Q: What gas comprises about three-fourths of earth's atmosphere? Choices: - hydrogen - carbon dioxide - oxygen - nitrogen A:
nitrogen

Q: In the human ear, sound waves cause the stapes to press against what? Choices: - yellow window - shaped window - Idea Window - oval window A:
oval window

Q: Q: What type of tissue transports water and minerals in a vascular plant? Choices: - collagen - capillaries - chlorophyll - xylem A:
A: xylem

Question: Q: What is the name of the protein that is found in hairs and nails? Choices: - cellulose - chromatin - Skin - keratin A:
Answer: keratin

*Question*
Q: Approximately how much larger is the radius of an atom than that of its nucleus? Choices: - 1 times - 1000 times - 100 times - 10 times A:
**Answer**
10 times

Q: Q: Fertilization is the union of a sperm and egg, resulting in the formation of what? Choices: - a cytoplasm - a nuclei - a bacteriophage - a zygote A:
A: a zygote