STRUCTURE of DNA (Worksheet #3; Module 5)
These exercises help to “cement” the information in our brain so we can use that learning in our other tasks, both in life and in this course.

Goal of this activity
• To work with the structure of DNA
Steps for Success with this activity
1. Look through the entire document, making note of what you have seen or heard previously. Rely on your prior learning! Use that learning to build more.
2. Work hard before you consult the answer page! Healthy frustration is the foundation of real learning, so let yourself be in a bit a “quandary” before you check your answers.
3. Bring all questions and inconsistencies to the Tech Live sessions.

TOPICS and ACTIVITIES
A. Distinguish between chromosomes, genes, and traits (OpenStax, Concepts of Biology, section 2.1)
1. Review the definitions:
a) Chromosomes =
b) Genes =
c) Traits =
2. Draw a chromosome, then show where a gene might lay:

B. Describe the structure of DNA and how it is replicated, repaired, and protected (OpenStax, section 9.1)
1. STRUCTURE of DNA (OpenStax, figure 9.4) Draw the double helix with the following labels:
a) Sugar phosphate backbone
b) Base pair
c) A = adenine
d) T = thymine
e) C = cytosine
f) G = guanine
g) 5’ end
h) 3’ end

BIO 1000 – Module 5 Worksheet #3, page 2

2. REPLICATION of DNA (OpenStax, section 9.2)
a) Before each cell division, our DNA must be copied accurately and completely. This process is done by a “Polymerase”.
b) Draw the new strands that are created from the old strands: (see Figure 9.9)

Application questions:
 What happens to the genome if the replication is not accurate or complete?
 What disease might result?

3. PROTECTION of DNA – What is the “end” of each eukaryotic chromosome called?
(see Figure 9.11) When is this part of the chromosome replaced?

Application questions:
 What happens to the genome if the “ends” of the chromosomes were not protected?
 What disease might result?

C. Compare the structure of DNA in eukaryotic and prokaryotic cells (OpenStax, Figure 9.6)
1. While the structure of DNA is the same in plants, animals, bacteria, fungi and protists, the size and packaging is different between eukaryotes and prokaryotes.
2. Complete the table to compare the structure of DNA between eukaryotes and prokaryotes:

PROPERTY (Characteristic) PROKARYOTES EUKARYOTES
Size of the genome
(approximate)
Location of the genome
(in the cell)
Structure
(linear or circular)
Packaging
(in order to fit in the cell)

D. Explain the Central Dogma (OpenStax, section 9.3)

1. Map the Central Dogma

2. Name the process at each arrow: 1 = ; 2 =