Marfan syndrome in humans is caused by an abnormality of the connective tissue protein fibrillin. Patients are usually very tall and thin, with long spindly fingers, curvature of the spine, sometimes weakened arterial walls, and sometimes eye problems, such as lens dislocation. Which of the following would you conclude about Marfan syndrome from this information?  

A sample of double-stranded DNA contains 42% cytosine. Approximately what percent of the nucleotides in this sample will be thymine?  

A student isolates, purifies, and combines in a test tube a variety of molecules needed for DNA replication. When she adds some DNA to the mixture, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture?  

During which of the following processes do homologous pairs of chromosomes align adjacent to one another at the metaphase plate of a cell?  

Which component is directly involved in translation?  

Which of the following changes in an exon is most likely to result in a nonfunctional protein product?  

During which of the following phases of meiosis do centromeres split and sister chromatids migrate to opposite poles of the cell?  

Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I?  

Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal?  

Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Which of the following statements best represents the connection between reproduction and evolution?