IBDP Online Test Series By iitianacademy
Comprehensive Test Preparatory package targeted towards IBDP
Question
Honey bees (Apis mellifera) were fed with sucrose solution only or with low doses of ethanol in sucrose solution to examine how a slightly intoxicated state could affect their behaviour. Individual behaviour involves walking and grooming while social behaviour includes contact of antennae between bees to show recognition (antennation) and asking other bees for food when hungry (begging). The graphs show individual and social behaviour changes observed in successive five minute intervals two hours after honey bees were fed sucrose solution either with or without ethanol.
State the percentage of time the honey bees engaged in begging during the first five minute interval.
Bees fed with ethanol: …………………%
Bees fed without ethanol: …………………%
Describe the trends in antennation for honey bees fed with ethanol and without ethanol.
Distinguish between the times spent walking and grooming for honey bees fed with ethanol and without ethanol.
Evaluate the hypothesis that ethanol affects the social behaviour of honey bees.
Answer/Explanation
Markscheme
a. without alcohol (antennation starts at a high level and) decreases with time;
b. with alcohol, the value (starts low and) very slowly increases;
c. the values of both group become very similar with time;
a. (time spent) walking is greater in bees without alcohol (than alcohol);
b. (time spent) grooming is greater with alcohol (than without alcohol);
c. the end point difference is greater in walking;
d. (time spent) walking increases whereas grooming decreases for both groups of bees;
a. (hypothesis supported as) alcohol decreases antennation at the start of the experiment;
b. (hypothesis supported as) alcohol increases begging at the start;
c. begging time is more variable/has less significant differences with alcohol so less clear than in antennation;
d. (hypothesis is supported as) the effect of alcohol on social behaviours becomes less distinguishable over time (with the effect of sucrose);
Question
Moths use a variety of sensory processes (including vision, smell and mechanoreception) to locate nectar on flowers. The ability of the nocturnal tobacco hornworm moth, Manduca sexta, to find nectar using mechanoreceptors was investigated using artifical flowers. Three-day-old moths that had no experience of natural flowers were used in the investigation. The artificial flowers had nectar placed at the centre and were made of either paper (with a rough surface to stimulate mechanoreception) or plastic (to reduce mechanoreception). The time taken for moths to discover the nectar (discovery time) over a series of eight trials is shown for the artificial flower types. Vertical bars show the variation in the data.
Identify the trial for each flower type that shows the greatest variation.
Paper:
Plastic:
Compare the data for plastic and paper flowers.
Outline the evidence from the data that the ability to find nectar using mechanoreceptors is a learned behaviour.
Discuss how learning to find nectar using mechanoreceptors could lead to improved chances of survival and reproduction for the tobacco hornworm moth.
Answer/Explanation
Markscheme
Paper: (trial) 1
Plastic: (trial) 5
Both required for [1].
a. discovery time in paper flowers always shorter than plastic flowers;
b. larger variation in data for plastic flowers;
c. decreasing discovery time (over the eight trials) for the paper flowers only;
d. no trend in discovery time for plastic flowers;
e. from trial four discovery time for paper flowers remains fairly constant/slight variation whereas for plastic flowers discovery time increases;
a. mechanoreceptors are touch receptors;
b. discovery time decreases over the eight trials for paper flowers;
c. showing evidence of learning;
d. plastic flowers discovery times show no evidence of learning;
e. paper flowers have a rough surface so mechanoreceptors are more effective / plastic flowers smooth so do not stimulate mechanoreceptors;
a. improved chances of finding food;
b. advantage in dark/conditions when coloured/scented flowers not available;
c. not completely dependent on light/chemoreceptors to find food;
d. more likely to reproduce and pass gene (for mechanoreceptors) to offspring; advantage over other members of the species through learning;
Question
The diagram above shows the set up similar to that used in Pavlov’s experiments on conditioning in dogs. Describe Pavlov’s experiments on conditioning in dogs.
Salivation is normally a simple reflex. Explain the role of sensory, relay and motor neurons in a simple reflex.
Answer/Explanation
Markscheme
a. smell or sight of food provides the (unconditioned) stimulus at the start of the experiment;
b. salivation at the sight or smell of the food is the (unconditioned) response;
c. bell/other stimulus repeatedly applied just before food;
d. bell/other stimulus provides a (conditioned) stimulus;
e. (conditioned) response is salivation at the bell/other stimulus only;
f. experiment was an example of classical conditioning;
Award [2 max] if the terms stimulus and response are not used.
a. sensory neuron carries signal from sense organ/receptors/nose/eye to CNS;
b. motor neuron carries signal from CNS to effector/muscle/salivary gland;
c. relay neuron carries signal from sensory neuron to motor neuron;
Question
Draw a labelled diagram of a reflex arc for a pain withdrawal reflex.
Distinguish between innate behaviour and learned behaviour.
