Q: Sediments in oligotrophic lakes contain large amounts of what? Choices: - algae - fertilizer - igneous rocks - decomposable organic matter A:
decomposable organic matter

Q: Carbon atoms have six neutrons as well as how many protons? Choices: - ten - two - four - six A:
six

Q: Q: What is usually necessary to develop cancer? Choices: - crucial genes mutations - massive genes mutations - novel genes mutations - multiple genes mutations A:
A: multiple genes mutations

Question: Q: A stem cell is an unspecialized cell that can divide without limit as needed and can, under specific conditions, differentiate into these? Choices: - clones - infectious cells - germ cells - specialized cells A:
Answer: specialized cells

*Question*
Q: The chromosomes that have a mixture of maternal and paternal sequence are called what? Choices: - antibodies - gene - DNA - recombinant A:
**Answer**
recombinant

Q: Q: What are electrons in the outer energy level of an atom called? Choices: - shell electrons - outer electrons - positive electrons - valence electrons A:
A: valence electrons