Master NEET Zoology with topic-wise questions. Tailored for NEET students, these questions strengthen your Biology preparation.
Which of the following drugs acts as a depressant by enhancing the inhibitory effects of GABA, but DOES NOT directly bind to the GABA receptor site like benzodiazepines?
Barbiturates
Benzodiazepines
Alcohol
Cannabis
A patient presents with pinpoint pupils, depressed respiration, and slurred speech. Toxicological screening reveals the presence of opioids. Which of the following is the MOST likely cause of these symptoms, and what is the immediate treatment of choice?
Cocaine overdose; Activated charcoal
Cannabis overdose; Supportive care
Heroin overdose; Naloxone
Alcohol withdrawal; Diazepam
Which pathway in the brain is MOST strongly associated with the rewarding effects of drugs of abuse, and which neurotransmitter plays a central role in this pathway?
Nigrostriatal pathway; Dopamine
Mesolimbic pathway; Dopamine
Tuberoinfundibular pathway; Dopamine
Corticospinal tract; Acetylcholine
Chronic cocaine use can lead to downregulation of which specific dopamine receptors, contributing to the development of tolerance and withdrawal symptoms?
D1 receptors
D2 receptors
D3 receptors
D4 receptors
A patient experiencing alcohol withdrawal exhibits tremors, anxiety, and insomnia. Which drug is MOST likely to be prescribed to manage these symptoms, and what is its mechanism of action?
Naltrexone; Opioid receptor antagonist
Disulfiram; Inhibiting aldehyde dehydrogenase
Benzodiazepines; Enhancing GABAergic neurotransmission
Methadone; Opioid receptor agonist
A patient presents with severe allergic symptoms after consuming peanuts. Which of the following is the LEAST likely mechanism contributing to their reaction?
Mast cell degranulation and release of histamine and other mediators.
Cross-linking of IgE antibodies bound to mast cells by peanut allergens.
Increased production of IgG antibodies specific to peanut allergens.
Activation of the complement system via the classical pathway.
Which of the following is NOT a typical characteristic of allergens that contributes to their ability to elicit an IgE-mediated immune response?
Low molecular weight, typically less than 50 kDa.
High solubility and stability.
Presence of glycosylation or other post-translational modifications.
High molecular weight, typically greater than 500 kDa.
A patient experiences an allergic reaction after being stung by a bee. Which of the following cell types is NOT directly involved in the immediate hypersensitivity response?
Mast cells
Basophils
Eosinophils
Cytotoxic T lymphocytes (CTLs)
The 'hygiene hypothesis' proposes that reduced exposure to certain pathogens in early childhood may contribute to the development of allergies. Which of the following is NOT a plausible mechanism supporting this hypothesis?
Skewing of the immune system towards a Th2-dominant response.
Reduced development of Th1 responses that normally counterbalance Th2 activity.
Lack of appropriate stimulation for the development of immune tolerance.
Enhanced development of regulatory T cells (Tregs) that suppress Th2 responses.
Which statement regarding the genetic predisposition to allergies is MOST accurate?
A single gene mutation is usually responsible for most allergic conditions.
Genetic factors play a minimal role in the development of allergies; environmental factors are primarily responsible.
Allergies are strictly inherited following Mendelian patterns of inheritance.
Multiple genes interacting with environmental factors contribute to the development of allergies.