Answer/Explanation
Markscheme
Award [1] for any one of the following clearly drawn and correctly labelled.
a. spinal cord – showing white and grey matter;
b. spinal nerves – showing dorsal and ventral roots;
c. sensory neuron / receptor;
d. motor neuron / effector;
e. relay neuron;
f. arrows showing path from stimulus/receptor to response/effector;
Question
Scientists investigated if training has an influence on the learning of birdsong. They studied juvenile zebra finches (Taeniopygia guttata) that had never been exposed to adult bird songs. They measured neuron activity in an area of the brain involved with song learning. This was done during their sleep, first for four nights when the birds had not heard any birdsong during the previous day, and then for a series of nights after days when they were exposed to recordings of adult zebra finches’ songs. In the graph below, the mean neuron activity in the period of no exposure to birdsong was used as a baseline and assigned a value of 1. All other measurements of neuron activity are shown relative to this.
State the difference in neuron activity between nights 2 and 7.
Outline the effect of exposure to birdsong on neuron activity.
Suggest one reason for the large error bars on days 14 and 15.
Evaluate the hypothesis that listening to other zebra finches is important to develop singing ability amongst juveniles.
Answer/Explanation
Markscheme
0.8 (Accept answers from 0.75 to 0.85.)
a. increases neuron activity;
b. increase over three days/increase of about 75 %/of 50–100 %;
c. then plateaus/levels off;
d. large variation on days 14 and 15;
a. small sample so one measure can skew the average / higher average value due to only one measurement;
b. different birds respond differently/nothing being learned;
c. change in behaviour due to biotic/abiotic changes;
a. hypothesis seems to be verified since all points after exposure to birdsong are higher;
b. learning phase (supported by changes on days 5–7);
c. experiment shows only one brain area activity / other factors may also be involved;
Question
Define the term reflex.
Draw a labelled diagram of a reflex arc for a pain withdrawal reflex.
Outline Pavlov’s experiments into conditioning in dogs.
Answer/Explanation
Markscheme
rapid and unconscious/automatic response (to a stimulus)
Example of diagram.
sensory neuron shown connecting site of stimulus/receptor to relay neuron;
relay neuron shown in grey matter, connecting sensory neuron to motor neuron;
motor neuron shown connecting relay neuron to effector/muscle / cell body of motor neuron shown in grey matter;
cell body of sensory neuron shown outside spinal cord/in dorsal root;
spinal cord shown with grey and white matter;
unconditioned stimulus is smell/sight of food and unconditioned response is salivation;
conditioned stimulus is sound of a bell and conditioned response is salivation at sound of bell;
bell/other stimulus is repeatedly applied just before food;
after several repeats the response can be seen without the food/when only the bell is rung/other stimulus;
Question
Draw a labelled diagram of a reflex arc for a pain withdrawal reflex.
Answer/Explanation
Markscheme
Diagrams are to include the following structures appropriately drawn and in appropriate relationship to each other.
(pain) receptor indicated at the dendrite end of the sensory neuron;
sensory neuron shown in appropriate abbreviated shape from a (pain) receptor to the central nervous system (CNS) with dendrites and axon;
dorsal root ganglion shown next to the CNS;
relay neuron/interneuron/associative neuron shown in the CNS/spinal cord with dendrites and axon;
motor neuron shown with dendrites and axon from the CNS to an effector;
effector/muscle labelled as a muscle;
white matter shown correctly in the spinal cord;
grey matter shown correctly in the spinal cord;
spinal cord shown connected to the brain and with appropriate position relative to the structures given above;
Award [3 max] for inaccurate diagrams.
N.B. Accept stylized diagrams of neurons.
Question
Define the term reflex in animal behaviour.
Outline the main roles of motor, sensory and relay neurons in a spinal reflex arc.
Answer/Explanation
Markscheme
a rapid and unconscious/automatic response (to a stimulus)
Question
Outline the development of birdsong in young birds.
Answer/Explanation
Markscheme
bird born with innate knowledge of (basic) song;
song birds have sensitive period during which they can learn a song;
must listen to tutor song;
birds are selective in what song they learn / not any song can be learned;
song must match some innate knowledge of song that bird is born with/inherited;
practice singing (subsong) precedes full song;
song, once learned, is rarely modified;
Question
Below is a diagram of a reflex arc for a pain withdrawal reflex.
Define reflex.
Label the parts indicated by the letters I–IV.
I. ……………………………………………………..
II. ……………………………………………………..
III. ……………………………………………………..
IV. ……………………………………………………..
Explain the role of parts I and II in a pain withdrawal reflex.
Answer/Explanation
Markscheme
rapid response that occurs automatically/involuntarily in response to a stimulus
Two correct labels for [1]
I: sensory neuron
II: motor neuron
III: dorsal root (of spinal nerve) NOT dorsal root ganglion
IV: white matter (of spinal cord
receptor cell detects stimulus and converts it to a nerve impulse;
impulse travels along sensory neuron to (dorsal root of) spinal cord;
impulse travels along motor neuron to effector organ;
causes muscle to contract removing contact with painful stimulus;
Need to mention BOTH structures I AND II for 2 marks.
