BSC 1005 Exam 2 - Questions and Answers

BSC 1005 Exam 2 - Questions and Answers DNA has the capacity to store genetic information, copy it, and pass it from one generation to the other generation. Chromatin is DNA and proteins Nucleic acids DNA and RNA; consist of long chains of nucleotides. Therefore nucleotides are monomers and nucleic acids are polymers. DNA is double stranded while RNA is single stranded. Each nucleotide consists of 3 main parts; a nitrogenous base with a purine or pyrimidine, a pentose sugar with 5 carbon atoms, and a phosphate group consisting of 1, 2, or 3 phosphate groups attached to the carbon atom. Purines Adenine and Guanine Pyrimidines Cytosine and Thymine Purines and Pyrimidines are connected by a hydrogen bond. Adenine is to _ as Cytosine is to _. Thymine; Guanine In RNA, Thymine is replaced by Uracil. It is the order of these bases in a nucleic acid that specifies genetic information. Small hydroxyl groups hang from the sugar portion of the nucleotide. DNAs have one less O (H & OH), hence the name Deoxy ribose, than RNA. RNA has two OH groups. In cells, each DNA molecule is organized as a chromosome. A chromosome consists of DNA and associated proteins, carries a cell' s genetic info. Genome (chromatin) entire DNA center of the cell. Rungs of DNA are made of nitrogen bases connected by hydrogen bonds. James Watson and Francis Crick won the Nobel prize for their 3D double helix model of DNA molecule. DNA contains anti-parallel strands; oriented but in different directions. Hydrogen bond sticks strands together and breaks when replicating. Role of enzymes: DNA polymerase adds new nucleotides to new strand. To proofread pairs are correctly matched uses ATP. DNA ligase participates in DNA repairs, fills in tiny gaps. Reproductive cloning Results in an exact genetic copy of an adult individual. Therapeutic cloning Cloned human embryos used in making stem cells that are used in research. Human genome project The determination of the complete nucleotide sequence of DNA of each human chromosome. Cell reproduction living cells dividing. Diploid cell made up of two sets of 23 chromosomes each.