteria. Viruses reproduce using the host cell’s metabolic pathways, which are not affected by antibiotics.

Aim 8: The great benefits to people throughout the world in the control of bacterial diseases using antibiotics should be stressed.
Examples of diseases that often proved fatal before the advent of antibiotics could be named.

6.3.3

Outline the role of skin and mucous membranes in defence against pathogens.

2

Transmission of bacteria - examples of pathogens

A diagram of the skin is not required.

Influenza questions

6.3.4

Outline how phagocytic leucocytes ingest pathogens in the blood and in body tissues.

2

Details of the subdivisions and classifications of phagocytes are not required.

6.3.5

Distinguish between antigens and antibodies.

2

6.3.6

Explain antibody production.

3

Many different types of lymphocyte exist. Each type recognizes one specific antigen and responds by dividing to form a clone. This clone then secretes a specific antibody against the antigen. No other details are required.

6.3.7

Outline the effects of HIV on the immune system.

2

The effects of HIV should be limited to a reduction in the number of active lymphocytes and a loss of the ability to produce antibodies.

6.3.8

Discuss the cause, transmission and social implications of AIDS.

3

Aim 8: The social implications of AIDS

TOK: The different methods of transmission of HIV each carry their own risk.

6.4.1

Distinguish between ventilation, gas exchange and cell respiration.

2

6.4.2

Explain the need for a ventilation system.

3

A ventilation system is needed to maintain high concentration gradients in the alveoli.

6.4.3

Describe the features of alveoli that adapt them to gas exchange.

2

This should include a large total surface area, a wall consisting of a single layer of flattened cells, a film of moisture and a dense network of capillaries.

6.4.4

Draw and label a diagram of the ventilation system, including trachea, lungs, bronchi, bronchioles and alveoli.

1

Produce a diagram of the thorax and include the following labels, anntated with their function. Trachea, lungs, bronchi, bronchioles, diaphragm, intercostal muscles, pleural membrane and alveoli

Draw alveoli in an inset diagram at a higher magnification, explaining how their structure improve gaseous exchange.

6.4.5

Explain the mechanism of ventilation of the lungs in terms of volume and pressure changes caused by the internal and external intercostal muscles, the diaphragm and abdominal muscles.

3

Aim 7: Data logging involving spirometers or ventilation rate monitors is possible here.

6.5.1

State that the nervous system consists of the central nervous system (CNS) and peripheral nerves, and is composed of cells called neurons that can carry rapid electrical impulses.

1

No other structural or functional divisions of the nervous system are required.

6.5.2

Draw and label a diagram of the structure of a motor neuron.

1

Include dendrites, cell body with nucleus, axon, myelin sheath, nodes of Ranvier and motor end plates.

6.5.3

State that nerve impulses are conducted from receptors to the CNS by sensory neurons, within the CNS by relay neurons, and from the CNS to effectors by motor neurons.

1

6.5.4

Define resting potential and action potential (depolarization and repolarization).

1

6.5.5

Explain how a nerve impulse passes along a non-myelinated neuron.

3

Follow the animation on this website. Use diagrams to define how the resting potential is maintained, and the process of depolarisation and repolarisation and the return to the resting potential.

Watch this animation then try the questions below it

• Write a definition of the following terms
  Resting Potential
  Action Potential
  Depolarisation
  Repolarisation
  Refractory period
  All or Nothing principal

Include the movement of Na+ and K+ ions to create a resting potential and an action potential.

6.5.6

Explain the principles of synaptic transmission.

3

Watch this animation and answer the questions below it

Include the release, diffusion and binding of the neurotransmitter, initiation of an action potential in the post-synaptic membrane, and subsequent removal of the neurotransmitter.

Aim 7: Data logging can be used to measure changes in conductivity

6.5.7

State that the endocrine system consists of glands that release hormones that are transported in the blood.

1

The nature and action of hormones or direct comparisons between nerve and endocrine systems are not required.

6.5.8

State that homeostasis involves maintaining the internal environment between limits, including blood pH, carbon dioxide concentration, blood glucose concentration, body temperature and water balance.

1

The internal environment consists of blood and tissue fluid.

6.5.9

Explain that homeostasis involves monitoring levels of variables and correcting changes in levels by negative feedback mechanisms.

3

6.5.10

Explain the control of body temperature, including the transfer of heat in blood, and the roles of the hypothalamus, sweat glands, skin arterioles and shivering.

3

Aim 7: Data logging using a surface temperature sensor to investigate the warming by nasal passages could be carried out here.

6.5.11

Explain the control of blood glucose concentration, including the roles of glucagon, insulin and α and β cells in the pancreatic islets.

3

The effects of adrenaline are not required here.

Questions about thermoregulation

Carry out experiments

• to measure perspiration,
• to simulate homeostasis with a bunsen and thermometer,
• test urine for glucose.

Questions on glucose control

Diabetes notes (useful for the Assessed Expt)

Assessed Experiment on Blood Glucose Levels

6.5.12

Distinguish between type I and type II diabetes.

2

Aim 8: Diabetes is having an increasing effect on human societies around the world,

TOK: The causes of the variation in rates of type II diabetes in different human populations could be analysed.

6.6.1

Draw and label diagrams of the adult male and female reproductive systems.

1

The relative positions of the organs is important. Do not include any histological details, but include the bladder and urethra.

6.6.2

Outline the role of hormones in the menstrual cycle, including FSH (follicle stimulating hormone), LH (luteinizing hormone), estrogen and progesterone.

2

6.6.3

Annotate a graph showing hormone levels in the menstrual cycle, illustrating the relationship between changes in hormone levels and ovulation, menstruation and thickening of the endometrium.

2

6.6.4

List three roles of testosterone in males.

1

Limit this to pre-natal development of male genitalia, development of secondary sexual characteristics and maintenance of sex drive.

6.6.5

Outline the process of in vitro fertilization (IVF).

2

6.6.6

Discuss the ethical issues associated with IVF.

3

Aim 8: There is great variation between human societies around the world

TOK: There are potential risks in the drug treatments