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CHSE Odisha Elective Psychology study materials
CHSE Odisha Elective Psychology study resources

CHSE Odisha Elective Psychology practice questions

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Question 1Introduction to Psychology: Nature, Scope, Schools and Methods

In Wilhelm Wundt's laboratory at Leipzig, the primary method used to study conscious experience was:

  1. Systematic introspection under controlled conditions Correct answer.
  2. Correlating test scores with school grades
  3. Naturalistic observation of children at play
  4. Hypnosis of clinical patients

Explanation

Wundt founded the first experimental psychology laboratory in 1879 and trained observers to report their own immediate conscious experiences under standardised conditions, a method he called introspection. He combined it with reaction-time and psychophysical measurements so that reports could be checked and compared across observers.

Question 2Introduction to Psychology: Nature, Scope, Schools and Methods

Which statement best captures the subject matter of psychology as an empirical discipline?

  1. The study of the nervous system alone
  2. The study of behaviour and mental processes Correct answer.
  3. The study of social institutions and their laws
  4. The study of the soul as a theological entity

Explanation

Modern psychology is defined as the scientific study of behaviour and mental processes, including perception, learning, memory, emotion and social interaction. This definition unites observable actions with internal processes that must be inferred from evidence.

Question 3Introduction to Psychology: Nature, Scope, Schools and Methods

A researcher argues that psychology should analyse only what can be observed and measured, discarding references to inner feelings. This position is most characteristic of:

  1. Psychoanalysis
  2. Gestalt psychology
  3. Humanistic psychology
  4. Behaviourism Correct answer.

Explanation

Behaviourism, associated with Watson and later Skinner, insisted that psychology confine itself to observable stimuli and responses rather than unobservable mental states. Watson's 1913 manifesto explicitly rejected introspection and consciousness as proper subject matter.

Question 4Introduction to Psychology: Nature, Scope, Schools and Methods

The Gestalt school, represented by Wertheimer, Köhler and Koffka, is best known for arguing that:

  1. Experience is organised into wholes that cannot be reduced to separate elements Correct answer.
  2. Individual differences are best measured by standardised tests
  3. Mental illness results from repressed childhood conflicts
  4. All behaviour is a product of stimulus-response bonds

Explanation

Gestalt psychologists held that perception and thought are structured wholes, so analysing experience into isolated sensations destroys the phenomenon being studied. Their slogan that the whole is different from the sum of its parts captures this anti-elementarist stance.

Question 5Introduction to Psychology: Nature, Scope, Schools and Methods

A psychologist studies how students encode, store and retrieve information for examinations. This work falls within which subfield of psychology?

  1. Clinical psychology
  2. Developmental psychology
  3. Cognitive psychology Correct answer.
  4. Industrial-organisational psychology

Explanation

Cognitive psychology examines internal processes such as attention, memory, problem solving and language. Encoding, storage and retrieval are the standard components of memory studied in this subfield.

Question 6Introduction to Psychology: Nature, Scope, Schools and Methods

Which method allows a researcher to establish whether a change in one variable causes a change in another?

  1. Case study
  2. Correlational survey
  3. Controlled experiment Correct answer.
  4. Naturalistic observation

Explanation

Only a controlled experiment permits causal inference, because the researcher manipulates the independent variable and randomly assigns participants, thereby controlling confounds. Correlational and observational designs reveal relationships or descriptions but cannot rule out alternative causes.

Question 7Introduction to Psychology: Nature, Scope, Schools and Methods

The variable that the experimenter deliberately manipulates in an experiment is called the:

  1. Independent variable Correct answer.
  2. Confounding variable
  3. Dependent variable
  4. Control variable

Explanation

The independent variable is the factor the experimenter changes or selects in order to observe its effect. The dependent variable is the measured outcome that is expected to depend on it.

Question 8Introduction to Psychology: Nature, Scope, Schools and Methods

A researcher records how often students visit a university counselling centre and also their reported stress levels, finding that higher stress is associated with more visits. Which conclusion is justified?

  1. The two variables are unrelated because the design is correlational
  2. High stress causes students to seek counselling
  3. Counselling visits cause students to feel stressed
  4. Stress and counselling visits are related but causality is undetermined Correct answer.

