Biology Trivia Questions and Answers

25 questions on Biology, each with the answer and a short explanation. Part of the Science set in Rapid Fire Trivia, which holds 2,000 questions across 5 topics.

All 25 questions, with answers

1. 1What feature helps plant roots keep a plant upright?

   AnswerThey anchor it in the soil

   Branching roots grip surrounding soil while also absorbing water and dissolved minerals.

2. 2Which plant structure usually develops into a fruit after fertilization?

   AnswerOvary

   The flower’s ovary matures around seeds and becomes the fruit wall in living organisms and cells.

3. 3Which structure carries sugars from leaves to other parts of a plant?

   AnswerPhloem

   Phloem transports sucrose and other organic compounds from sources to growing or storage tissues.

4. 4Which body system includes the stomach and intestines?

   AnswerDigestive system

   The digestive system breaks food down and absorbs nutrients into the body.

5. 5Milk production for young defines which animal group?

   AnswerMammals

   Milk production by mammary glands is one of the defining traits of mammals.

6. 6Which broad group includes mushrooms, molds, and yeasts?

   AnswerFungi

   Fungi absorb nutrients from their surroundings and have cell walls containing chitin.

7. 7Bile is produced by which organ?

   AnswerLiver

   The liver makes bile, which helps break large fat droplets into smaller ones.

8. 8Which tissue inside many bones produces blood cells?

   AnswerBone marrow

   Red bone marrow generates red cells, many white cells, and platelets from stem cells.

9. 9Which animal is an amphibian?

   AnswerFrog

   Frogs typically begin life in water with gills and later develop lungs and limbs.

10. 10Why can vaccination provide long-lasting protection?

    AnswerIt creates immune memory cells

    Memory B and T cells respond faster and more strongly when the same pathogen appears again.

11. 11Which part of the eye changes size to control how much light enters?

    AnswerPupil

    Muscles in the iris alter pupil diameter according to light level during normal biological function.

12. 12Which insect is especially well known for pollinating crops and wildflowers?

    AnswerBee

    Bees transfer pollen while collecting nectar and pollen, supporting reproduction in many flowering plants.

13. 13Which bones protect the heart and lungs?

    AnswerRib cage

    Ribs and the sternum form a flexible protective enclosure around major chest organs.

14. 14Why are cactus leaves modified into spines?

    AnswerThey reduce water loss and deter animals

    Spines have little surface area, reducing transpiration while also discouraging herbivores in dry habitats.

15. 15Human fingernails are made mainly from which tough protein?

    AnswerKeratin

    Nails consist of densely packed keratinized cells produced continuously by tissue beneath the nail base.

16. 16Which flower structure produces pollen?

    AnswerAnther

    Pollen grains develop inside anthers, which sit at the tips of a flower’s stamens.

17. 17A sea star grips a surface by hydraulically extending which body structures?

    AnswerTube feet

    The water vascular system controls hundreds of tube feet used for movement, feeding, and attachment.

18. 18Which structure carries water upward through a vascular plant?

    AnswerXylem

    Xylem vessels transport water and dissolved minerals from roots toward stems and leaves.

19. 19Which body system carries hormones, nutrients, and gases through blood vessels?

    AnswerCirculatory system

    The heart and vessels distribute materials between organs while helping maintain internal conditions.

20. 20Which body part protects the brain?

    AnswerSkull

    The skull forms a hard bony case around the brain and major sensory organs.

21. 21Which trait defines mammals as a group?

    AnswerFemales produce milk for their young

    Mammary glands produce milk, a defining feature shared by all living mammal groups.

22. 22Which organ helps control blood sugar by releasing insulin?

    AnswerPancreas

    Beta cells in pancreatic islets release insulin when blood glucose rises during normal biological function.

23. 23Which carbohydrate forms much of a plant cell wall?

    AnswerCellulose

    Cellulose chains bundle into strong fibers that support plant cells and resist digestion by humans.

24. 24What part of the digestive system absorbs much of the remaining water from food waste?

    AnswerLarge intestine

    The large intestine reclaims water and salts before the remaining material becomes feces.

25. 25Which organ stores urine before it leaves the human body?

    AnswerUrinary bladder

    The muscular bladder temporarily stores urine delivered from the kidneys through the ureters.