SL Paper 3
To test hearing, sounds are played at very low volume levels and gradually increased until the patient can hear the sound. This is repeated with different frequencies which correspond to low or high pitch sounds. The results are marked on an audiogram. This audiogram is from a 60-year-old woman.
Human speech occurs at a volume of approximately 60 dB and at frequencies between 125 Hz and 4000 Hz. Outline whether the woman would hear all conversations with both ears.
The woman suffers from otosclerosis in the right ear, a condition where the bones of the middle ear do not function properly. Describe how this is consistent with the hearing test result shown in the audiogram.
Explain the role of the hair cells in the cochlea.
The diagram shows the early development of the nervous system in embryonic chordates.
Outline the process taking place in the diagram.
State what occurs to structure X immediately following its formation.
Outline how spina bifida could occur during embryonic development.
The images show the brains of human (Homo sapiens) and baboon (Papio hamadryas). The images are not drawn to scale.
(i) Identify the structure labelled X.
(ii) Outline the function of X in the human brain
With reference to structures visible in the diagrams, explain how the human brain is more evolved for higher order functions than the baboon brain.
The image shows a human eye.
Identify the structures labelled I and II
Explain how the pupil of the eye can be used to assess brain damage.
The diagram shows a photoreceptor and an olfactory receptor. The arrows show the direction of the stimulus.
State the name of the photoreceptor shown.
Distinguish between a photoreceptor and an olfactory receptor.
In a study of brain organization, several factors were investigated. The relationship between the volumes of grey and white matter across mammalian species was compared.
Describe the relationship between the volume of white matter and grey matter.
Outline the organization of the human cerebral cortex with regard to structure and function.
Outline one reason for the large energy requirement of the brain.
The diagram shows the anatomy of the human ear.
Label the cochlea on the diagram.
Explain the structure of the semicircular canals in relation to their functions.
Explain the role of ganglion cells in the eye.
The photomicrographs below show time lapse images of a migrating neuron in the grey matter of the cerebrum of an embryo. The time lapse images were taken at one hour intervals. The cell body is the rounded bright area towards the rear of the migrating neuron.
Calculate the rate of movement of the neuron cell body between 0 and 5 h. Working should be shown, giving the units.
Suggest a reason for the migration of neurons in the embryonic nervous system.
Outline neural pruning.
The images show the early stages and completed outcome of the process of neurulation.
Label the parts I and II on the images.
Structure Y will eventually elongate to form two structures. State the names of these two structures.
1.
2.
State the condition that arises if the closure of structure X is incomplete during embryonic development.
The cortex of the brain consists of several regions.
State whether this view of the brain shows the left side or the right side.
Outline the function of Broca’s area.
The hearing threshold is how loud a sound needs to be before an individual can perceive the sound. The chart shows the mean value of the hearing threshold for hearing-impaired individuals before and after receiving a cochlear implant. Normal human speech has a range of loudness of from 50 to 60 decibels (dB).
[Source: This article was published in Brazilian Journal of Otorhinolaryngology, Volume number
81, issue 2, Caixeta Guimarães, A., Machado de Carvalho, G., Duarte, A.S.M., Bianchini, W.A., Bravo Sarasty, A.,
di Gregorio, M.F., Zernotti, M.E., Sartorato, E.L., Menino Castilho, A., Hearing preservation and cochlear implants
according to inner ear approach: multicentric evaluation., pp.190–196 , Copyright Elsevier (2015).]
Outline the effect of the cochlear implant on hearing.
Suggest, with reference to the structure of the ear, a reason that a cochlear implant requires an amplifier.
Describe the normal function of the cochlea.
Explain how autopsy and lesions can be used to identify the role of different brain parts.
The diagram shows rays of light entering the eyes from point Q in the right visual field.
Draw a ray of light entering the left eye from point P.
Information about the light from P entering the left eye is processed in the brain.
State what region of the brain would process the information.
Information about the light from P entering the left eye is processed in the brain.
State the side of the brain that would process the information.
State the type of cell in the retina which directly transmits impulses through the optic nerve to the brain.
The diagram shows the human brain.
[Source: By charlyzon (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons.]
Identify the structure labelled A.
List two functions of the structure labelled A.
Outline the reason that Broca’s area is more developed in humans than other primates.
Suggest how an injury to the brain can help in understanding brain function.
The diagram shows part of a retina.
[Source: C. J. Clegg, Introduction to Advanced Biology, 2000, p. 285. Reproduced by permission of Hodder Education.]
Identify the cell labelled X.
Draw an arrow to show the direction of light through the retina.
The image shows a human ear.
[Source: Leonello/iStock]
Using the letter M, label the structures which detect movement of the head.
Using the letter A, label where sound is amplified.
