Q: What does the base of a nucleotide within dna consist of? Choices: - ribosomes - protein - hydrogen - nitrogen A:
nitrogen

Q: Red litmus paper turns what color when placed in a basic solution? Choices: - white - orange - pink - blue A:
blue

Q: Q: Where do carrier proteins carry ions or molecules? Choices: - between nuclei - across isotopes - back to nucleus - across the membrane A:
A: across the membrane

Question: Q: What forms the changing shapes of sand dunes? Choices: - temperature - humidity - magnetism - wind A:
Answer: wind

*Question*
Q: What is often the cause of phenotypic differences between identical twins? Choices: - natural selection - genetics - learned behavior - environment A:
**Answer**
environment

*Question*
Q: In the lungs, oxygen diffuses out of the alveoli and into where? Choices: - blood - neurons - cillia - capillaries A:
**Answer**
capillaries