Download Name: TOC#_____ Origins Unit Exam Study Guide Station 1

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Origins Unit Exam Study Guide
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Station 1: Origins of Universe and Earth
1. Explain the Big Bang theory and why it is important
The entire universe was created through a singularity that was very hot and very dense and it expanded
rapidly and is still expanding today. It created our entire universe.
2. According to the big bang theory the universe is constantly: _____Expanding_________
3. What were the first elements?
a. hydrogen/helium/lithium
4. How was the solar system created?
a. 5 billion years ago, a great cloud of gas and dust rotated in space
b. Most of the cloud’s material gathered in the center, causing it to shrink and rotate faster into a
disk shape
c. The compression made the interior so hot that hydrogen fusion began and the sun was born
d. Masses surrounding the sun separated into rings and collected to become planets
5. How was earth created? Include how the layers formed
a. was created when from mass surrounding the sun
b. Initially one, hot sphere, the interior grew hotter and melted to form layers of the earth and
magnetic fields were formed
6. How old is the earth?
4.6 billion years ago
7. What were the conditions on early earth like?
a. The early Earth was an uninhabitable, hot ball of molten lava with a uniform mix of minerals
and elements
b. Over time, the magma differentiated:
i. heavy elements sank toward the center (iron)
ii. lighter elements accumulated toward the top (silica)
3 distinct layers formed: hot radioactive core, molten mantle and a thin, brittle crust
8. How was water created?
a. Outgassing of water vapor from volcanoes condensed to form liquid water
b. Ice comets landed and melted to form water
9. How was the atmosphere created?
a. Contained mostly hydrogen (H), helium (He), methane (CH4) and ammonia (NH3)
b. Outgassing from volcanoes produced water vapor (H2O),
carbon dioxide (CO2), nitrogen (N) and carbon monoxide (CO)
c. Earth’s early atmosphere did NOT contain oxygen (02)!
10. What did the initial atmosphere contain?
a. Contained mostly hydrogen (H), helium (He), methane (CH4) and ammonia (NH3)
b. Outgassing from volcanoes produced water vapor (H2O),
carbon dioxide (CO2), nitrogen (N) and carbon monoxide (CO)
c. Earth’s early atmosphere did NOT contain oxygen (02)!
11. How was oxygen created?
a. Through photosynthesis, these bacteria produced enough oxygen to change the composition of
Earth’s early atmosphere
12. Oxygen is important because…
It allowed most life on earth to exist
13. When a period/era changes, it is often accompanied by…
Major biologic and geologic changes
Station 2: Origin of Life
1. Explain what it means that: Living Things Are Made Up of Cell(s) that contain DNA
a. Unicellular organisms are made of 1 cell
b. Multicellular organisms are made of more than 1 cell
c. Cells contain genetic information in the form of DNA
2. Explain what it means that: Living Things Reproduce
a. Sexual Reproduction: The mixing of genetic material from 2 members of the same species
b. Asexual Reproduction: Offspring are genetically identical to the parent. No mixing of genetic
material.
3. Explain what it means that: Living Things Grow and Develop
• New cells can be created and differentiate/specialize to perform certain functions for the
organism as time passes
• As development occurs, organisms age until inevitable death occurs
4. Explain what it means that: Living Things Obtain and Use Energy
a. Energy is obtained and used to grow, develop and reproduce
b. Metabolism: The total sum of all chemical reactions in the body
i. Anabolism: Synthesizing substances to store energy
ii. Catabolism: Breaking down substances to release energy
5. Explain what it means that: Living Things Respond to The External Environment and Maintain
their internal environment
Living things respond to stimuli to improve their chances for survival
Maintain their internal environment.
Homeostasis: the ability to maintain constant or stable conditions that are necessary for life
 Sweat to release heat
 Sensations of thirst and hunger
6. What is Spontaneous Generation? Is it true?
The hypothesis that life arises regularly from non-living things. Not True as shown by redi with his meat
and flies experiment
7. What experiment did Miller and Urey perform? What was the result?
Scientists have simulated the conditions of Earth’s early atmosphere, adding energy to simulate early
sunlight and lightening
Results:
a) In a few days, a “soup” of molecules formed, including several amino acids (the building blocks
of proteins)
b) Reactions such as these occur today near volcanic vents at the bottom of the sea!
8. What are Coacervates? Why are they important?
Complex Molecules that Collect and gather together into tiny round droplets known as
• In the laboratory, these droplets have been shown to grow and divide!
• Coacervates are not living cells, but their existence suggests ways in which the first cell
may have formed.
9. First cells had…were PROKARYOTIC
a. lacked nucleus
b. anaerobic (survived in absence of O2),
c. heterotrophs (cannot synthesize own food) that resemble types of bacteria alive today
d. Had RNA (not DNA) stored the genetic information
10. Define Prokaryotic
a. lacked nucleus
11. Define Heterotroph
a. (cannot synthesize own food)
12. Define Autotroph
(synthesize their own energy)
13. Define Photosynthesis
Organisms release oxygen as a waste product
14. Define Eukaryotic
with a true nucleus, DNA and membrane-bound organelles
Station 3: How evolution works
1. What are our two definitions of evolution
a. The process by which modern organisms have descended from ancient organisms.
b. Change over time!