Explain the function of the cochlea in hearing.
Outline how the hearing of a deaf or partially deaf person could be improved.
The energy used by the brain and skeletal muscle of a 70 kg man was measured over the period of one day.
The metabolic rate is the energy used per kilogram of mass per day. Calculate the metabolic rate of the brain.
Using only the data in the table, distinguish between the use of energy in the brain and in skeletal muscle.
Suggest one reason for the difference between the brain and skeletal muscle in metabolic rate.
Outline the role of the brain in involuntary control.
The drawings show the development of an immature neuron in a rat.
Describe the process taking place.
Outline the possible changes to this neuron that could happen during the subsequent development of the nervous system.
Suggest how the plasticity of the brain can benefit humans.
The image shows an external view of the human ear.
Identify the structure labelled X.
Explain how sound from an outside source causes movement of the hair cells in the cochlea.
The diagram shows a magnetic resonance image (MRI) of a human brain.
On the diagram, label the visual cortex.
Identify the structure labelled X.
Explain how a functional MRI (fMRI) can be used to identify the function of parts of the brain.
Label the pupil and the retina on the diagram.
[Source: Holly Fischer https://en.wikipedia.org/wiki/Human_eye#/media/File:Three_Internal_chambers_of_the_Eye.png]
Explain the use of the pupil reflex as a test for brain damage.
State the property of the nervous system that allows it to change with experience and allows the brain to recover from a stroke.
Explain the stages of development and differentiation of neurons.
The diagram shows the components of a cochlear implant system.
Identify the part of the ear labelled X.
Compare and contrast the mechanisms involved in hearing sounds in individuals with and without cochlear implants.
Outline the role of the ear in balance perception.
Explain how information from the left and right sides of the visual field is processed.
The graph shows the energy consumption of photoreceptors in three different species of fly (Drosophila melanogaster, Drosophila virilis and Sarcophaga carnaria) at the mean of the highest transmission rate for each species at rest and while sending a nerve signal (signalling).
Outline the function of one named photoreceptor in the mammalian eye.
Explain how neurons at rest still consume energy.
Identify the species with photoreceptors that have the fastest signalling transmission rate.
Describe the relationship between energy consumption and transmission rate.
Explain the neural control of swallowing.
Neurons are initially produced by differentiation in the neural tube. Outline the mechanisms of axon and synapse development that follow the initial creation of neurons.
The scan shows the brain of a patient affected by a stroke. The dark patch labelled X represents an area where cells have died.
[Source: Case courtesy of Dr Ahmed Abdrabou, Radiopaedia.org, rID: 36865]
State the name of the general area of the brain affected by this stroke.
Explain how patient recovery from a stroke illustrates the property of neural plasticity.
Explain how studies of lesions have helped to identify the functions of different parts of the brain.
A person was given a visual stimulus while an image was taken of their brain.
State the name of the technique used to produce the image.
Identify the area of the brain responsible for processing visual stimuli.
Identify the area of the brain labelled X in the image.
The diagram illustrates the sensitivity to sound frequencies, measured in Hz, of the different regions of the semicircular canal. The base is the region closest to the oval window.
[Source: © International Baccalaureate Organization 2019]
The diagram shows the human ear.
[Source: Didier Descouens, https://commons.wikimedia.org/wiki/Category:Human_middle_ear#/media/File:Place-desosselets-
Schema.jpg, licensed under CC BY-SA 3.0]
Outline the relationship between the distance from the oval window and the sound frequency detected.
State the range of sound frequencies detected by the ear.
Sensory receptors are divided into different categories. Hair cells in the cochlea are sensory receptors. State the category to which they belong.
Identify the structure labelled Y in the diagram.
Annotate the diagram with an X to show the internal location where a cochlear implant is placed.
Outline the function of the stapes.
The diagrams illustrate changes in synapse density of the cerebral cortex from newborn to adult.
[Source: THE POSTNATAL DEVELOPMENT OF THE HUMAN CEREBRAL CORTEX, VOLUMES IVIII, by Jesse LeRoy Conel, Cambridge, Mass.: Harvard University Press, Copyright © 1939, 1941, 1947, 1951, 1955, 1959, 1963, 1967
by the President and Fellows of Harvard College. Copyright © renewed 1967, 1969, 1975, 1979, 1983, 1987, 1991.]
Explain the processes illustrated by the diagrams.
Scientists investigated how relative brain mass varied in primate evolution. The graph shows the relative brain mass for species belonging to different primate groups against time of divergence from the common ancestor of modern humans in million years ago (Mya), 0 being the present era.
[Source: S Herculano-Houzel and J H Kaas, (2011), Brain, Behavior and Evolution, 77, pages 33–44.