Explanation

A correlation establishes that two variables co-vary, but it cannot specify direction of influence or exclude third variables. Either causal direction, or a common cause such as examination pressure, could produce the observed association.

Question 9Introduction to Psychology: Nature, Scope, Schools and Methods

In an experiment on the effect of background music on concentration, participants choose whether to study with music or in silence. The main methodological weakness is that:

  1. The dependent variable is not measurable
  2. The independent variable has too many levels
  3. The study lacks a dependent variable
  4. Self-selection allows pre-existing differences to confound the result Correct answer.

Explanation

When participants assign themselves to conditions, group differences such as motivation or prior study habits may explain the outcome instead of the music. Random assignment is the standard safeguard that this design omits.

Question 10Introduction to Psychology: Nature, Scope, Schools and Methods

A clinical psychologist spends two years documenting the history, symptoms and treatment response of a single patient with a rare disorder. The chief limitation of this approach is that:

  1. Findings from one case cannot be generalised with confidence Correct answer.
  2. It cannot be conducted in a clinical setting
  3. It cannot provide detailed descriptive information
  4. It requires manipulation of an independent variable

Explanation

The case-study method yields rich, detailed data but suffers from limited generalisability because a single individual may be atypical. It also cannot establish causation, although it is valuable for generating hypotheses about rare conditions.

Question 11Introduction to Psychology: Nature, Scope, Schools and Methods

Which pairing of school and central concept is correct?

  1. Structuralism - observable responses only
  2. Humanistic psychology - self-actualisation Correct answer.
  3. Behaviourism - unconscious conflict
  4. Psychoanalysis - reinforcement schedules

Explanation

Humanistic psychology, associated with Maslow and Rogers, places self-actualisation and the person's subjective striving for growth at its centre. Each other pairing mismatches a school with a concept belonging to a different tradition.

Question 12Introduction to Psychology: Nature, Scope, Schools and Methods

The chief criticism that led psychologists to abandon strict introspection was that:

  1. It relied too heavily on animal subjects
  2. It required expensive laboratory equipment unavailable at the time
  3. Reports of inner experience could not be independently verified or replicated Correct answer.
  4. It produced too much quantitative data

Explanation

Introspective reports are private and were often inconsistent between observers and laboratories, so they failed the requirement of public verifiability. This unreliability, together with behaviourism's rise, pushed psychology toward observable measures.

Question 13Introduction to Psychology: Nature, Scope, Schools and Methods

A school teacher wants to know whether a new reward system improves spelling accuracy in Class VIII. Which design most directly answers the question?

  1. Compare spelling scores of a class given rewards with a comparable class given none Correct answer.
  2. Administer a personality test to the whole class
  3. Review the historical origins of reward in psychology
  4. Interview the teacher about her impressions of the reward system

Explanation

Testing the effect of a reward system requires comparing an outcome measure, spelling accuracy, between a group receiving the reward and a comparable group not receiving it. This is a quasi-experimental comparison that isolates the influence of the reward.

Question 14Introduction to Psychology: Nature, Scope, Schools and Methods

The debate over whether heredity or environment is the stronger determinant of behaviour is known as the:

  1. Mind-body problem
  2. Nomothetic-idiographic debate
  3. Nature-nurture controversy Correct answer.
  4. Consciousness paradox

Explanation

The nature-nurture controversy concerns the relative contributions of genetic inheritance and environmental experience to behaviour and traits. Contemporary psychology treats the two as interacting rather than as competing forces.

Question 15Introduction to Psychology: Nature, Scope, Schools and Methods

Which feature distinguishes a psychologist from a psychiatrist in the Indian context?

  1. A psychologist holds a medical degree and may prescribe drugs
  2. A psychiatrist holds a medical degree and may prescribe drugs Correct answer.
  3. A psychologist is only permitted to teach in schools
  4. A psychiatrist is restricted to laboratory research

Explanation

Psychiatry is a medical speciality, so a psychiatrist completes an MBBS followed by postgraduate training in psychiatry and can prescribe medication. Psychologists typically hold degrees in psychology and offer assessment, counselling and therapy without medical prescribing rights.

