Explanation

• Restriction enzymes are also called molecular scissors because they cut DNA at specific recognition sequences.
• They recognize particular short DNA sequences, often 4–8 base pairs long.
• These enzymes may produce sticky ends or blunt ends after cutting DNA.
• They are widely used in genetic engineering, recombinant DNA technology, and gene cloning.
• Example: EcoRI is a restriction enzyme that recognizes the sequence GAATTC.

Last verified on 31-10-2026

Explanation

• Deamination is the process of removing the amino group (–NH₂) from amino acids.
• This process produces ammonia, which is toxic to the body.
• The liver converts ammonia into urea through the urea cycle.
• Urea is transported through the blood to the kidneys and eliminated in urine.
• The remaining carbon skeleton can be used for energy production or converted into glucose or ketone bodies.

Last verified on 31-10-2026

Explanation

• The electrical impulse originates in the SA node, the natural pacemaker of the heart.
• It takes approximately 0.03 seconds for the impulse to travel from the SA node to the AV node.
• The AV node itself produces a delay of about 0.09 seconds.
• An additional delay of approximately 0.04 seconds occurs in the penetrating part of the AV bundle (Bundle of His).
• Total delay = 0.03 + 0.09 + 0.04 = 0.16 seconds, commonly rounded to approximately 0.15 seconds.

Last verified on 31-10-2026

Explanation

• Lithonephritis refers to inflammation of the kidney associated with kidney stones.
• Kidney stones are also called renal calculi or nephroliths.
• Stones may irritate or obstruct the urinary tract, causing pain, bleeding, and sometimes infection.
• Nephritis is a general term for inflammation of the kidneys.

Last verified on 31-10-2026

Explanation