BIO 100 EXAM 2 STUDY GUIDE LATEST UPDATE GRADED A+

BIO 100 EXAM 2 STUDY GUIDE LATEST UPDATE GRADED A+ What characteristic of DNA evidence makes it particularly valuable in criminal investigations? Its uniqueness to each individual organism. What ensures the stability of the complementary base pairs in a DNA molecule? Hydrogen bonds. Why did the double helix model of DNA generate excitement in the scientific community? It elucidated how genetic material could be duplicated through complementary strands. What are the alternative forms of most genes called? Alleles. In humans, what percentage of DNA is composed of genes? Less than 5%. Where is the highest percentage of non-coding DNA found? In eukaryotes, excluding yeasts. What does the central dogma of molecular biology describe? DNA is transcribed into RNA, which is then translated into protein. The expression of a gene to produce a polypeptide involves which two major steps? Transcription and translation. What sequence of events occurs when DNA is converted into a protein? Transcription followed by translation. In a eukaryotic cell, where do transcription and translation take place? Transcription occurs in the nucleus, while translation occurs in the cytoplasm. Define genotypes and phenotypes. Genotype: The genetic composition or allele combinations. Phenotype: The physical appearance or visible traits, determined by genotypes. What distinguishes mRNA from DNA? mRNA can travel throughout the cell, whereas DNA remains in the nucleus. Additionally, mRNA contains uracil instead of thymine, which is present in DNA. What is transcription? The process of synthesizing RNA from a DNA template. What is translation? The process of decoding an mRNA message into a protein. What are the three nonsense codons, UAA, UAG, and UGA, also known as? Stop codons. What is a frameshift mutation? A mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide. What is a point mutation? a mutation affecting only one or very few nucleotides in a gene sequence. What important factor can influence mutation rates? size of gene, nucleotide sequence, spontaneous chemical changes During the polymerase chain reaction (PCR), two strands