What does dark yellow urine indicate? 2. What is a urinometer used for?

Here are the solutions to the questions:

Question 1: Dark yellow urine sample indicates presence of:

• Bilirubinuria (presence of bilirubin in urine) causes urine to appear dark yellow to brownish.
• Urobilin is the normal pigment that gives urine its yellow color. When urine is concentrated (e.g., due to dehydration), the concentration of urobilin increases, making the urine appear darker yellow. Since both bilirubinuria and concentrated urobilin can cause a dark yellow urine sample, option (d) is the most comprehensive answer.

The correct option is d.

$$\boxed{\text{d. a and b}}$$

Question 2: Urinometer is an instrument used to measure:
A urinometer is a type of hydrometer specifically designed to measure the specific gravity of urine, which is a direct indicator of its density or concentration.

The correct option is a.

$$\boxed{\text{a. Urine density}}$$