Question 16Introduction to Psychology: Nature, Scope, Schools and Methods

A researcher studying aggression in a nursery observes children through a one-way mirror so that they are unaware of being watched. This procedure is intended mainly to:

  1. Introduce an independent variable
  2. Eliminate the need for consent from guardians
  3. Increase the sample size
  4. Reduce reactivity so behaviour remains natural Correct answer.

Explanation

Concealed observation reduces reactivity, the tendency of people to alter their behaviour when they know they are observed. It therefore yields more naturalistic data, though ethical safeguards such as guardian consent and debriefing remain necessary.

Question 17Introduction to Psychology: Nature, Scope, Schools and Methods

Which statement about the scope of psychology is most accurate?

  1. It studies only abnormal behaviour and its treatment
  2. It studies only the physiology of the brain
  3. It studies behaviour and mental processes across diverse settings and populations Correct answer.
  4. It studies only human beings in laboratory settings

Explanation

Psychology's scope extends from biological bases of behaviour to social interaction, development, education, work and clinical practice, and includes animal as well as human research. Its methods range from laboratory experiments to field studies and surveys.

Question 18Introduction to Psychology: Nature, Scope, Schools and Methods

The psychodynamic approach differs from behaviourism chiefly in that it:

  1. Emphasises unconscious motives and early childhood experiences Correct answer.
  2. Focuses exclusively on group behaviour
  3. Rejects the study of personality altogether
  4. Relies on observable stimulus-response connections

Explanation

The psychodynamic approach, stemming from Freud, explains behaviour through unconscious drives, conflicts and early developmental experiences. Behaviourism, by contrast, restricts itself to observable behaviour and environmental contingencies.

Question 19Introduction to Psychology: Nature, Scope, Schools and Methods

A team studies how the presence of bystanders affects the speed with which a person offers help. Which combination of goal and method fits this study?

  1. Prediction through archival analysis of old newspapers
  2. Explanation through a controlled experiment Correct answer.
  3. Description through a case study
  4. Control through introspection

Explanation

The study tests a causal hypothesis about bystander presence and helping speed, which requires an experiment in which the number of bystanders is manipulated. Measuring helping latency provides the dependent variable needed to explain the effect.

Question 20Introduction to Psychology: Nature, Scope, Schools and Methods

Which of the following best illustrates psychology's goal of prediction?

  1. Applying relaxation training to reduce a client's anxiety
  2. Describing the symptoms observed in a patient
  3. Explaining why a student failed an examination
  4. Using aptitude scores to forecast which candidates will succeed in a job Correct answer.

Explanation

Prediction involves using known information to forecast future behaviour or outcomes, as when aptitude scores anticipate job success. Explanation accounts for causes, description records what occurs, and control or influence involves changing behaviour.

Question 21Introduction to Psychology: Nature, Scope, Schools and Methods

Two observers independently rate the same classroom for disruptive behaviour and obtain closely similar scores. This result provides evidence of:

  1. Ecological validity
  2. Construct validity
  3. Inter-rater reliability Correct answer.
  4. Internal validity

Explanation

Inter-rater reliability refers to the degree of agreement between independent observers using the same instrument. High agreement suggests that the observation schedule is applied consistently rather than reflecting the idiosyncrasies of one rater.

Question 22Introduction to Psychology: Nature, Scope, Schools and Methods

A researcher finds that participants who sleep fewer hours report more anxiety symptoms, with a correlation of r = -0.62. Which interpretation is most defensible?

  1. Reduced sleep directly causes anxiety
  2. Anxiety directly causes reduced sleep
  3. Shorter sleep is moderately to strongly associated with greater anxiety, but the causal path is unclear Correct answer.
  4. The correlation is too weak to be meaningful

Explanation

A value of -0.62 indicates a moderate-to-strong negative relationship, so less sleep goes with more anxiety. Because the design is correlational, the direction of influence and possible third variables remain unresolved.

Question 23Introduction to Psychology: Nature, Scope, Schools and Methods

An experiment tests a new therapy for examination anxiety. Volunteers are assigned randomly, and neither participants nor the therapists scoring anxiety know who receives the active therapy. The main purpose of this double-blind arrangement is to:

  1. Increase the number of participants available
  2. Ensure that the independent variable is measured rather than manipulated
  3. Guarantee that the therapy is effective
  4. Prevent expectancy effects from biasing the results Correct answer.

