Option Questions

Question 1

Using the evidence provided by the data evaluate the hypothesis that the mean rate of food collection increases during the twelve days after the start of foraging on Day 1

Answer 1

• General increase in food collection over 12-day period.
• Large increase between days 1-2, 6-7 and 10-11.
• Most food collected was on day 7
• Declines between 3-5, 8-10 and a large decrease from day 7-8

Question 2

Suggest reasons for the day to day rises and falls in the mean rate of food collection.

Answer 2

• Variations in temperature and/or wind speed

- Flowers produce more nectar in some days than others.

Question 3

Explain how sound is perceived in the ear.

Answer 3

• Sound waves in air cause ear drum to vibrate
• Vibrations are amplified by middle ear bones
• Causes oval window in cochlea to vibrate
• This stimulates cilia hair cells in cochlea
• Cilia hair cells convert vibrations into nerve impulses that are then passed to the brain via optic nerve.

Question 4

State two differences in the way rod and come cells function.

Answer 4

Rod
Function well in dim light
Not responsible for colour vision
Poor visual acuity

Cone
Function well in bright light
Responsible for colour vision
Good visual acuity

Question 5

Explain the pupil reflex in bright light.

Answer 5

• Light detected by cones and rods in retina
• Sensory impulses sent to brain along optic nerve
• Medulla oblongata processes impulses
• Motor impulses sent to circular muscles of iris which constrict and so pupil constricts.

Question 6

Outline the development of birdsong.

Answer 6

• Development of bird song has both innate and learned components
• When birds hatch, they may possess a basic song (crude template) that is species-specific
• After hatching, young birds hear songs from adults of their species and modify their crude template to mimic adult members.
• Song does not develop properly if young bird doesn’t hear other members of species sing
• Young birds practise what they have heard, which improves song to form mature song.

Question 7

Calculate how much time it took the ant to find the food after leaving the nest, giving the units.

Answer 7

350 seconds

Question 8

Estimate how far the ant travelled to the nest after finding the food, giving the units.

Answer 8

50cm

Question 9

Compare the ant’s journey from the nest to the food with the return journey to the nest.

Answer 9

Ant travelled FURTHER and for a longer period of TIME from nest to food than from food to nest.

Question 10

Suggest how the ant knew the direction to return to the nest after finding the food.

Answer 10

Memorised direction

Question 11

Suggest how the other ants in the colony were able to quickly find the same source of food.

Answer 11

Ant communicated with other ants using touch or smell for example.

Question 12

State one advantage to an insect of living in a colony

Answer 12

Division of labour due to large number of insects.

Question 13

Label the bipolar neuron on the diagram

Answer 13

(Middle area of image)

Question 14

Using an arrow, annotate the diagram to show direction in which light moves

Answer 14

|
|
|

(Up)

Question 15

Outline the role of the following structures in perceiving sound.

(I) Bones of the middle ear

(II) Hair cells of cochlea

Answer 15

(I) Amplify sound waves

(II) Convert sound waves to nerve impulses

Question 16

Distinguish between innate behaviour and learned behaviour using birdsong in young birds as an example.

Answer 16

• Innate behaviour present at birth, whilst learned behaviour occurs after birth through experiences.
• Young birds born with crude template of species-specific song (innate)
• Birds refine crude template from listening to adult members of species (learned)

Question 17

Discuss how experiments can be carried out to identify specific functions of parts of the brain.

Answer 17

• Observe abnormal behaviour from patients with a lesion to specific part of brain, which allows links to be made between part of brain injured and abnormal behaviour.
  E.g. Damage to occipital lobes affects patients’s vision
• Neuroimaging tools like fMRI measure blood flow in parts of brain during certain activities, meaning that patients do not have to be injured (can be healthy).
• Experiments on animals are unethical and almost never carried out on humans (which is also unethical). What applies to animals may not apply to humans… And ethical violations.

Question 18

State the difference in mean rate of food collection on Day 7 compared with Day 6, giving the units.

Answer 18

0.16 mgmin(-1)

Question 19

Identify the season and light conditions which result in the strongest northerly direction flown by the robins.

Answer 19

Season: Spring

Light conditions: Green light

Question 20

Distinguish between the effect of red light and green light on the behaviour of the robins in spring and autumn.

Answer 20

In green light, birds migrate north in spring but south in autumn; whereas in red light, birds migrate west in both spring and autumn.

Question 21

Based on the results of these experiments, suggest one possible conclusion that could be drawn regarding the effect of red light on the behaviour of robins.

Answer 21

Red light has almost same effect as total darkness.

Question 22

Using the data in the diagram, deduce with a reason, whether European robins migrate during the daytime or at night.

Answer 22

Daytime, as wrong orientation in darkness.

Question 23

Scientists anesthetized the beaks of some robins in order to deactivate the magnetoreceptors. Predict how this would affect their orientation in red light.

Answer 23

No effect, orientation could actually become even more random.

Question 24

Outline how the pupil reflex can be used to indicate brain death.

Answer 24

Pupil normally contracts when light is shone on it. If pupil does not contract, then it suggests a lack of motor response and hence, no brain processing taking place.

Question 25

Discuss the evolution of altruistic behaviour in animals other than humans.

Answer 25

Altruistic behaviour benefits other individuals and may be harmful to self. This decreases survival of a species but not individuals. Natural selection works at level of gene pools and so it would be expected that natural selection would work against behaviour that reduces chance of survival. Uniquely, vampire bats show altruistic behaviour towards unrelated individuals by sharing regurgitated blood with another colony member who hasn't been fed. It is difficult to explain this behaviour but it is likely because vampire bats benefit as a colony from this.

