Study guide chapter 1 - Principles of Life
Hillis et al., Principles of Life 1e
Notes: There will be three midterms, each worth 100 points. 50 of these points will be
short answer questions, directly from the study guide questions and the associated
vocabulary. The points next to the questions give you an indication of the detail I
expect. On exams, I use the following grading scheme:



Technical term listed, correctly spelled
Concept explained, term defined
Correct example
1
2
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I have partially filled out this study guide to give you an idea of what I am looking for in
future study guides.
Read pages 1-10 (for lecture) and 10-13 (for lab). Read and bring the file Biological Key
Concepts. Make note of any questions you have about the reading. Bring those
questions to your discussion section.
0.
1.
2.
Application
What are we looking for when we
look for life on other planets? Why
are these preconceptions limiting?
Explain what led to the Indian Leaf
butterfly depicted above looking
like a dead leaf.
Image: Magic of Life Trust 2007
I.
What is life?
Biology is the scientific study of life. What does it take to be alive? What strategies
have evolved? What can go wrong? I find it useful to think in terms of challenges and
solutions.
3. What challenges does life pose (see Key Concept I)?
4
Living things (organisms) must
 Obtain nutrients and energy from environment
 Convert molecules from the environment into new biological molecules
(create order in an universe tending towards disorder (entropy)
 Respond to their environment
 Reproduce
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4.
Name some solutions to the challenge of being alive that are common to all life
forms as we know them (the common characteristics of life).
All organisms… (see remaining points in bulleted list on page 2 of Hillis)
II.
How did life and the diversity of life evolve?
5.
What is the hypothesis for the chemical evolution of life?
Briefly describe the role of nucleic acids, proteins, and
fatty acids in the evolution of life.
10
Complex biological molecules arose through random
physical associations in an energy-rich environment and
led to the appearance of self-reproducing molecules
(nucleic acids), which served as templates for stable,
large molecules (proteins), and were then protected by a
layer of fatty acids (cell membrane).
Define biological evolution, the evolution of the diversity
of life forms.
4
Genetic and resulting phenotypic change of populations
from generation to generation.
What evidence points to a common ancestry of life? 4
The similarities in gene sequences, universal genetic
code and amino acids across all organisms
Evolution is often simplified as the survival of the fittest.
Major steps in evolution were the appearance of highly
efficient eukaryotic cells (rather than prokaryotic cells)
with organelles specialized for energy transformation and
the evolution of multicellular organisms that allowed for
more sophisticated behaviors. Explain what role
cooperation plays in evolution.
8
The endosymbiosis theory postulates that chloroplasts
and mitochondria originated when a cell engulfed another
cell. Rather than one cell digesting the other, the two
cells set up a partnership and divided labor (cooperate)
between the two. Similarly, cooperation of cells in a
multicellular organisms allows more sophisticated
lifestyles and behaviors by having different cells
specializing for different tasks.
6.
7.
8.
Don't’ forget to learn
relevant vocabulary!
gene
genetic code
evolution
eukaryote
prokaryote
organelle
multicellular
species
phylogenetic tree
etc.
9.
What made it possible for life to move onto land? Be specific!
8
The accumulation of photosynthetically generated oxygen in the atmosphere
produced an ozone layer that shielded organisms on land from UV radiation.
10. Explain the evolution of different species.
8
Random changes in the genetic sequence (mutations) can give rise to structural
and functional differences between descendants of a common ancestor. These
changes, when not selected against, can accumulate in isolated populations over
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11.
12.
13.
14.
15.
time to a point were the members of these different populations can no longer
reproduce with each other.
Describe the (2) observations and (2) inferences that led Charles Darwin to his
theory of evolution by natural selection.
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Observations:
- Any population of organisms displays heritable variation.
- Only a small percentage of a population survives to reproduce.
Inferences:
- Variation leads to differential reproductive success.
- Adaptations evolve in the population.
Debunk three common misconceptions about evolution
6
a) evolution favors the fit = perfect
b) evolution states that humans descended from apes
c) evolution is driven by competition, not cooperation
Why is natural selection called a theory? See page 10 in Hillis.
4
Define genome, nucleotide, DNA, gene, and mutation (Fig. 1.5). How are these
terms connected to each other?
10
Watch the first 4 minutes of the animation on molecular evolution on YouTube
(http://www.youtube.com/watch?v=mA7BE3mEb64, accessed 1/3/12). Apply what you
learned to the phylogenetic tree in Figure 1.4.
a. Give an example for a protein common to all eukaryotes.
b. When did yeast, a fungus, and humans diverge?
c. How many differences in the gene sequence have accumulated in this time
span?
d. Why do yeast and chimps and fruit flies all use the same protein mentioned
above, even though many other proteins could fulfill the same function?
e.
Are eukarya more closely related to archaea or to bacteria? How do you
know?
10
Note: As stated above, exams consist of short answer and multiple choice questions. All
questions are derived from study guides which you’ll find for all chapters on my website at
http://fog.ccsf.edu/~cpogge. Print study guides and fill them in as you are first reading the
chapter BEFORE CLASS. Fill in the remaining answers during lecture. Study guides will
help you organize your lecture notes, focus your reading and deepen your understanding of the
concepts discussed. Understanding the answers will help you commit the ideas to your memory
and draw connections between the concepts discussed throughout the course. If you are not
sure about what a question is getting at, please ask for feedback in the discussion section.
There are multiple choice practice quizzes online at BioPortal. Ignore questions that do not
refer to study guide questions and use the practice quizzes to further commit concepts to your
memory. Most important: if you get a question wrong, analyze why you got it wrong. Did you not
study this concept? Did you misunderstand it? Or did the wording “trick” you? Please, always
feel free to ask me for clarification!
Essay question
Explain how the Indian Leaf butterfly came to look like an old leaf. Your essay should illustrate
the theory of natural selection and discuss why evolution is still controversial in the US.
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