© 2011 Karger Publishers, Basel, Switzerland]
State the trend in relative brain mass in primates other than humans according to their time of divergence from humans.
Suggest one reason that the relative brain mass of Homo is different from Parapithecus and Australopithecus.
Deduce, with a reason, whether the relative brain mass is a good indicator of brain development.
Primates belong to the phylum chordata. The neural tube of chordates is formed by the infolding of the ectoderm followed by the elongation of the tube. Outline the process of formation of neurons from this neural tube in primates.
Hearing loss can range from mild to severe. Cochlear implants have been used in those with profound hearing loss such as children who are born deaf. The image shows a cross section of the ear with a cochlear implant.
[Source: NIDCD (www.nidcd.nih.gov/health/cochlear-implants)]
Identify the parts of the ear labelled X and Y.
X:
Y:
Describe the use of cochlear implants in deaf patients.
Explain the autonomic control of the pupil of the eye and how the pupil reflex is used to determine brain damage.
The graph shows the relationship between body mass and brain volume in three groups of primates.
Analyse the relationship between body mass and brain volume in these primates.
The performance of mice on a Barnes maze, shown in the photograph, was used to test the effect of cinnamon on learning.
Mice were trained for three days to find a compartment in the maze containing food. Their ability to find the compartment was tested by placing the mice at the centre and recording their movement. The mice were divided into two groups according to the route taken: good performers and poor performers. After this all the mice were fed a small amount of cinnamon in their diet for 30 days. They were then trained for three days and retested on the maze.
The diagrams show the movements of a typical good performer and a typical poor performer before and after cinnamon was included in their diet.
[Source: reprinted by permission from: Springer Natures, Journal of NeuroImmune Pharmacology, Cinnamon Converts Poor
Learning Mice to Good Learners: Implications for Memory Improvement, Khushbu K.Modi et al, copyright 2016]
Describe how the use of cinnamon changes mouse performance on the Barnes maze.
Scientists demonstrated that cinnamon increased neural plasticity in some parts of mouse brains. Explain how neural plasticity could have affected learning in poor performer mice.
It has been suggested that cinnamon might be of benefit to patients who are recovering from a stroke. Suggest one advantage of adding cinnamon to the diet of a patient who has suffered a stroke.
The image shows a normal human brain in vertical section.
Identify the parts of the brain labelled X and Y.
Outline the function of the nucleus accumbens.
Compare and contrast the sensory and motor functions of the left and right cerebral hemispheres of the brain.
Cells destined to become neurons differentiate in the neural tube. They grow and mature under the influence of chemical and other signals. The influence of insulin-like growth factor (IGF) was investigated in vitro using olfactory sensory neurons. The turning angle (direction) and extension of growth of these neurons were measured.
Evaluate the claim that IGF influences turning angle and neuron extension.
Outline the development of neurons from when they are first formed in the neural tube.
The development of the neural tube in the frog Xenopus is shown in the diagram.
[Source: reprinted by permission from Nature Reviews Neuroscience, Gammill, L., Bronner-Fraser, M.
Neural crest specification: migrating into genomics. Nat Rev Neurosci 4, 795–805 (2003) doi:10.1038/nrn1219]
State the name of the stage of embryonic development shown in the diagram.
Identify the part labelled X.
State a consequence of incomplete folding of the neural tube in humans.
Explain how the nervous system develops from the cells of the neural tube.
The MRI brain scans show the cerebral hemispheres of two people of the same age, one of whom is suffering from multiple sclerosis and has lost motor functions.
[Source: © Frontiers in Bioscience. Role of MRI in Multiple Sclerosis II: Brain and Spinal
Cord Atrophy, Robert Zivadinov and Rohit Bakshi, 9, 647–664, January 1, 2004]
Identify the structures found at I, II and III.
I:
II:
III:
Suggest one way in which multiple sclerosis has affected the cerebral hemispheres of the brain.
The folding of the cerebral hemispheres is extensive and varies between different mammals. Explain briefly the importance of folding of the cerebral hemispheres in humans.
The diagram shows part of a human retina.
[Source: reprinted by permission from Springer Nature: Nature Reviews Neuroscience Parallel processing in
the mammalian retina, Heinz Wässle, 2004, Nat Rev Neurosci 5, 747–757 (2004) doi:10.1038/nrn1497]
On the diagram, draw an arrow showing the direction of the light.
Identify the cells labelled A and B.
A:
B:
Explain, using the diagram, how the visual stimuli from the right eye reach the visual cortex of the brain.
Outline the function of the autonomic nervous system in the human body.
Evaluate the use of the pupil reflex to test for brain damage.
Discuss the methods used to identify the role of specific parts of the brain.
Describe how the inner ear detects audible sounds.