Q: Differences between organisms reflect differences between their nucleotide sequences rather than between their what? Choices: - molecular codes - amino acids - environments - genetic codes A:
genetic codes

Q: Impenetrable what underlies the soil of the forest? Choices: - structure - topsoil - groundwater - bedrock A:
bedrock

Q: Q: As air pressures inside and outside of the ear equalize, what phenomenon is produced? Choices: - eyes blinking - throat scratching - heart skipping - ear popping A:
A: ear popping

Question: Q: What two things are used in optical instruments to reflect or refract light? Choices: - orientations and lenses - mirrors and magnifiers - prisms and microscopes - mirrors and lenses A:
Answer: mirrors and lenses

*Question*
Q: Rh antibodies can prove dangerous if they cross what barrier in pregnancy? Choices: - stomach - fungal - embryo - placental A:
**Answer**
placental

(Q).
Q: Potassium is a soft, silvery metal that ignites explosively in what? Choices: - air - cold - acid - water A:
(A).
water