Which of the following was a critical experimental innovation employed by Mendel that distinguished his experiments from those of his contemporaries?
Mendel performed controlled crosses with pure-breeding strains.
Many of Mendel's experiments involved crosses in which the sexes of the pure-breeding parents were switched. In each case he observed an F1 with the same phenotype. These pairs of experimental crosses are known as
In 1928, Frederick Griffith established that
heat-killed bacteria harbor the constituent(s) necessary to convey genetic properties to living bacteria
To be certain that the extract prepared from virulent cells still contained the transforming principle that was present prior to lysis, Avery
incubated nonvirulent cells with the complete extract
If Avery had observed transformation using only the extracts containing degraded DNA, degraded RNA, and degraded protein, but NOT the extract containing degraded polysaccharides, he would have concluded that
polysaccharides are the genetic material
In the early 1900s, scientists noted that chromosome movements during cell division in reproductive cells mirrored the patterns of inheritance described by Mendel. Which scientist(s) first made these observations that suggested that Mendel's hereditary units (genes) were located on chromosomes?
Walter Sutton and Theodore Boveri
Which domain(s) of life include(s) multicellular organisms?
Eukarya includes both unicellular and multicellular organisms.
Watson and Crick derived their model of DNA structure not from their own laboratory research, but rather through the analysis and interpretation of experimental data generated by others. The base-pairing rules they proposed were derived primarily from the work of whom?
What type of bonds holds the two strands of DNA together through the formation of complementary base pairs?
A-T base pairs are stabilized by two hydrogen bonds and C-G base pairs are stabilized by three hydrogen bonds.
Which of the following statements about DNA replication is NOT true?
A new DNA strand is synthesized with the same polarity (5' and 3' ends) as the template strand.A new DNA strand is synthesized antiparallel to the template strand. Therefore, the new strand has the opposite polarity of the template strand (the 5' end of the new strand is associated with the 3' end of the template strand).
The genetic code consists of a total of how many different codons?
Which of the following is not one of the four processes of evolution that lead to changes in the frequency of alleles in a population over time?
Sexual reproduction by itself does not result in changes in allele frequencies in a population over time.