Frameshift mutations
a. are usually the result of damage caused by free radicals.
b. cause a change in the reading frame of mrna codons.
c. are usually caused by base analogs.
d. cause a single amino acid change in the polypeptide chain.
e. usually occur because of radiation exposure.

(select all the correct choose each statement that is scientific. - the opinions of randomly selected participants in a survey prove the idea that global temperatures are not increasing on earth. - the universe's average temperature and rate of expansion support the idea that it began as one super-dense and hot mass 13.8 billion years ago. - ocean tides are caused by the uneven gravitational pulls of the moon and sun on different parts of earth. - human life is more valuable than other forms of life on earth because humans are more intelligent than other organisms.