TAKS Warm Up
Remember to write this on the first
free left page of your notebook.
Write the answer and your reasoning
for your choice only!!!
TAKS Question #1
Part of a DNA molecule is
represented by the model to the
right. In order for DNA to
replicate, the strand must
separate at which of the
A. Between every phosphate sugar
B. Between the eight sugar base
C. Between the four nitrogenous
D. Between any two chemical
TAKS Question #2
The model shows a demonstration a
student prepared using black
and white marbles to show how
populations of organisms can
change. Which of the following
concepts is best illustrated by
A. Evolution of a predatory species.
B. Genetic drift accompanying
C. Environmentally induced genetic
D. Immunity from virulent
Purpose: Students will examine hardware
devices to simulate how common ancestry and
biochemical evidence are used to determine
Materials: Wooden peg, brass tack, 2” nail, 3”
nail, bolt, screw, Molly screw, metric ruler.
Safety: The tacks, nails, bolt, and screws
should not be used in an inappropriate
Types of Screws
1. Record the names of the hardware pieces and your
observations for each in Data Table.
1. Observe as many anatomical (physical structure) characteristics
• Composition: the way in which something is made, especially in terms
of its different parts.
• Length: distance from end to end.
• Number of threads present: the number of helical ridges on a screw.
• Thread diameter: What is the diameter (width) of the thread?
• Head type:
• Head size: what is the diameter of the head of the screw?
• Other: Color? Pointy or flat? And anything else you can think of.
Data Table 1
Characteristics WP Brass 2” nail 3” nail Bolt Screw Molly Screw
# Threads present
Use the information from Data Table 1 to complete the
Begin by listing the wooden peg as the most closely
related hardware device to the Common Ancestor.
Then add the next hardware device that is the most
closely related to the wooden peg according to the
information in Data Table 1.
Continue this process for numbers 3 to 7.
Remember: according to cladistics, the greater the
number of characteristics shared by two organisms
(screws), the more closely related they are with regard to
The following DNA sequences were obtained
for each of the hardware devices.
Compare pairs of hardware devices, count
any differences, and record that number in
Data Table 2.
Be sure to compare the DNA sequences by
triplets, or codons.
For example, CTT to GCT which would count
only as one difference.
Wooden peg vs. Brass tack
• AGG CAT AAA CCA ACC GAT TAC
• AGG CAT ATT CCA ACC GAT TAC
Wooden Brass tack 2” nail 3” nail Bolt Screw Molly
Wooden 0 1
Brass tack 1 0
2” nail 0
3” nail 0
4. Use the information recorded in Data Table 2
to infer the evolutionary relationships among
the various hardware devices. For example,
the DNA sequence of the wooden peg and
brass tack indicate they are closely related. To
what extent do the DNA sequences above
support the information in your cladogram? Do
you need to revise your cladogram? Why or
On the backside of your
Create a vocabulary card for each of the
• Cladogram: a tree-shaped diagram showing
evolutionary relationships and the points where
species appear to have diverged from common
• Natural selection: the process, according to Darwin, by
which organisms are best suited to survival in their
environment achieve greater reproductive success
and thereby passing advantageous genetic traits to
Definition. Definition in your
Draw a picture to Draw a picture to represent the
represent the word. opposite.