IBDP Online Test Series By iitianacademy
Comprehensive Test Preparatory package targeted towards IBDP
Question
Noise from ships has the capacity to disrupt the foraging behaviour of shore crabs (Carcinus maenas). In this study, C. maenas were collected from Newquay Harbour in the UK and held for a maximum of 48 hours in salt-water tanks located at a neighbouring aquarium. The graph shows the effect of simulated ship noise on the time spent foraging for food by C. maenas.
[Source: Republished with permission of Elsevier Science and Technology Journals, from ‘Noise negatively affects foraging and antipredator behaviour in shore crabs’, Matthew A. Wale, Stephen D. Simpson, Andrew N. Radford, Animal Behaviour 86, 2013; permission conveyed through Copyright Clearance Center, Inc]
State the effect of simulated ship noise on foraging behaviour.
Predict the consequences on C. maenas of increasing noise related to human activity.
Answer/Explanation
Markscheme
foraging behaviour disrupted more «in the presence of simulated ship noise»
a. affects searching for food/foraging/selecting optimum prey
b. increased risk of starvation/less food «for survival»
c. cause migration/relocation/moving to other foraging area
d. individuals less distracted by noise will survive
OWTTE
OR
leads to natural selection
e. decline in population
[Max 3 Marks]
Question
The shore crab (Carcinus maenas) preys on mussels (Mytilus edulis). M. edulis vary in size. The frequency distribution of the numbers of each length of M. edulis eaten by a population of C. maenas per day is shown in the graph.
State the most common length of M. edulis eaten by the C. maenas population.
Suggest reasons for the length you stated in (a) being the most common length of M. edulis that C. maenas eat.
Answer/Explanation
Markscheme
17.5 mm OR 15 mm to 20 mm
a. larger mussels too much effort to open OWTTE
OR
best ratio between effort and energy return
b. smaller mussels means more individuals have to be eaten for the same return on effort
c. greater time/predator exposure spent during foraging to obtain required daily energy
d. it «may be» the most common size available
OR
«correct mussel» size favoured by natural selection
e. the claws are best adapted to prey on mussels of this size
Question
With respect to Pavlov’s experiments with dogs, distinguish between the conditioned and unconditioned stimulus.
The bird known as the blackcap (Sylvia atricapilla) traditionally migrates from its summer breeding grounds in Central Europe to Spain and Portugal for the winter. State two adaptive advantages of bird migration.
Outline one way in which synchronized oestrus in female lions increases the chances of survival and reproduction of offspring.
Outline one way in which neurons can be altered by memory and learning.
Answer/Explanation
Markscheme
Unconditioned stimulus triggers a response automatically/innately
Sight/smell of food «naturally» triggers salivation in dogs
Conditioned stimulus is a previously neutral stimulus «eg: sound of bell»
that becomes associated with the unconditioned stimulus «and is learned»
Triggers a conditioned response, salivation with sound before food
Award [2 max] if no reference to Pavlov’s investigation.
Food is more abundant
Temperature is more tolerable
More suitable habitat
Alternative 1
Females have their cubs/are lactating at same time
Can suckle/care for each other’s cubs while others hunt
Cubs are more likely to survive when they are raised in a nursery rather than by a solitary mother
Alternative 2
A group of male cubs, of same age, leave the pride at the same time
So can compete for dominance of another pride more effectively
Involve changes in neurons caused by slow-acting neurotransmitters
Neurons make new connections/increase number of synapses
«Short-term» memory depends on change in strength of existing neuronal connections
Long-term potentiation «LTP» is a lasting increase in strength of synaptic transmission
More receptors added to enhance synaptic transmission
Question
Lizards living in the Kalahari Desert of southern Africa are diurnal (active in daylight). Scientists studied this rhythmical behaviour during different seasons of the year. Observations were made of the number of lizards active each hour and this was recorded as a percentage of the total number of lizards that were active. The graph shows the results for the Southern Spiny Agama (Agama hispida) lizard. Between the hours of 19:00 and 7:00 the lizards were inactive.
State one time in spring when 5 % of the lizards were active.
Winter and summer weather conditions differ in the Kalahari Desert. Compare the results for summer and winter.
Winter and summer weather conditions differ in the Kalahari Desert. Compare the results for summer and winter.
The temperatures differ in summer and winter. Suggest one other possible reason why the lizard activity differs in summer and winter.
The temperatures differ in summer and winter. Suggest one other possible reason why the lizard activity differs in summer and winter.
Outline one other example illustrating the adaptive value of a rhythmical behaviour pattern in a named animal.
Answer/Explanation
Markscheme
17:00
a. change in behaviour/availability of their prey/food sources;
b. change in presence of predators;
c. protection from sun (in the middle of the day in summer);
d. amount of daylight hours (is reduced in winter);
Do not accept answers related to temperature eg: cold blooded or poikilothermic.
a. change in behaviour/availability of their prey/food sources;
b. change in presence of predators;
c. protection from sun (in the middle of the day in summer);
d. amount of daylight hours (is reduced in winter);
Do not accept answers related to temperature eg: cold blooded or poikilothermic.
a. name of organism;
b. rhythmical behaviour;
c. adaptive value;
Accept common name eg: deer, bear but not category names eg: fish, bird.
eg:
a. coral;
b. male and females release gametes into the sea at the same time;
c. this increases the chances of fertilization;
Question
Each spring, the breeding season for various species of toads begins with a mass arrival of females at ponds and lakes. Males arrive later and actively compete for the females. Amplexus (mating embrace) and spawning (depositing eggs in water) then follow. Many environmental variables affect the timing of breeding. The hypothesis that periodicity in reproductive behaviour reflects periodicity in the lunar cycle was tested over several breeding seasons at sites in Wales (UK) and Italy. The lengths of the shaded bars indicate the relative frequencies of the events.
