Biopsychology: Circadian Rhythm 2024 - 2025

Question 1

Key Term Focus

What two things are biological rhythms controlled by?

These are essential key terms

Answer 1

• Endogenous pacemakers
• Exogenous zeitgebers

These are essential key terms

Question 2

Key Term Focus

What is meant by an endogenous pacemaker?

Answer 2

Internal body clock

Question 3

Key Term Focus

What is meant by exogenous zeitgebers?

Answer 3

External factors in the environment

Question 4

Key Term Focus

What is the difference between an endogenous pacemaker and an exogenous zeitgeber?

Answer 4

• Endogenous pacemaker = internal body clock

WHEREAS

• Exogenous zeitgeber = external factor in environment

Question 5

Key Term Focus

What is a circadian rhythm?

Answer 5

A cycle that lasts for 24 hours

Question 6

AO1 Focus

What is an example of a circadian rhythm?

Answer 6

The sleep wake cycle

Question 7

AO1 Focus

What is an example of a cycle that lasts for 24 hours?

Answer 7

The sleep wake cycle

Question 8

AO1 Focus

What is the main endogenous pacemaker involved in the sleep wake cycle?

Answer 8

Suprachiasatic Nucleus
(SCN)

Question 9

AO1 Focus

What is the main biological structure involved in maintaining the sleep wake cycle?

Answer 9

Suprachiasmatic Nucleus
(SCN)

Question 10

AO1 Focus

What is the main exogenous zeitgeber involved in influencing our sleep wake cycle?

Answer 10

Light

Question 11

AO1 Focus

What is the main external factor which influences our sleep wake cycle?

Answer 11

Light

Question 12

AO1 Focus

Which gland is stimulated to release melotonin?

Remember the endocrine system

Answer 12

Pineal gland

Question 13

AO1 Focus

What causes the pineal gland to become stimulated?

Answer 13

Less light is received by the retina

Remember melotonin promotes sleep - we get ‘sleepy’ when it’s dark = less light

Question 14

AO1 Focus

What happens when our retina’s detect light again after sleeping?

Answer 14

Suprachiasmatic nucleus is reset

Question 15

AO1 Focus

How does the SCN ‘resetting’ affect the pineal gland?

Answer 15

Inhibits (stops) release of melotonin

Question 16

AO2 Focus

Name 3 negative consequences of our sleep wake cycle being disrupted

Answer 16

• Difficulty in sleeping
• Decreased attention
• Digestive problems
• Tiredness and poorer reasoning skils
• Increased anxiety and irritability

Realistically, you will only need to know 2-3 of these for the exam

Question 17

AO2 Focus

Provide two examples of how our sleep wake cycle can become disrupted

Answer 17

• Jet lag
• Night shift work

Question 18

AO2 Focus

Give 3 examples of how we could maintain our sleep wake cycle?

Answer 18

• Keep to local times for eating
• Keep to local times for sleeping
• Being social and active
• Using black out curtains
• Not using phones late at night

Again, realistically for the exam you would only need to know 2-3 of these

Question 19

AO3 Focus

What was DeCoursey’s procedure?

This will form the first E of your PEEL

Answer 19

Destroyed te SCN in the brains of 30 chipmunks who were then returned to their natural habitat and observed

This will form the first E of your PEEL

Question 20

AO3 Focus

What was DeCoursey’s finding?

This will form the second E of your PEEL

Answer 20

A significant portion of the chipmunks had been killed by predators.

This will form the second E of your PEEL

Question 21

AO3 Focus

What does DeCoursey’s research show?

This will form part of your Link in your PEEL

Answer 21

That endogenous pacemakers are important in maintaining circadian rhythms

This will form part of your Link in your PEEL

Question 23

DISCUSSION Focus

How can DeCoursey’s research be criticised?

This can be used as a follow up PEEL

Answer 23

Animal bias

This can be used as a follow up PEEL

Question 24

DISCUSSION Focus

Why is DeCoursey’s research unable to be generlaised to females?

This can be used as a follow up PEEL

Answer 24

Humans may have a more complex interaction between endogenous pacemakers and exogenous zeitgebers

This can be used as a follow up PEEL

Question 25

# **AO3** Focus What was Siffre's procedure? ## Footnote *This will be your first **E** of your P**E**EL*

Answer 25

He lived in a cave isolated from all exogenous zeitgebers for 6 months ## Footnote *This will be your first **E** of your P**E**EL*

Question 26

# **AO3** Focus What did Siffre find within a few days of his study? ## Footnote *This will be your second **E** of your PE**E**L*

Answer 26

He developed a consistent 25-hour cycle and continued to fall asleep **and** wake up on a regular basis ## Footnote *This will be your second **E** of your PE**E**L*

Question 27

# **AO3** Focus What does Siffre's research **show** ## Footnote *This will be part of the **L**ink of your PEE**L**

Answer 27

The sleep wake cycle is mostly controlled by endogenous pacements ## Footnote *This will be part of the **L**ink of your PEE**L**

Question 28

# **DISCUSSION** Focus How can Siffre's research can be criticised? ## Footnote *This can be used as a follow up PEEL*

Answer 28

Lacking ecological validity ## Footnote *This can be used as a follow up PEEL*