Problem:OPTIONS:
- toxic
- natural
- artificial
- chemical

Q: What type of weathering causes the minerals in a rock to change? A:
****
A: chemical

Problem:OPTIONS:
- 14
- 25
- 30
- 20

Q: How many different amino acids make up proteins. A:
****
A: 20

Problem:OPTIONS:
- membranes
- ribosomes
- antigens
- antibodies

Q: What type of proteins bind to foreign substances and attempt destruction? A:
****
A: antibodies

Problem:OPTIONS:
- nucleus
- endothermia
- electrolysis
- meiosis

Q: During what are deletions and duplications especially likely to occur? A:
****
A:
meiosis