Explanation

Double-blind procedures prevent participant expectancy and experimenter bias from contaminating the outcome, protecting internal validity. They are safeguards against bias, not guarantees of a positive result or devices for increasing sample size.

Question 24Introduction to Psychology: Nature, Scope, Schools and Methods

A study on the effect of noise on concentration is conducted in a silent laboratory but claims to describe how students concentrate in crowded examination halls. The most serious problem is that the study lacks:

  1. Internal validity
  2. Random sampling of variables
  3. Inter-rater reliability
  4. Ecological validity Correct answer.

Explanation

Ecological validity concerns whether findings obtained in artificial settings generalise to real-world conditions. A silent laboratory differs markedly from a crowded hall, so the conclusion may not transfer to the setting it claims to describe.

Question 25Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

In a neuron at resting potential, the inside of the axon membrane is electrically negative relative to the outside. Which combination of ion distributions best explains this resting negativity?

  1. An equal concentration of sodium and potassium ions on both sides of the membrane with free permeability to both
  2. A high concentration of chloride ions inside the axon and a membrane completely impermeable to all ions
  3. A high concentration of sodium ions outside the membrane and a high concentration of potassium ions inside, with the membrane more permeable to potassium at rest Correct answer.
  4. A high concentration of potassium ions outside the membrane and a high concentration of sodium ions inside

Explanation

At rest the sodium-potassium pump keeps sodium concentrated outside and potassium concentrated inside the neuron. Because the resting membrane is far more permeable to potassium than to sodium, potassium leaks outward and leaves the inner surface negatively charged. This unequal distribution and selective permeability together produce the resting potential of about minus seventy millivolts.

Question 26Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A drug blocks the reuptake of serotonin from the synaptic cleft. What is the immediate consequence for the postsynaptic neuron?

  1. The postsynaptic neuron becomes unable to produce any action potential
  2. Serotonin is destroyed faster, so postsynaptic stimulation ends sooner
  3. Sodium channels on the postsynaptic membrane close permanently
  4. Serotonin remains in the cleft longer, so postsynaptic receptors are stimulated for a prolonged period Correct answer.

Explanation

Reuptake is the normal mechanism by which neurotransmitter is cleared from the synaptic cleft and returned to the presynaptic terminal. Blocking it leaves more serotonin available to bind postsynaptic receptors for a longer time, prolonging the postsynaptic effect. Many antidepressant drugs act by inhibiting serotonin reuptake in exactly this way.

Question 27Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

Which structure of the hindbrain is chiefly responsible for regulating breathing, heart rate and blood pressure?

  1. Medulla oblongata Correct answer.
  2. Corpus callosum
  3. Thalamus
  4. Cerebellum

Explanation

The medulla oblongata contains vital centres that control respiration, cardiac rhythm and blood pressure, which is why damage to it is often fatal. The cerebellum coordinates movement and balance, the thalamus relays sensory information, and the corpus callosum connects the hemispheres, so none of these carries the vital autonomic functions named.

Question 28Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A patient who has suffered damage to the left cerebral hemisphere shows difficulty in understanding and producing spoken language. Which function of the left hemisphere does this most directly illustrate?

  1. Regulation of body temperature by the left hemisphere
  2. Control of the left side of the body by the left hemisphere
  3. Exclusive control of visual perception by the left hemisphere
  4. Language dominance of the left hemisphere in most people Correct answer.

Explanation

In the majority of people the left hemisphere is dominant for language, with Broca's and Wernicke's areas located there. Damage to these regions produces the comprehension and production difficulties described. Motor control is crossed, so each hemisphere controls the opposite side of the body.

Question 29Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

Which gland is often called the master endocrine gland because its hormones regulate the activity of several other endocrine glands?

  1. Adrenal gland
  2. Pituitary gland Correct answer.
  3. Pancreas
  4. Thyroid gland

Explanation

The pituitary gland secretes trophic hormones such as TSH, ACTH and gonadotropins that control the thyroid, adrenal cortex and gonads respectively. Because of this regulatory role it is conventionally called the master gland. The thyroid, adrenals and pancreas are targets or independent sources of hormones rather than the controlling centre.

