Biology Now, 2e

166 ■ CHAPTER 09 What Genes Are GENETICS however, changing a few nucleotides in a gene’s DNA sequence has little or no effect. I ...

Pigs to the Rescue ■ 167 Human stem cells are obtained from the transplant patient. The guide RNA finds the target^3 DNA sequenc ...

The genome editing tool CRISPR, short for “clustered regularly interspaced short palindromic repeats,” has taken molecular biolo ...

Pigs to the Rescue ■ 169 REVIEWING THE SCIENCE ● (^) Genes are composed of DNA, which consists of two parallel strands of repeat ...

170 ■ CHAPTER 09 What Genes Are (^7) Select the correct terms: To work on removing PERV DNA from the pig genome, researchers fir ...

Pigs to the Rescue ■ 171 controlling gene expression. Some of it has architectural functions, such as giving structure to chromo ...

Tobacco’s New Leaf One company’s quest to produce tomorrow’s drugs in today’s plants. ◆ (^) Explain how an organism uses gene ex ...

173 GENETICS 10 CHAPTER HOW GENES WORK ...

174 ■ CHAPTER 10 How Genes Work GENETICS T he greenhouse is vast, the size of half a football field. A loud, steady thrum rever- ...

Tobacco’s New Leaf ■ 175 Tobacco Egg Speed from outbreak to vaccine production: 1 month 6 months Cost to produce 50 million flu ...

176 ■ CHAPTER 10 How Genes Work GENETICS contrast, Medicago produced its vaccine, ready for testing, in just 19 days. To make a ...

Tobacco’s New Leaf ■ 177 Outbreak! Samples of the flu virus are taken from sick people and sent to medical labs to be sequenced. ...

178 ■ CHAPTER 10 How Genes Work GENETICS Once bound to the promoter, the RNA polymerase unzips the DNA double helix at the begin ...

Tobacco’s New Leaf ■ 179 Two-Step Dance, Translation: RNA to Protein The microscopic molecular dance inside the tobacco cells co ...

180 ■ CHAPTER 10 How Genes Work GENETICS G U G A G U C CC A GG UAC Methionine Methionine Ribosome Covalent bond Start codon Star ...

Tobacco’s New Leaf ■ 181 specifies only one amino acid. It is also redun- dant: since there are a total of 64 codons but only 20 ...

182 ■ CHAPTER 10 How Genes Work GENETICS First letter of codon Third letter of codon Second letter of codon The genetic code Phe ...

Tobacco’s New Leaf ■ 183 among other possibilities. While single-base substitutions are not always a problem, single- base inser ...

184 ■ CHAPTER 10 How Genes Work GENETICS Gene Nucleus Cytoplasm Broken-down mRNA Broken-down protein Protein mRNA mRNA Control p ...

The Deadly Price of a Pandemic The Spanish flu of 1918 devastated populations across Europe, killing not only the young and old, ...