Identify which reproductive event is least influenced by the lunar cycle.
Compare the data for arrival events with amplexus events.
Deduce the relationship between arrival events and amplexus events in moon phases D to F.
The lunar cycle could affect the timing of breeding. Suggest, with a reason, one other environmental variable which could affect the timing.
Answer/Explanation
Markscheme
first spawn/spawning
frequency at full moon/E about the same;
both arrival (event) and amplexus (event) have low/similar frequencies in B and C;
highest frequency for arrival (event) in D whereas highest frequency for amplexus (event) in F;
always some arrivals but amplexus (event) only in B to F / no amplexus (event) in G/H/A;
mass arrival (events) at phases D and E is followed by large amplexus (events) at phases E and F;
full moon/lunar cycle seems to influence timing of both events (in sequence) / OWTTE;
example of environmental condition;
reason for the example;
e.g.:
rainfall;
necessary to maintain pond levels to enable the toads to spawn;
temperature / season / daylength;
affects metabolism / survival of offspring;
Question
Discuss the evolution of altruistic behaviour using one non-human example.
Answer/Explanation
Markscheme
organism expends time/energy in caring for other (unrelated) members of the same species;
put themselves at risk or disadvantage for the good of other members of the species / actions that increase another individual’s number of offspring at cost to one’s own reproduction;
valid example; (e.g. primates / vampire bats / male turkeys or other birds such as Florida jays / mole rats)
Do not accept parental care.
description of altruistic behaviour of the example given;
might expect natural selection to be against behaviour that reduces chances of survival and reproduction;
close kin share alleles;
(adaptive significance is to) increase frequency of alleles shared in common;
(provides genetic advantages in kin by) promoting survival and reproduction within species;
altruistic behaviour towards non-relatives may allow selection of alleles responsible for the behaviour to be perpetuated;
some argue no true altruism as organism benefits either directly or indirectly in the future;
Award [5 max] if no valid non-human example given.
Question
Cooperative breeding in birds occurs when more than two birds of the same species help to rear the young from one nest. For the Australian superb fairy-wren (Malurus cyaneus), mature non-breeding birds help to protect and rear the young, although they are not parents of any of them.
The bar charts below show the effect of the presence of helpers on mean egg volume, mean mass of six-day-old chicks and the probability of survival of the breeding females until the next breeding season.
State the effect of the presence of the helpers on mean chick mass.
Calculate the percentage decrease in mean egg volume found in the presence of helpers as compared to the parents only. Show your working.
With reference to the data, suggest why the activity of the helper affects the probability of survival of the breeding female until the next breeding season.
Cooperative breeding is an altruistic behaviour. Outline the evolution of altruistic behaviour.
Answer/Explanation
Markscheme
(mean) chick mass increases in presence of helpers
with helper, smaller egg volume;
less resources from mother to produce egg/rear young;
more resources toward survival of mother;
(altruistic) behaviour is inherited;
adaptations/behaviours that help the colony survive at expense of individual;
selected for (natural selection);
will be more likely to be passed on;
Question
Corals can be male, female or hermaphrodite (both male and female) and the release of their gametes is called spawning. Data was collected to study the spawning behaviour in the Gulf of Mexico of three genera of coral: Montastraea, Stephanocoenia and Diploria. The spawning behaviour is expressed in minutes post-sunset. Peak spawning windows are shown as grey bars and the range as black bars.
Suggest why it may be advantageous for each species of coral to spawn within a tight time frame.
Discuss the significance of different spawning windows for different species.
Scientists hypothesized that the release of the male gamete triggers a chemical signal for females to release their eggs. Discuss this hypothesis.
The spawning window of D. strigosa is shown as a shaded gradient indicating a strong bias towards spawning in the early portion of the window. Suggest a reason for the spawning behaviour of D. strigosa.
Define the term innate behaviour.
Answer/Explanation
Markscheme
to increase the possibilities of fertilization
a. to avoid interspecific/cross-fertilization;
b. cross-fertilization usually not successful/non-productive;
c. some overlap of species spawning occurs so temporal separation is not completely successful;
d. example of overlap (e.g. D. strigosa overlaps with M. cavernosa/M. franksi);
a. females always spawned after males suggesting hypothesis correct;
b. for example in M. cavernosa or S. intercepta;
c. difficult to tell for hermaphrodites;
d. chemical analysis of water should be undertaken after males spawned / other chemical signals / further evidence required to support cause and effect;
a. the spawning of D. strigosa is influenced by male M. cavernosa;
b. the spawning of D. strigosa is influenced by the release of M. franksi;
c. D. strigosa spawning diminishes due to the appearance (spawning) of M. franksi;
d. light intensity determined;
innate behaviour develops independently of the environmental context / not learned/ stereotyped / inherited / genetic pre-disposition
Do not accept instinct.