This document contains biology homework questions covering several topics: 1) Variation and its measurement, including questions about intraspecific variation, random sampling, normal distribution, standard deviation, and relationship between mean and standard deviation. 2) Causes of variation, including phenotype, genetic and environmental factors. 3) Measuring hand span variation through class investigations and frequency histograms. 4) DNA structure, including nucleotides, backbone, complementary strands, and Rosalind Franklin's contribution. 5) Genetics topics like gene location, genetic code, prokaryotic vs. eukaryotic DNA, meiosis, genetic diversity, founder effect, and effects of inbreeding.