With reference to a normal human being consider the following statements : I. Sugar appears in the urine if blood sugar exceeds 180 mg per 100 ml. II. Liver synthesises cholesterol and secretes it into blood. III. Blood plasma contains 92 per cent water and 8 per cent solids. IV. The total number of erythrocytes per microlitre of blood in adult male human beings averages 5-million. Which of these statements are correct?

All four statements regarding human physiology are correct. Statement I refers to the renal threshold for glucose; normally, the kidneys reabsorb all glucose, but if blood sugar exceeds approximately 180 mg/dL, the transport maximum is reached, and sugar appears in the urine (glycosuria). Statement II is accurate as the liver is the primary site for cholesterol biosynthesis, which it then packages into lipoproteins for secretion into the blood. Statement III describes blood plasma composition, which is typically 90-92% water and 8-10% solutes (proteins, electrolytes, and nutrients) [2]. Statement IV is correct as the average erythrocyte (RBC) count in a healthy adult male is approximately 5 to 5.5 million per microlitre (mm³) of blood. While the provided snippets discuss general blood transport and sugar regulation [4], these specific physiological constants are standard medical facts.

Sources

1. [2] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Activity 5.7 > p. 91
2. [1] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Artificial kidney (Hemodialysis) > p. 97
3. [3] Science , class X (NCERT 2025 ed.) > Chapter 6: Control and Coordination > Do You Know? > p. 110
4. [4] Science , class X (NCERT 2025 ed.) > Chapter 6: Control and Coordination > Do You Know? > p. 111