Question 30Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A zygote receives one chromosome of each pair from the mother and one from the father. What term describes this paired genetic constitution of an individual?

  1. Karyotype band
  2. Mutation
  3. Genotype Correct answer.
  4. Phenotype

Explanation

The genotype is the particular combination of alleles an individual carries for a trait, one inherited from each parent. The phenotype is the observable expression of that genotype in interaction with the environment. A mutation is a change in genetic material, not the paired constitution itself.

Question 31Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A neuron is stimulated and its membrane potential rises from minus seventy to minus fifty-five millivolts, the threshold level. What event is triggered at this point?

  1. Voltage-gated sodium channels open and an action potential is generated Correct answer.
  2. Potassium channels open and the neuron becomes hyperpolarised
  3. The neuron releases neurotransmitter without firing
  4. The membrane becomes permanently impermeable to sodium

Explanation

When depolarisation reaches threshold, voltage-gated sodium channels open and sodium rushes inward, producing the rapid upswing of the action potential. This is an all-or-none event once threshold is crossed. Hyperpolarisation occurs later, during the falling phase and refractory period.

Question 32Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

An impulse travels along a myelinated axon much faster than along an unmyelinated axon of the same diameter. Which property of myelin explains this?

  1. Myelin removes the need for any ion movement during conduction
  2. Myelin insulates the axon so the impulse jumps between nodes of Ranvier Correct answer.
  3. Myelin increases the diameter of the axon
  4. Myelin converts the electrical impulse into a chemical one along the axon

Explanation

Myelin is a fatty sheath that insulates the axon and restricts ion exchange to the gaps called nodes of Ranvier. The action potential therefore regenerates at successive nodes, a process called saltatory conduction, which is far quicker than continuous conduction. This is why demyelinating diseases slow neural transmission.

Question 33Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

The hypothalamus releases corticotropin-releasing hormone, which stimulates the pituitary to secrete ACTH, which in turn stimulates the adrenal cortex to release cortisol. High cortisol then reduces further release of the earlier hormones. What is this control pattern called?

  1. Positive feedback amplification of the stress response
  2. Negative feedback regulation of the hypothalamic-pituitary-adrenal axis Correct answer.
  3. Antagonistic inhibition by the thyroid gland
  4. Irreversible hormonal cascade without regulation

Explanation

This chain is the hypothalamic-pituitary-adrenal axis, and cortisol feeds back to suppress CRH and ACTH secretion. Such negative feedback keeps hormone levels within a stable range and prevents over-secretion. Positive feedback would amplify rather than restrain the response.

Question 34Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

In a study of identical twins raised in separate families, both twins show similar scores on a test of emotional stability. Which inference is most appropriate from this finding?

  1. Shared genetic inheritance contributes to the similarity, but environmental effects cannot be ruled out Correct answer.
  2. Environment alone determines emotional stability, since the twins lived apart
  3. Emotional stability is entirely inherited and cannot be modified
  4. The similarity proves that the twins were not truly identical

Explanation

Identical twins share all their genes, so similarity between twins raised apart points to a genetic contribution to the trait. However, separated twins may still share prenatal conditions and similar placement environments, so environmental influence cannot be excluded. Heritability estimates therefore describe populations and always leave room for environmental effects.

Question 35Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A person experiences a sudden threatening situation and feels a rapid surge of energy, faster heartbeat and raised blood glucose. Which hormone most directly produces this rapid response?

  1. Adrenaline secreted by the adrenal medulla Correct answer.
  2. Insulin secreted by the pancreas
  3. Thyroxine secreted by the thyroid gland
  4. Progesterone secreted by the ovaries

Explanation

Adrenaline, released from the adrenal medulla under sympathetic nervous system control, rapidly raises heart rate, dilates airways and mobilises glucose for the emergency response. Its effects begin within seconds, which suits sudden threat. Thyroxine acts slowly on metabolic rate and does not produce this immediate surge.

Question 36Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

When a person moves the right hand voluntarily, the motor commands originate in the left hemisphere. Which principle of nervous system organisation does this illustrate?

