DNA Interactive \ worksheet Directions: Answer the questions on this worksheet. Complete each section by following the
instructions on the first page.
DNA EXTRACTION
1. What are three reasons why we would need to extract DNA?
2. Why does the DNA need to be extracted from a cell before it can be analyzed?
3. About how much DNA is inside every cell’s nucleus?
4. When we extracted our own DNA last Friday, how did the things we used (Gatorade, alcohol,
soap) relate to the things that are used in this virtual lab?
5. What are the alcohol and soap used for?

GEL ELECTROPHORESIS
1. What is electrophoresis used for?
2. Why is “gel” used?
3. What makes the DNA move?
4. Which strands move father? Why do you think they are able to do this?
5. What is a buffer? Why is it used in electrophoresis?
6. Why it is important to put the black (negative) cord closest to the wells where the negatively
charged DNA was injected?

TRANSCRIPTION & TRANSLATION
1. Why do you think it is important for there to be designated “Start” and “Stop” codons?
2. What amino acid would you end up with if you replaced the U in the second reading frame with
a G?
3. What amino acid would you end up if you deleted the C from the second reading frame?
4. What amino acid would you end up with if you added a G to the end of the second reading
frame?
5. How might having a mutation occur during transcription harm an organism? How might an
organism benefit from this?

ucd e e. rr. t t t t t t. to

the african cheetah.

this species has a relatively low level of genetic

variation because the population was reduced to a small size approxi-

mately 10,000 to 12,000 years ago.

chapter   outline

24.1

genes in populations and the hardy-

weinberg equation

24.2

factors that change allele and genotype

frequencies in populations

24.3     sources of new genetic variation

population   genetics

24

until   now,   we   have   primarily   focused   our   attention   on   genes  

within   individuals   and   their   related   family   members.   in   this  

chapter   and   chapters   25   and   26   ,   we   turn   to   the   study   of   genes   in  

a   population   or   species.   the   field   of

population   genetics

  is   con-

cerned   with   changes   in   genetic   variation   within   a   group   of   indi-

viduals   over   time.   population   geneticists   want   to   know   the   extent  

of   genetic   variation   within   populations,   why   it   exists,   and   how   it  

changes   over   the   course   of   many   generations.   the   field   of   popu-

lation   genetics   emerged   as   a   branch   of   genetics   in   the   1920s   and  

1930s.   its   mathematical   foundations   were   developed   by   theoreti-

cians   who   extended   the   principles   of   gregor   mendel   and   charles  

darwin   by   deriving   formulas   to   explain   the   occurrence   of   geno-

types   within   populations.   these   foundations   can   be   largely   attrib-

uted to three scientists: sir ronald fisher, sewall wright, and j. b. s.

haldane.   as   we   will   see,   support   for   their   mathematical   theories  

was provided by several researchers who analyzed the genetic com-

position   of   natural   and   experimental   populations.   more   recently,  

population   geneticists   have   used   techniques   to   probe   genetic  

variation   at   the   molecular   level.   in   addition,   staggering   advances  

in   computer   technology   have   aided   population   geneticists   in   the  

analysis   of   their   genetic   theories   and   data.   in   this   chapter,   we   will  

explore   the   genetic   variation   that   occurs   in   populations   and   con-

sider   the   reasons   why   the   genetic   composition   of   populations   may  

change over the course of several generations

1. what is the relationship between the shape of an enzyme and the reactions they catalyze?

2. how does an enzyme inhibitor work?

separate your answers so i dont get confused : )