Unit 9. Human genetics and diversity

Lexis: Molecular genetics / Developmental biology / Cell biology / Anthropology Listening. 4 texts

Exercise 1. (Corresponds to exercise 7 in Book I). In the following text the lines are mixed up. Put them in the correct logical order.

Genetic Study Reveals Similarities between Diverse Populations

By Sarah Graham

a) segments of DNA that occur in specific patterns. "Each microsatellite had between four and 32

b) differences between human groups-such as skin color and skull shape-result from differences in a

с) journal Science suggests that 93 to 95 percent of human genetic variation exists among individuals

d) Marcus M. Feldman of Stanford University and his colleagues analyzed samples from 1,056 people

e) very small proportion of genetic traits."

f) variation. But the findings also reveal that even these tiny differences alone can provide enough

g) only a tiny fraction of genetic traits are distinctive to specific populations. This means that visible

h) belonging to 52 populations. Specifically, they looked at 377 so-called microsatellites, short

i) Though they may speak different languages and eat distinct foods, people from far-flung

j) within populations, while differences among major groups make up less than 5 percent of the

k) distinct types," Feldman says. "Most were found in people from several continents, suggesting that

l) geographical locations are genetically very similar, researchers say. A report published today in the

m) information to group people by population.

(From Scientific American Online, December 20, 2002)

Text a. Evolution

Exercise 2. Before listening to the text answer the following questions:

1. Who is Francis Crick and what is his contribution to molecular biology?

2. What is the central dogma of molecular biology?

3. What functions do ion channels perform in cell membranes?

4. What is RNA editing and how does it function?

ambient – окружающий, внешний to alter – изменять, переделывать

Exercise 3. Listen to the text (Script 21) to check your answers in Exercise 1. What example of RNA editing has been revealed?

Execrsie 4. Listen to the text again and answer the questions:

1. What hypothesis on gene regulation of ion channels did Dr Garrett and Ms Rosenthal have before the investigation?

2. Was it correct?

3. What is the significance of this particular investigation?

4. How does RNA editing correlate with the evolutionary theory and the central dogma of molecular biology?

Text b. The nature of man

Exercise 5. Before listening to the text answer the following questions:

1. What amount of genetic material is common between humans and other mammals?

2. What amount of genetic material is common between humans and other primates?

3. What amount of genetic material is uniquely human?

4. What functions do non-coding segments perform in the genome?

Exercse 6. What do you know about the following:

a. ENCODE project;

b. 1000 genome project;

c. purifying selection.

sleuthing – расследование telltale – указатель to be on the straight and narrow – стоять на верном пути proprietary – собственный, частный to constrain – закреплять, связывать, сдерживать cone cell – колбочка сетчатки глаза

Exercise 7. Listen to the text (Script 22) to check your answers in Exercise 5 and Exercise 6. What areas of genome were identified as «particularly human» and why? What are they responsible for?