| Each DNA nucleotide is composed of ____ | a five-carbon sugar, a phosphate group, and one of four nitrogenous bases |
| Which statement describes a difference between meiosis I and meiosis II? | Homologous chromosomes separate during meiosis I; sister chromatids separate during meiosis II. |
| The genome of an organism contains 14% guanine; therefore, its genome also contains ____% thymine and ____% cytosine. | 36; 14 |
| Suppose a DNA replication error is not corrected. After two cell divisions, how many of the four daughter cells contain this mutation (assuming that the mistake was never corrected)? | four |
| Homologous chromosomes ____ | contain a maternal and paternal chromosome |
| After the first meiotic division, the two daughter cells ____ | have half the diploid number of chromosomes |
| How are purines distinguished from pyrimidines? | Purines are derived from a pair of fused C-N rings, while pyrimidines are derived from a single C-N ring. |
| Before anaphase II, the sister chromatids form a single chromosome; after anaphase II, each sister chromatid is an individual chromosome. | What is the difference between sister chromatids before and after anaphase II? |
| Adding nucleotides onto a growing DNA strand during DNA replication in cells occurs in ____ | the 5' → 3' direction only |
| The transforming principle described by Griffith in his work with Streptococcus pneumoniae is ____ | DNA |
| When Hershey and Chase labeled viruses with radioactive phosphorus, they concluded that the virus injects DNA and not protein into its host because ____ | most of the radioactive DNA was inside the bacteria |
| Nondisjunction during meiosis I results in ____. | one pole of the cell receiving neither member of a homologous pair of chromosomes |
| Suppose that you performed a version of the Hershey and Chase experiment, this time using 32P-labeled viruses that insert their double-stranded DNA into the DNA of the cells that they infect. The viral DNA is then treated as part of the cell's own DNA and is replicated during DNA replication and passed onto daughter cells when the cell divides. You infect a population of cells with the 32P-labeled viruses, and then let the infected cells go through two generations of cell divisions. If you then examine the cells, you should find 32P-labeled DNA in ____ of the cells. | about 1/2 |
| Telophase | mitotic spindle disassembles |
| Prophase | Duplicated chromosomes condense |
| Metaphase | chromosomes align at the center of the cell |
| Anaphase | sister chromatids are pulled to opposite spindle poles |
| Prophase | RNA synthesis shuts down |
| Telophase | daughter chromosomes decondense and the nuclear envelope reforms |
| Prometaphase | nuclear envelope disappears |
| Prophase (also) | spindle fiber begins to form |
| Which statement describes a similarity between meiosis and mitosis? | DNA is replicated only once in both processes |
| The daughter cells produced by meiosis are ____ | genetically different from the parent and each other |
| A DNA double helix has two strands that are held together by ____ | hydrogen bonds |
| During which phase(s) of mitosis are chromosomes composed of two sister chromatids? | prophase, prometaphase, and metaphase |
| Sexual reproduction has an advantage over asexual reproduction by ____ | creating more genetic diversity |
| Homologous chromosomes undergo recombination during ____ | prophase I |
| In their experiments to identify the transforming principle, Avery, MacLeod, and McCarty used enzymes that break down ____ | protein, DNA, and RNA |
| What happens when living R strain Streptococcus pneumoniae bacteria are mixed with heat-killed S strain Streptococcus pneumoniae bacteria? | The R strain bacteria are transformed into S strain bacteria. |
| Which nucleotide sequence is complementary to the DNA sequence 5'-GACGTT-3'? | 3'-CTGCAA-5' |
| Figure 14.1 The figure above depicts the result of an experiment to determine how DNA replication occurs. Based on these results, it appears that after replication, each new DNA molecule contains ____. | one old DNA strand and one new DNA strand |
| Hershey and Chase | Showed that the genetic material of bacteriophage T2 is DNA |
| Watson and Crick | Worked out the double helix model for DNA structure |
| Meselson and Stahl | Showed that DNA replication in Escherichia coli is semiconservative |
| Avery, MacLeod, and McCarty | Showed that DNA is the transforming principle responsible for transforming nonvirulent Streptococcus pneumoniae into a virulent strain |
| Griffith | Showed that a transforming principle from heat-killed S strain Streptococcus pneumoniae could be used to make the R strain virulent |
