BAPSY Biological Bases of Behavior 4 — Questions and Answers
Question 1: The circadian rhythm is primarily regulated by which brain structure?
- Pineal gland
- Suprachiasmatic nucleus (SCN) (Correct answer)
- Reticular formation
- Substantia nigra
Correct answer: Suprachiasmatic nucleus (SCN)
The suprachiasmatic nucleus in the hypothalamus serves as the body's master clock, synchronizing circadian rhythms to light-dark cycles.
Question 2: In an EEG, which brain wave pattern is associated with deep, dreamless sleep?
- Alpha waves (8-12 Hz)
- Beta waves (13-30 Hz)
- Theta waves (4-7 Hz)
- Delta waves (0.5-4 Hz) (Correct answer)
Correct answer: Delta waves (0.5-4 Hz)
Slow delta waves dominate stages 3 and 4 (N3) of NREM sleep, reflecting synchronized, large-amplitude neural oscillations.
Question 3: Which pathway is responsible for transmitting fast, sharp pain signals to the brain?
- C-fibers via the spinothalamic tract
- A-delta fibers via the spinothalamic tract (Correct answer)
- A-beta fibers via the dorsal column
- Unmyelinated fibers via the spinocerebellar tract
Correct answer: A-delta fibers via the spinothalamic tract
Myelinated A-delta fibers rapidly transmit sharp, localized pain via the lateral spinothalamic tract to the thalamus and cortex.
Question 4: Epigenetics refers to changes in gene expression that occur without altering the:
- RNA transcription rate
- Protein folding structure
- Underlying DNA sequence (Correct answer)
- Ribosomal translation speed
Correct answer: Underlying DNA sequence
Epigenetic changes like DNA methylation and histone modification alter gene expression without changing the nucleotide sequence of DNA.
Question 5: Which neurotransmitter system is most directly involved in Alzheimer's disease pathology?
- Dopaminergic system
- Cholinergic system (Correct answer)
- Serotonergic system
- GABAergic system
Correct answer: Cholinergic system
Alzheimer's disease prominently involves degeneration of cholinergic neurons in the basal forebrain, especially the nucleus basalis of Meynert.
Question 6: The parietal lobe's primary somatosensory cortex contains a distorted body map known as a:
- Phrenological map
- Retinotopic map
- Homunculus (Correct answer)
- Dermatome chart
Correct answer: Homunculus
The cortical homunculus represents body parts proportionally to their sensory cortex area, so hands and lips appear disproportionately large.
Question 7: Which of the following best describes 'neuroplasticity'?
- The brain's inability to recover from injury
- The fixed genetic blueprint of neural connections
- The brain's ability to reorganize its structure and function in response to experience (Correct answer)
- The process of myelination in early childhood only
Correct answer: The brain's ability to reorganize its structure and function in response to experience
Neuroplasticity encompasses synaptic strengthening, pruning, neurogenesis, and cortical remapping in response to learning and experience.
BAPSY Biological Bases of Behavior 4
The circadian rhythm is primarily regulated by which brain structure?