Master Cells, Genetics, Human Body Systems, Ecology & Evolution – Aligned with U.S. Science Standards
This 50 USA Biology Quiz covers cells, genetics, human body systems, ecology, evolution, and biochemistry — aligned with U.S. middle and high school science standards. Each question includes four answer choices with the correct answer provided for self-checking.
Comment your score below after tallying your correct answers. Perfect for test prep, homework review, or classroom competitions. Share this quiz with classmates to challenge each other and reinforce key biology concepts together.
Top 50 USA Biology Quiz
Results
#1. What is the main function of red blood cells?
#2. Which human body system produces hormones?
#3. What is the smallest bone in the human body?
#4. Which of these animals is a reptile?
#5. Which organ filters blood and produces urine?
#6. Which of these animals lays eggs?
#7. Which gas do animals release during respiration?
#8. Which part of the brain controls balance and coordination?
#9. What is the term for a change in DNA sequence?
#10. What type of blood vessel carries blood away from the heart?
#11. What is the term for organisms that make their own food?
#12. What is the name of the structure that connects muscles to bones?
#13. What is the process by which organisms better adapted to their environment survive and reproduce?
#14. What is the name of the process where water moves across a semipermeable membrane?
#15. What is the green pigment in plants called?
#16. Which level of organization comes after “tissue”?
#17. Which of these is a mammal?
#18. What is the name of the sugar found in DNA?
#19. Which organ pumps blood throughout the human body?
#20. Which part of the cell contains the genetic material (DNA)?
#21. What is the purpose of photosynthesis?
#22. What is the main function of white blood cells?
#23. Which type of cell does not have a nucleus?
#24. Which of these is a carnivore?
#25. Which of these is a decomposer in an ecosystem?
#26. Which vitamin is produced by the human skin when exposed to sunlight?
#27. Which organelle is responsible for protein synthesis?
#28. Which of these is responsible for blood clotting?
#29. Which organelle is known as the “powerhouse of the cell”?
#30. Which process do plants use to make food using sunlight?
#31. What is the process called when plants lose water vapor through their leaves?
#32. What is the term for an organism’s role in its ecosystem?
#33. What is the normal pH of human blood?
#34. What is the main function of the small intestine?
#35. What is the name of the double helix molecule that carries genetic information?
#36. What is the basic unit of life?
#37. Which scientist is known for his work on pea plants and heredity?
#38. What is the largest organ in the human body?
#39. What is the name of the molecule that carries energy in cells?
#40. What is the main function of the nervous system?
#41. Which of these is a vertebrate?
#42. Which human body system includes the stomach and intestines?
#43. Which system of the body is responsible for breathing?
#44. What is the name of the fluid that circulates in the heart and blood vessels?
#45. Which organelle is found only in plant cells?
#46. What is the term for a community of living organisms and their physical environment?
#47. Which scientist is known as the “Father of Evolution”?
#48. What does DNA stand for?
#49. Which of these is an example of an inherited trait?
#50. What is the process by which cells divide to produce two identical daughter cells?
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