Q: What replicates in the s phase of interphase, resulting in chromosomes composed of two linked sister chromatids? Choices: - protein - hormones - RNA - dna A:
dna

Q: Which reaction between alkyl halides and ammonia makes alkylamines? Choices: - nitrogen catabolism - conductive substitution reactions - nucleophobic reactions - nucleophilic substitution reactions A:
nucleophilic substitution reactions

Q: Q: What is the process whereby excess water and waste is removed from the body? Choices: - filtration - diffusion - exhalation - excretion A:
A: excretion

Question: Q: What is the most significant cause of respiratory disease as well as cardiovascular disease and cancer? Choices: - sleeping - running - driving - smoking A:
Answer: smoking

*Question*
Q: What is earth's main source of energy? Choices: - the atmosphere - the moon - the core - the sun A:
**Answer**
the sun

*Question*
Q: What term is used to describe a bond formed by the overlap of orbitals in an end-to-end fashion, with the electron density concentrated between the nuclei of the bonding atoms? Choices: - beta bond - lattice bond - rna bond - sigma bond A:
**Answer**
sigma bond