Question 26

Calculate the decrease in mass of food foraged by fed sand gobies when a predator was introduced, giving the units.

Answer 26

2.6 miligrams

Question 27

Compare the effect that starvation had on both species of goby when no predator was present.

Answer 27

Both foraged more after starvation; black goby increased amount of food foraged more than sand goby.

Question 28

Describe the effect the predator had on the foraging of the gobies.

Answer 28

Predator present causes both species to forage for less food; fed black gobies showed little change in foraging with predator present.

Question 29

Suggest a reason for the effect of the predator.

Answer 29

Gobbies may hide rather than forage when predator present.

Question 30

The diagram shows the structure of the human ear. Label structures I and II.

Answer 30

I: Pinna II: Ear drum

Question 31

Outline how sounds are perceived in the cochlea, including the name of the cell type involved.

Answer 31

Cilia hair cells vibrate with cochlear fluid movement to convert sound waves into nerve impulses.

Question 32

Outline how contralateral processing of visual stimuli occurs in the human eye.

Answer 32

Optic nerves from right eye and left eye meet at chiasma; right brain hemisphere processes information from left visual field from both eyes and vice versa. This allows the brain to perceive depth and size.

Question 33

Identify a function of the parts of the brain by using numerals II to V to complete the chart. Hypothalamus has been completed for you.

Answer 33

Hypothalamus Homeostasis Medulla Oblongata Controls Breathing Cerebellum Coordinates Balance Pituitary Gland Secretes hormones regulating body functions Cerebral Hemispheres Memory Centre

Question 34

Explain the effects of cocaine on the brain.

Answer 34

Cocaine is an excitatory drug that affects synapses that use dopamine as a neurotransmitter. Dopamine affects reward and pleasure pathways in brain. Dopamine molecules are released into synapse and they attach to receptors of post-synaptic membrane. Dopamine is then taken up again by pre-synaptic membrane. Cocaine prevents re-absorption of dopamine by pre-synaptic neuron and causes dopamine to build up un synaptic cleft and so it continues to stimulate post-synaptic neuron, meaning that pleasure effects continue.

Question 35

Identify which stage of cocaine use shows the least percentage difference between identical twins and non-identical twins.

Answer 35

Occasional

Question 36

Compare the results for identical twins and non-identical twins.

Answer 36

Both show lower %'s going from occasional to abuse to dependence; % is higher at every stage for identical twins; non-identical twins % drops to 0 for dependence, but identical twins doesn't.

Question 37

Analyse the data to find whether it supports the hypothesis that genetic factors cause some people to have a much higher chance of cocaine dependence than others.

Answer 37

Supports: Identical twins more likely to behave the same way for abuse and dependence than non-identical twins. Doesn't Support: Environment is major factor for trying cocaine; not enough data for valid statistical analysis either.

Question 38

State the diagnostic tool used for functional analysis in the images.

Answer 38

fMRI

Question 39

Using the table below, distinguish between rod cells and cone cells. Rod cells Cone cells Characteristic Location Light intensity detected Connection to optic nerve

Answer 39

Characteristic Rod cells Cone cells Location Retina Fovea Light intensity detected Dim Bright Connection to optic nerve Group of rod cells Single cell to single fibre to single fibre

Question 40

Outline the challenges in controlling experiments involving human behaviour.

Answer 40

Variations between humans Ethical and legal considerations

Question 41

Explain what is meant by exaggerated traits and how they may develop in males of a species.

Answer 41

Exaggerated traits play a major role in mate selection; but can be a hindrance to survival. Male birds of paradise have courtship rituals that are becoming more and more flamboyant, along with exaggerated physical features and bright colours to attract females. Development of these traits represents expenditure of time and energy, but also reproductive fitness; and so is more likely to mate and produce offspring. Traits are also genetic and so passed on to offspring.

Question 42

State the lowest head circumference measured in newborn babies born to high cocaine users, giving the units.

Answer 42

31 cm

Question 43

State the relationship between birth weight and head circumference in newborn babies whose mothers did not use cocaine.

Answer 43

Babies with higher birth weight have larger head circumference.

Question 44

Using the data in the graph, describe the relationship between cocaine exposure and head circumference in newborn babies.

Answer 44

Head circumference decreases in babies exposed to high levels of cocaine; Smallest head circumference from high cocaine group and largest head circumference from no cocaine group.

Question 45

Deduce the effect of cocaine use on the head circumference of babies with a birth weight below 3.5 kg.

Answer 45

It is likely that head circumference will be smaller; but there is no proof that there is a cause and effect, only that there is a correlation, making predictions.

Question 46

Distinguish between innate and learned behaviour.

Answer 46

Innate behaviour is independent of experience whilst learned behaviour is influenced by experience.

Question 47

State the name of the part of the brain that coordinates balance.

Answer 47

Cerebellum

Question 48

Label the diagram of the ear.

Answer 48

I: Eardrum II: Cochlea III: Auditory Nerve IV: Semicircular Canals

Question 49

Compare the effects of the sympathetic and parasympathetic nervous systems with reference to examples.

Answer 49

``` Sympathetic: Secretes adrenaline Accelerates heart rate Causes pupil dilation Dilates bronchi ``` ``` Parasympathetic: Secretes acetylcholine Slows down heart rate Causes pupil constriction Constricts bronchi ```