BSCI 222 Study Guide - Midterm Guide: Base Pair, Transposable Element, Cytosine
Document Summary
Gss worksheet: draw an accurate depiction of a 3-nucleotide dna strand, while identifying each major component as well as the 5" and 3" ends. The three major components are the phosphate group, the deoxyribose sugar, and the nitrogenous base. Rna has a ribose sugar instead of a deoxyribose sugar i. e. it has a hydroxyl (oh) group on the 2" carbon instead of hydrogen. Since this is a 50bp ds-dna molecule, there are 100 nucleotides total. That means that there are 15 adenine nucleotides, and 15 thymine nucleotides as well. That means there are 35 guanine and 35 cytosine nucleotides by consequence. Since pyrimidines consist of thymine and cytosine, there are. 35+15 = 50 pyrimidines in this dna molecule. Euchromatin corresponds to chromosomal regions that are diffuse during interphase and condensed at the time of nuclear division. These regions are the most active during gene expression (i. e. transcription). However, heterochromatin remains condensed during the entire cell cycle and is poorly expressed.