All Free Biology MCQs with Answers

Every Biology question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.

19,844 questions · page 993 of 993

  • A. XX
  • B. XY
  • C. XO
  • D. X

Explanation: In butterflies, females typically have a ZW sex-determination system, where females are ZW and males are ZZ.

Correct answer: XY
  • A. Alports syndrome
  • B. Coffin-Lowry syndrome
  • C. Hemophilia
  • D. Thalassemia

Explanation: Option C is correct.Hemophilia is a condition that renders the individual less able to form blood clots.

Correct answer: Hemophilia
  • A. Carbohydrates
  • B. Proteins
  • C. Lipids
  • D. Vitamins

Explanation: Carbohydrates are defined as polyhydroxy aldehydes or ketones, or compounds that yield them on hydrolysis.

Correct answer: Carbohydrates
  • A. Monosaccharides
  • B. Disaccharides
  • C. Polysaccharides
  • D. None of these

Explanation: Sucrose is a disaccharide: one glucose unit joined to one fructose unit by a glycosidic bond, with the loss of a molecule of water.

Correct answer: Disaccharides