新视野大学英语读写教程（第二版）第四册 Unit 7 Section A Research into Population Genetics.pptx

;Lead-in;Lead - in;Q. 1 What’s your definition of population genetics?;Q. 2 What’s the origin of population genetics?;Q. 3 What major factors usually lead to genetic changes?;Pre-Reading;Background Information;Background Information;;Background Information; Our bodies are comprised of trillions of microscopic units called cells. Cells in turn are built up from many specific types of molecules, both large and small. The large molecules or macromolecules include polysaccharides, nucleic acids and proteins. Proteins are the workhorses of our cells. The flow of genetic information is from DNA to RNA to Protein. ;Background Information;;Compound Dictation; Small genetic differences make one person different from another. Now medical researchers have a new map to help them find these differences. More than two hundred scientists from six nations developed the HapMap. The name comes from the word haplotype. A haplotype is a group of differences that are likely to [S1] ______ close together in a block. These blocks [S2] _______ to pass from parent to child. ; The HapMap scientists hope to identify up to six million DNA differences before they finish. The HapMap Project developed from information provided by the Human [S3] ________ Project. That project was [S4] _________ in two thousand three. It identified all the chemical pieces in DNA, the genetic material in cells. DNA has more than three thousand million building blocks. A [S5] ______ of these building blocks forms a gene. ; For any two people, the building blocks are almost all the same. But [S6] _________ small differences can mean that one person has a higher risk of disease. One kind of difference is called a SNP [pronounced snip]. There are millions of places where SNPs can happen. The HapMap Project is identifying common places where they are found. ; Studying haplotype blocks will make it easier to find the genes [S7] _________ of causing a disease. The researchers may b