Consider statements about the endoplasmic reticulum: 1. Rough ER has ribosomes attached. 2. Smooth ER synthesizes lipids. 3. Rough ER is involved in detoxification. Which are correct? MCQ with Answer and Explanation

Explanation:
Lysosomes are membrane-bound vesicles budded off from the Golgi apparatus. They contain powerful hydrolytic enzymes capable of breaking down proteins, lipids, and nucleic acids. They play a crucial role in autophagy, digesting worn-out cellular organelles. Thus, all three statements are biologically accurate and correct.

Explanation:
The Reticular Activating System (RAS), or Ascending Reticular Activating System (ARAS), is a complex network of neurons located in the core of the brainstem (spanning the medulla, pons, and midbrain). It projects diffusely to the thalamus and cerebral cortex. Its primary function is to regulate the overall level of arousal, consciousness, and wakefulness of the brain. It filters incoming sensory information, allowing important stimuli to reach conscious awareness, and plays a crucial role in the sleep-wake cycle and transitions between sleep stages.

Explanation:
Immunoglobulin G (IgG) is the most abundant antibody in blood plasma, providing long-term immunity and crossing the placenta. Immunoglobulin E (IgE) is present in small amounts and binds to mast cells, triggering the release of histamine during allergic reactions. Immunoglobulin A (IgA) is predominantly found in mucosal secretions like saliva, tears, and breast milk, providing localized mucosal immunity. All statements are correct.