  1. Contralateral control of the body by the cerebral hemispheres Correct answer.
  2. Bilateral symmetry of motor commands in both hemispheres
  3. Ipsilateral control of the body by the cerebral hemispheres
  4. Autonomic control of skeletal muscles by the medulla

Explanation

Motor pathways cross the midline, so each hemisphere controls voluntary movement on the opposite side of the body. This crossing, or decussation, explains why a left-hemisphere stroke can weaken the right arm. Ipsilateral control would mean each hemisphere controls the same side, which is not the case for voluntary movement.

Question 37Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

The nervous system is divided into the central and peripheral divisions. Which structures belong to the central nervous system?

  1. Sympathetic and parasympathetic nerves
  2. Cranial nerves and spinal nerves
  3. Brain and spinal cord Correct answer.
  4. Sensory receptors in the skin

Explanation

The central nervous system consists of the brain and the spinal cord, which integrate information and generate responses. The peripheral nervous system comprises the cranial and spinal nerves together with their branches and ganglia. Autonomic divisions and receptors are peripheral components.

Question 38Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A child inherits one dominant allele and one recessive allele for a trait but shows only the dominant characteristic. What does this demonstrate about the relationship between the two alleles?

  1. The recessive allele has been lost from the chromosomes
  2. The dominant allele masks the expression of the recessive allele in the phenotype Correct answer.
  3. Both alleles are expressed equally, producing a blended phenotype
  4. The trait is controlled by a gene on the sex chromosomes

Explanation

In simple dominance, a single dominant allele is sufficient to produce the dominant phenotype, so the heterozygous child resembles the dominant form. The recessive allele is still present in the genotype and can be passed on to offspring. Only when two recessive alleles are inherited does the recessive trait appear.

Question 39Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

Which lobe of the cerebral cortex contains the primary visual area that receives impulses from the retina?

  1. Frontal lobe
  2. Parietal lobe
  3. Occipital lobe Correct answer.
  4. Temporal lobe

Explanation

The primary visual cortex lies in the occipital lobe at the back of the brain and receives input relayed through the thalamus from the retina. The frontal lobe carries motor and executive functions, the temporal lobe handles hearing and some memory, and the parietal lobe processes somatosensory information.

Question 40Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A tumour compresses the pituitary gland so that its secretion of antidiuretic hormone falls. Which disturbance is most likely to result?

  1. Excessive retention of water with concentrated urine
  2. Impaired digestion of proteins in the stomach
  3. Excessive urine production and a tendency to dehydration Correct answer.
  4. Loss of voluntary muscle control

Explanation

Antidiuretic hormone, released from the posterior pituitary, increases water reabsorption in the kidney tubules. When its secretion falls, large volumes of dilute urine are lost, leading to thirst and risk of dehydration. Water retention would occur with excess, not deficiency, of the hormone.

Question 41Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A drug prevents the release of acetylcholine at the neuromuscular junction. Which immediate effect should be expected?

  1. Sensory receptors in the skin stop responding to touch
  2. Skeletal muscle fibres fail to receive the excitatory signal and cannot contract Correct answer.
  3. The heart rate rises sharply through sympathetic activation
  4. Skeletal muscles contract continuously without relaxation

Explanation

Acetylcholine is the neurotransmitter that carries the excitatory signal from motor neurons to skeletal muscle fibres. Without its release, the muscle membrane is not depolarised and contraction cannot be initiated, producing weakness or paralysis. Continuous contraction would require excess rather than absent transmitter.

Question 42Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A researcher finds that a trait shows a much higher concordance rate in monozygotic twins than in dizygotic twins. Which conclusion is best supported?

  1. The trait cannot be studied using twin methods
  2. The trait is caused entirely by environmental factors shared by twins
  3. Genetic factors contribute substantially to the trait, since monozygotic twins share more genes Correct answer.
  4. Dizygotic twins are more genetically similar than monozygotic twins

Explanation

Monozygotic twins share all their genes while dizygotic twins share about half, so a higher concordance in monozygotic pairs indicates a genetic contribution. The comparison controls broadly for shared environment because both types of twins are raised together. It does not prove complete genetic determination.

