A.Schevers
Chapter 15 & 17 Study Guide
1. What is a vestigial structure?
A body structure in a present day organism that no longer serves its original purpose, but was
useful in an ancestor
2. Describe how natural selection occurs?
When organism with favorable variations survive, reproduce and pass their variations to the
next generation
3. Explain how mimicry and camouflage help species survive.
Mimicry- a structural adaptation that enable one species to resemble specie
Camouflage- an adaptation that enables a species to blend with their surroundings.
4. How do homologous structures provide evidence for evolution?
Homologous structures show features with a common origin; these features can be similar in
arrangement, function or both
5. Summarize the main ideas of natural selection.
Organisms with favorable variation survive, reproduce and pass these variations to the next
generation. Organisms that do not have these variations are less likely to survivor or
reproduce. Each generation of offspring will have the variation needed for survival.
6. Explain why populations that are in genetic equilibrium are not evolving.
Allelic frequency and phenotypes stay the same
7. Compare and contrast convergent and divergent evolution.
Convergent evolution – a pattern of evolution in which distantly related organism evolve similar
traits. (Analogous structures)
Divergent evolution – pattern of evolution in which species that once were similar to an
ancestral species diverge or become increasing distinct.
8. How can geographic isolation change a population’s gene pool?
When a physical barrier divided a population. The gene pools of each population become so
different that they could no longer interbreed with the other population which results in a new
species
9. Why is rapid evolutionary change more likely to occur in small populations?
Small gene pools will see a more rapid evolutionary change
10. How do gradualism and punctuated equilibrium differ? How are they similar?
Gradualisms- species originate through a gradual change of adaptations.
Punctuated equilibrium – speciation occurs relatively quickly, with longs periods of genetic
equilibrium between, leads to rapid changes in a small gene pool.
11. What can be concluded from the observation that many organisms have the same chemical
enzymes that work in exactly the same way?
Biochemistry provides evidence for evolution. Organisms that are biochemically similar have
fewer differences in their amino acid sequences, thus these groups are more closely related, or
share a common ancestor.
12. What was the primitive Earth's atmosphere composed of?
Hyrogen, methane, ammonia, carbon dioxide, and water vapor
13. Describe directional, stabilizing, and disruptive selection. Draw a graph for each.
Stabilizing selection- favors the average individual
Directional selection- favors one of the extreme variations of a trait
Disruptive selection- favors both extreme variations of a trait
Stabilizing Selection
Directional Selection
Disruptive Selection
14. Who is the founder of modern evolution?
Charles Darwin
Chapter 17
1.
What is a scientific name, and how do you write one properly?
The genus and species name – underline both names, genus name is capitalized and the species
name is lower case
2. Why do scientists use Latin for scientific names?
It is universal and not used in conversation
3. Who devised the two-name system of classifying?
Carols Linneas
4. List the levels of biological classification.
Domain, Kingdom, Phylum, Order, Family, Genus, Species
5. List the six kingdoms.
Archebacteria, Eubacteria, Protist, Fungi, Plants, Animals
6. Describe how a cladogram classifies organisms.
It used derived traits to show phylogeny
7. Give two reasons why binomial nomenclature is useful?
Universal and makes it easy to organize
8. Which taxon contains the least number of species? Which taxon contains the largest
number of species?
9. Largest = Domian
Smallest = Species
Matching
1. Archaebacteria
2. Protista 3. Animalia 4. Eubacteria
5. Fungi 6. Plantae
1.
2.
3.
4.
5.
6.
Live in extreme environments 1
Decomposers, heterotrophs, absorbs nutrients 5
Mulitcellular consumers, man belongs to this kingdom 3
Cell walls of cellulous, oxygen producers, photosynthetic 6
Prokaryotes, found in common places 4
The catch all kingdom, very diverse, live in aquatic environments 2