*Question*
If many corals secrete a hard outer covering that builds up to become a coral reef, then many corals secrete what to form a coral reef? Answer choices: - Chlorophyll - salt and water. - The area was once underwater - Chemical energy - aqueous solution - Organic compounds - gastropod shells - hard outer covering
**Answer**
hard outer covering

*Question*
If amutation in parent's sex cells can cause new traits to appear in a child, then amutation in parent's sex cells can cause new traits to appear in a what? Answer choices: - concern - pet - parent - germs - haploid - gametes - DNA - child
**Answer**
child

*Question*
If arthropods are the largest phylum of animals without a backbone, then what are arthropods the largest phylum of? Answer choices: - Something to move - animals without a backbone - Earth orbiting the Sun - microorganisms - absorb light energy - converting mass to energy - Generating heat - remains of prehistoric life
**Answer**
animals without a backbone

*Question*
If viruses can infect good and bad types, then how many types can viruses infect? Answer choices: - mice - pigs - bird - RNA - ova - tiny - HPV - Two
**Answer**
Two