Download Biology Unit 6 Review Guide ANSWERS

BIOLOGY – Mr. Channell
NAME: _______________________
Biology Unit 6 Review Guide ANSWERS
Complete on a separate sheet of paper if needed.
1. List the types of evidence used to classify organisms and explain each one.
Morphology (physical structures) and DNA sequencing
2. Identify the 6 kingdoms living things are divided into.
Archaebacteria, Eubacteria, Protista, Fungi, Plantae, Animalia
3. Explain the key features of each kingdom (uni/multicellular, pro/eukaryote,
auto/hetertroph, etc.).
Archaebacteria – prokaryote, unicellular, auto or heterotroph, cell wall
Eubactera – prokaryote, unicellular, auto or heterotroph, cell wall
Protista – eukaryote, uni or multicellular, auto or heterotroph
Fungi – eukaryote, mostly multicellular, heterotroph, cell wall
Plantae – eukaryote, multicellular, autotroph, cell wall
Animalia – eukaryote, multicellular, heterotroph
4. Write the taxons in order from most general to most specific.
Kingdom, phylum, class, order, family, genus, species
5. Explain how to write a proper scientific name and write the one for humans as an
example.
Genus followed by species…only genus name is capitalized…written in either
italics or underlined (EX: Homo sapiens or Homo sapiens)
6. Define the term “species”.
Group capable of making fertile offspring
7. Define the term “theory” (as used in science).
Seeks to explain an event but cannot be proven correct
8. Define the term “evolution”.
A gradual change in the characteristics of a population over successive
generations
9. Why is wrong to say, “evolution is just a theory”, meaning that one thinks it is
less important or supported than other scientific concepts?
Evolution is a theory supported by a very large amount of facts, data, and
observations, meaning it is much more than just an “guess”.
10. Write the 4 parts of natural selection and explain what occurs in each.
Successful reproduction – variations in individuals help or hinder
reproduction, and the best adapted individuals reproduce to pass on
favorable traits
Struggle to survive – competition for resources to live and reproduce
(“survival of the fittest” aka best adapted)
Inherited variation – genetic variation increases a species’ chance to survive
environmental change
Overproduction – regulation of reproduction to control amount of offspring
that can survive
11. What is the main process that causes evolution?
Natural selection.
12. Explain why, over long periods of time, populations of organisms become wellsuited to their environment.
The individuals that have favorable traits for their environment outcompete
those that are not as well suited. This allows the better suited individuals to
pass their favorable traits on to their offspring (and, potentially, produce
more offspring in their lifetime). Over successive generations, the proportion
of individuals in the population that carry favorable traits outweigh the
proportion of individuals with that carry less favorable traits.
13. Explain why sexual reproduction is an evolutionary advantage.
Sexual reproduction involves a mixture of DNA from 2 parents, increasing
genetic diversity.
14. Explain why genetic diversity within an ecosystem is important to the long-term
survival of organisms.
Genetic diversity gives a species a better chance to survive extreme
environmental change. This change can be in the form of things like
cataclysmic events or epidemic disease. The variation of traits helps ensure
that at least a portion of the population will survive these events.
15. What is the smallest group that can evolve?
A population within the same species is the small group that can evolve.
16. What is “speciation”?
Process by which new species arise.
17. What does “fitness” mean in terms of evolution?
Fitness is how well adapted, in terms of physical and/or genetic traits, an
individual is to survive and reproduce in their environment.
18. What is geographic isolation? Reproductive isolation? Why are they important to
speciation?
Geographic isolation occurs when populations are physically separated from
one another (EX: “continental drift” of Pangea).
Reproductive isolation occurs when organisms are sexually isolated by not
attracting a mate (EX: lack of functioning anatomy, pheromones, or mating
rituals).
These are important as they can trigger new species arising.
19. How does a new species originate?
This occurs when 2 populations of a species have been separated long enough
that they can no longer interbreed.