Question 43Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A person suffers damage to the cerebellum. Which pattern of symptoms is most consistent with this damage?

  1. Complete failure to regulate blood glucose
  2. Inability to feel pain in the hands and feet
  3. Clumsy, uncoordinated movements and poor balance while walking Correct answer.
  4. Loss of the ability to understand spoken language

Explanation

The cerebellum fine-tunes motor activity, maintains posture and coordinates balance, so its damage produces ataxia, tremors and unsteady gait. Language comprehension depends on cortical language areas and pain sensation on somatosensory pathways. Blood glucose is regulated hormonally by the pancreas.

Question 44Biological Bases of Behaviour: Nervous System, Endocrine System and Genetics

A hormone is injected that cannot cross the cell membrane, yet it alters gene transcription in its target cell. Which mechanism best accounts for this effect?

  1. The hormone binds a membrane receptor that activates an intracellular second messenger which then influences gene expression Correct answer.
  2. The hormone opens sodium channels and triggers an action potential that edits genes
  3. The hormone is converted into a neurotransmitter at the synapse
  4. The hormone diffuses through the membrane and binds directly to DNA in the nucleus

Explanation

Peptide and protein hormones are too large and water-soluble to cross the lipid bilayer, so they act through surface receptors coupled to second messenger systems. These intracellular signals can reach the nucleus and modify the transcription of specific genes. Steroid hormones, by contrast, are lipid-soluble and can enter the cell to bind intracellular receptors.

Question 45Sensation, Perception and Attention

In the study of sensation, the process by which a stimulus energy is converted into a neural impulse is called:

  1. Adaptation
  2. Transduction Correct answer.
  3. Perception
  4. Attention

Explanation

Transduction is the conversion of physical energy (such as light or sound waves) into electrical signals in the nervous system. It is the first step in sensation, occurring in sensory receptors.

Question 46Sensation, Perception and Attention

The minimum amount of stimulus energy needed for a stimulus to be detected 50 percent of the time is known as the:

  1. Difference threshold
  2. Just noticeable difference
  3. Subliminal threshold
  4. Absolute threshold Correct answer.

Explanation

The absolute threshold is defined as the weakest level of a stimulus that can be detected half the time. It marks the boundary between not sensing and sensing a stimulus.

Question 47Sensation, Perception and Attention

Weber's law states that the just noticeable difference (JND) between two stimuli is:

  1. A constant absolute amount regardless of stimulus intensity
  2. Always equal to the absolute threshold
  3. A constant proportion of the original stimulus intensity Correct answer.
  4. Larger for stronger stimuli in direct proportion to their intensity

Explanation

Weber's law asserts that the JND is a constant fraction of the original stimulus magnitude. For example, if the JND for weight is 1/50, then 2 grams must be added to 100 grams, but 4 grams to 200 grams.

Question 48Sensation, Perception and Attention

Which theory of color vision explains the phenomenon of negative afterimages?

  1. Frequency theory
  2. Trichromatic theory
  3. Place theory
  4. Opponent-process theory Correct answer.

Explanation

The opponent-process theory posits that color perception is based on three opposing pairs (red-green, blue-yellow, black-white). When one member of a pair is fatigued, the opposite color is perceived as an afterimage.

Question 49Sensation, Perception and Attention

The gate-control theory of pain proposes that:

  1. Pain receptors are located only in the skin
  2. Pain signals can be blocked or facilitated by neural mechanisms in the spinal cord Correct answer.
  3. Pain is a purely psychological phenomenon with no physiological basis
  4. Pain perception is determined solely by the intensity of the stimulus

Explanation

The gate-control theory suggests that the spinal cord contains a neurological 'gate' that can open or close to modulate the transmission of pain signals. Factors such as attention, expectation, and small-fiber activity influence whether the gate is open or closed.

Question 50Sensation, Perception and Attention

The perception of depth that relies on both eyes working together, such as retinal disparity, is called:

  1. Motion parallax
  2. Binocular depth cue Correct answer.
  3. Monocular depth cue
  4. Pictorial depth cue

Explanation

Binocular depth cues require the use of both eyes and include retinal disparity and convergence. They provide strong information about depth because each eye receives a slightly different image.