Transcript ppt with answers

AP Biology
Saturday Session 3
Evolution as a Process
Session 3 – Change over Time
Question 1
C
Clue: clear-cutting &
enhanced
Succession
(Mount St. Helens, WA)
Stages of Succession
Pioneer stage, with fireweed dominant
Dryas stage
60
Soil nitrogen (g/m2)
50
40
30
20
10
0
Pioneer
Dryas
Alder Spruce
Successional stage
Nitrogen fixation by Dryas and alder
increases the soil nitrogen content.
Spruce
stage
Possible source of secondary succession
(Forest fire destroys the forest)
Primary Succession
(Remember Hawaii?)
Primary Succession
(Pioneer species)
Primary Succession
Primary succession
Primary Succession
Climax Community (Hawaii today)
Question 2
A
Clue: shallower =
more recent
Fossil Formation using water,
sediment, and long periods of time
Question 3
C
Stanley Miller and
Harold Urey
experimental set up
CH4
Water vapor
Electrode
Condenser
Cold
water
H2 O
Cooled water
containing
organic
molecules
Sample for
chemical analysis
Question 4
D
DNA Chromosomes
mRNA from DNA
Question 5
B
Clue: took advantage
Question 6
A
Math Grid In solution
• Step 1: 100% ÷ 8 = 12.5%
• Step 2: Time 0
= 100% = 0 years
First Half life = 50% = 5,730 years
Second Half life = 25% = 5,730 years
Third Half life = 12.5% = 5,730 years
Adds up to: 17,190 years
Short Free Response 1
4 points possible
Possible points awarded for:
Discussion of the Endosymbiotic Hypothesis
proposing a method for eukaryotic cells to
evolve, over time, from prokaryotic cells that
formed symbiotic relationships. (1 pt.)
3 Possible facts : Each possesses its own DNA
1 pt. each
Reproduces by binnary fission
Each has its own ribosomes
Each can generate energy.
Short Free Response 2
4 points possible
Discussion of amino acids needed to make proteins
(work horse molecules) and nucleic acids storing
information. (1 pt.)
Discussion of using environments energy to make larger
complex molecules for building structures. (1 pt.)
Discussion of RNA/DNA being used for reproduction
and information storage. (1 pt.)
Discussion of membranes needed to hold cell together
and form a separate internal space. (1 pt.)