Biology (Holt)

Before You Begin

is the process of taking a

gene from one organism and inserting it into

the DNA of another organism. The gene is

delivered by a ,such as a virus, or a

bacterial.

First, a fragment of a chromosome

that contains the gene is isolated by using a

,which cuts DNA at a spe-

cific nucleotide-base sequence. Some restriction

enzymes cut DNA unevenly, producing single-

stranded .The DNA of the vector is

cut by the same restriction enzyme. Next, the

chromosome fragment is mixed with the cut

DNA of the vector. Finally, an enzyme called

joins the ends of the two types of

cut DNA, producing.

In this lab, you will model genetic

engineering techniques. You will simulate

the making of recombinant DNA that

has a human gene inserted into the DNA

of a plasmid.

1.Write a definition for each boldface term

in the paragraph above and for the term

base-pairing rules.

2.Based on the objectives for this lab, write a

question you would like to explore about

the process of genetic engineering.

Procedure

PARTA: Model Genetic Engineering

1. Make 56 model nucleotides. To make
   a nucleotide, insert a pushpin midway
   along the length of a 3 cm piece of a soda
   straw. CAUTION: Handle pushpins care-
   fully. Pointed objects can cause injury.
   Push a paper clip into one end of the soda-
   straw piece until it touches the pushpin.
   2.Begin a model of a bacterial plasmid by
   arranging nucleotides for one DNA strand
   in the following order: blue, red, green, yel-
   low, red, red, blue, blue, green, red, blue,
   green, red, blue, blue, green, yellow, and
   red. Join two adjacent nucleotides by
   inserting the paper clip end of one into the
   open end of the other.
   3.Using your first DNA strand and the base-
   pairing rules, build the complementary
   strand of plasmid DNA. Note:Yellow is
   complementary to blue, and green is comple-
   mentary to red.
   4.Complete your model of a circular plasmid
   by joining the opposite ends of each DNA
   strand. Make a sketch showing the sequence
   of bases in your model plasmid. Use the
   abbreviations B, Y, G, and R for the pushpin
   colors. Your sketch should be similar to the
   one at the top of the next page.

recombinant DNA

DNA ligase

sticky ends

restriction enzyme

plasmid

vector

Genetic engineering

Exploration Lab

Modeling Recombinant DNA

SKILLS

• Modeling


• Comparing

OBJECTIVES

• Constructa model that
  can be used to explore
  the process of genetic
  engineering.


• Describehow recombinant
  DNA is made.

246 CHAPTER 11Gene Technology

MATERIALS

• paper clips (56)


• plastic soda straw
  pieces (56)


• pushpins (15 red, 15
  green, 13 blue, and
  13 yellow)

1B 2A 2C 2D 3E 6A