20. Why are genetic mutations important for the survival of a species?
Genetic diversity allow species’ to differentiate their physical and genetic
traits, thus giving a better chance to cope with changes in the environment.
21. Explain how a genetic mutation will effect an organism.
A genetic mutation can be helpful, harmful, or have no effect at all.
22. Define the term “gene pool”.
A gene pool is a collection of all of the genes that can be shared/mixed within
a population of a species.
23. How would extinction affect a gene pool?
The extinction of a population of a species would affect the proportional
amounts of the types of genes within the gene pool. The extinct populations’
genes would no longer be circulated through reproduction.
24. Give an example of how genetic variation and environmental factors can result in
evolution.
An example of genetic variation and environmental factors resulting in
evolution would be if a population of a species changed environments, say,
from land to water. Beneficial mutations that allowed organisms to better
compete in the new environment (webbed toes, for example) would allow for
better competition for resources and increase the prevalence of those traits
over many successive generations. This is the evolution of that species.
25. Explain the difference between a homologous and an analogous structure.
A homologous structure is an organ or bone in different organisms that is
similar and demonstrates a common ancestor (EX – arm/hand bones in
human, cat, whale, bat have similar components).
An analogous structure is a feature in 2 organisms that are similar but have
evolved separately (EX – bird wings vs insect wings).
26. What is a vestigial structure?
Vestigial structures are body parts that currently have no function, but
appear to have previously served one (EX – human appendix and wisdom
teeth in humans).
27. How can DNA or protein sequences be used to estimate how closely related
different species/organisms are?
The larger percentage of the difference in DNA fingerprint samples between
2 species, the longer amount of time those species have been separate from
one another in terms of branching away from a common ancestor.
28.How does comparative anatomy support the theory of evolution?
Comparing anatomy, such as the fossil record of the skulls of modern
humans against the ancestors of humans, allows us to view the similarities
and differences in traits and function over long periods of time.
29.How does biochemical/genetic evidence support the theory of evolution?
Genetic evidence, like DNA sequences, show that over time, changes in the
DNA sequences equate to large physical differences between species with
common ancestors.
30.Why do evolutionary scientists study embryonic stages of development?
During the embryonic stage of reproduction, embryos of many different
species can appear almost identical (EX – humans vs pigs vs fish vs cow
vs…etc), but then begin to appear different as the organism develops.
31.Explain how the ideas of Lamarck and Darwin differed. Whose are still accepted?
Lamarck was an early evolutionary theorist that slightly predated Darwin
and Wallace. Lamarck claimed that offspring could inherit acquired traits
from their parents (such as training to be stronger, than having your
offspring inherit that strength), as well as evolve traits by “need” (such as a
giraffe stretching out its neck to reach higher tree leaves).
Darwin and Wallace’s ideas are still accepted disproving Lamarck’s
hypothesis.
32.What is the approximate age of the Earth, in years, according the scientists?
About 4.5 billion years old.
33.What did Oparin’s hypothesis say?
Oparin suggested that Earth began to form “life” around 3.9-3.5 billion years
ago by molecules in the early atmosphere of Earth (carbon dioxide, methane,
ammonia, water vapor) reacting to produce biological macromolecules that
are essential to life (proteins, carbohydrates, fats, nucleic acids).
34.According to most scientists, which gases were found in Earth’s early
atmosphere?
As mentioned above, carbon dioxide, methane, ammonia, water vapor.
35.What happened in the Miller-Urey experiment?
The Miller-Urey experiment attempted to replicate the conditions needed to
simulate Oparin’s theory.
They placed the gases found on early Earth (mentioned above) into a closed
container and ran electrical current and heat into the system to simulate the
conditions on Earth at the time. They found that 10-15% of the carbon
molecules would react to form molecules similar to amino acids, which are
the molecules that make up protein chains.
36.Be able to explain why and how evolution is occurring given scenarios. A good
way to review for this is to use examples from class.