Question
State the type of receptor cells that detect sound.
Outline the role of inheritance and learning in the development of birdsong in young birds.
Answer/Explanation
Markscheme
mechanoreceptor
inheritance plays role as basic song is the same for all members of a species;
birds raised in isolation still sing but song lacks complexity/sounds different from song heard in the wild / more complex songs develop when there is social interaction;
young birds learn details of songs/dialects from fathers/other birds;
(development of birdsong) is a form of motor learning/ability to learn is genetic/inherited;
Question
Distinguish, using examples, between innate behaviour and learned behaviour.
Using two examples, discuss how the process of learning can improve survival.
Answer/Explanation
Markscheme
learned behaviour occurs as a result of experience (while innate is independent of environment);
innate behaviour is controlled by genes/inherited (while learned is not inherited);
correct example of both;
name of animal, how they learn and advantages for survival;
name of another animal, how they learn and advantages for survival;
e.g. grizzly bears by operant conditioning/practise how to catch salmon providing needed food supply;
goslings learn who their mother is/imprinting, avoid predators by staying near mother;
Question
The diagram below shows a reflex arc.
Label I and II.
I. …………………………………………………………
II. …………………………………………………………
Outline how stimuli can be detected by human sensory receptors.
Explain how sound is perceived by the ear.
Answer/Explanation
Markscheme
I: sensory neuron
II: motor neuron
(both needed)
sensory receptors transfer stimulus energy into electrochemical energy;
mechanoreceptors respond to touch/pressure/movement/sound waves;
thermoreceptors respond to temperature changes;
chemoreceptors detect chemicals/molecules;
photoreceptors respond to electromagnetic stimulation/light;
sound waves are (funneled through the ear canal) causing ear drum to vibrate;
vibrations of ear drum cause the bones of the middle ear/ossicles/malleus, incus and stapes/hammer, anvil and stirrup to move;
lever system of middle ear bones increases pressure on the oval window;
vibrations are transmitted from oval window through (fluid-filled) cochlea;
stimulation of hair cells/mechanoreceptors in cochlea;
vibrations are transformed into nerve impulses/action potentials;
impulse sent to brain along auditory nerve;
Question
Distinguish between innate and learned behaviour.
Outline the role of inheritance and learning in the development of birdsong in young birds.
Explain the effects of cocaine on mood and behaviour.
Answer/Explanation
Markscheme
innate behaviour develops independently of the environmental context/genetically
inherited and learned behaviour develops as a result of experience / OWTTE
young birds learn birdsong from parents/other adults;
young birds removed from parents capable of own song;
basic song template may be inherited;
learned birdsong is louder/richer;
(cocaine causes) dopamine build up in synapses / continuous neurotransmitter presence;
increased energy/alertness/feeling of euphoria/pleasure;
user becomes isolated/suspicious/less productive / alienates family and friends;
cocaine addiction/use may lead to crime/robbery to buy cocaine;
Question
Distinguish between innate and learned behaviour.
Outline the role of inheritance and learning in the development of birdsong in young birds.
Explain the effects of cocaine on mood and behaviour.
Answer/Explanation
Markscheme
innate behaviour develops independently of the environmental context/genetically
inherited and learned behaviour develops as a result of experience / OWTTE
young birds learn birdsong from parents/other adults;
young birds removed from parents capable of own song;
basic song template may be inherited;
learned birdsong is louder/richer;
(cocaine causes) dopamine build up in synapses / continuous neurotransmitter presence;
increased energy/alertness/feeling of euphoria/pleasure;
user becomes isolated/suspicious/less productive / alienates family and friends;
cocaine addiction/use may lead to crime/robbery to buy cocaine;
Question
Distinguish between innate behaviour and learned behaviour.
Outline Pavlov’s experiments into conditioning of dogs.
Answer/Explanation
Markscheme
innate behaviour develops independently of the environmental context, whereas
learned behaviour develops as a result of experience
To award [1], answers need to address both innate and learned behaviour.
Do not accept “instinct” as a description of innate behaviour.
conditioned stimulus of sound/ringing bell / other stimulus used by Pavlov;
replaces unconditioned stimulus of sight/smell of food;
both result in conditioned response/production of saliva;
Question
Outline Pavlov’s experiments into the conditioning of dogs.
Outline how sound stimuli are detected in the ear.
Answer/Explanation
Markscheme
a. classical conditioning;
b. Pavlov sounded a bell before food / conditioned stimulus;
c. dogs salivated when they heard the bell / conditioned response;
d. the amount of salivation after the bell was as great as when the food alone was presented;
e. dogs had learnt to associate the two external stimuli;
a. sound waves reaching eardrum cause it to vibrate;
b. vibrations passed to bones of middle ear/oval window/fluid in cochlea;
c. detected by mechanoreceptors/hair cells (in cochlea of ear);
Question
Label the parts of the reflex arc shown below.
Answer/Explanation
Markscheme
I. dorsal root ganglion;
II. grey matter;
III. motor neuron;