2. What is the difference between a Fact vs. Theory
a. Fact: Has undergone repeated tests over a period of time.
b. Theory: an explanation of some aspect of nature that is supported by a vast body of evidence.
Not yet “proven” however, a valid collection of carefully reasoned and tested hypotheses,
supported by evidence.
3. Lamarck’s Theory has three principles. List and explain each.
-A Desire To Change - Organisms change because of an inborn urge to better themselves. (ex. Birds
really wanted to fly!
-Use and Disuse - Organisms could alter their shape by using their bodies in new ways (ex. Organs
would increase in size if they were used a lot and vice versa)
-Passing on Acquired Traits – Acquired characteristics are passed on to future generations
4. Was Lamarck’s theory correct?
no
5. Define Darwin’s Theory of Natural Selection: The process by which the organisms whose
characteristics are well-suited for their environment survive and reproduce.
6. What are the three Steps of Natural Selection? Explain each
(1) (Genetic)Variation: Gene mutations and recombinations provide the variation upon which
natural selection acts
(2) Selection:
In the struggle for existence, organisms either survive and reproduce or do not.
Far more organisms are born than ever grow to adulthood
Those organisms with adaptations well-suited for the environment are “selected” to survive
(3) Reproduction:
o Best-fit organisms have the highest probability of successfully reproducing
o Favorable characteristics (adaptations) will be passed on to the offspring
o Organisms in future generations will become better and better adapted to their environment
7. Define Evolutionary Fitness
the success an organism has in passing on its genes to the next generation.
8. Why is reproduction important to evolution?
Without reproduction favorable genes will not be passed on and new variations cannot occur
9. Define Adaptation
A trait or characteristic that helps or harms an organisms survival
10. Do organisms or species evolve?
species
11. Define Adaptive radiation
Organisms evolve into several different species due to capatilizing on an adaptation they have that suits
the environment: darwins finches
12. Be able to give examples of evolution (i.e. England’s peppered moths, darwins finches,
punchbugs)
Station 4: evidence for evolution
13. Know the five pieces of evidence for evolution and be able to explain each one:
a. Similarities in Early Development: Embryos of many different animals are similar in
appearance, especially during the early stages of development. The similarities of vertebrate
embryos show that similar genes are at work
b. Similarities in Body Structures: Homologous Structures - parts of different organisms that
developed from the same ancestral body part. Examples: The limbs of various vertebrates are
similar in structure
c. Vestigial Organs Organs that are so reduced in size or function that they are
merely traces
of similar organs in other species. Examples: tail bone and appendix in humans tiny bones on
the underside of pythons and boa constrictors
d. Similarities in Chemical Compounds: Genetic Material: All organisms, from bacteria to
humans, use DNA and /or RNA to carry information from one generation to the next. Example:
DNA of all eukaryotic organisms has the same structure and replicates in the same way
e. The Fossil Record: we can look at fossils and date when they were created.
14. Why do we study the past?
To understand where we came from. To find evidence of evolution
15. Define fossil
The evidence or remains of once-living plants or animals
16. Why fossils good piece of evidence
To provide evidence of the past existence of life forms
To provide information about past environmental conditions
To provide evidence that populations have undergone change over time due to environmental changes
(evolution)
17. Know each type of the 5 fossils and be able to explain how they are created/why they are
important
a. Original preservation: Original Preservation - plant or animal remains that have not undergone
change since death. Uncommon because frozen, extremely dry, or oxygen-free environments are
required to form these fossils. Examples:
i. Mummified humans
ii. Frozen organisms (Ice Man)
iii. Mammoths & cats in La Brea Tar Pits
iv. Fossilized insects in tree sap (amber)
b. Altered hard parts: all organic material is replaced with rock. Minerals seep in slowly and replace
the original organic tissue with silica, calcite, or pyrite, forming a rock-like fossil. The fossil has the
same shape as the original object, but is chemically more like a rock. Examples:
1. Petrified wood
2. Recrystallized shells
c. Index fossils: commonly used to correlate or date rock. Must be easily recognized, abundant,
and widely distributed geographically. Must have lived during a relatively short time period
d. Molds/casts: A mold is an impression/cavity of the shell of an organism. Cast - cavity might
later become filled with minerals or sediment. Common with shellfish
e. Trace fossils evidence of life other than the organism itself. Provide information about how an
organism lived, moved or obtained food
Station 5: dating Fossils
1. Define Relative-dating: Dating rocks and fossils by placing them in chronological order without exact
dates.
2. explain the law of superposition: in an undisturbed sequence the oldest rocks are at the bottom and each
successive layer is younger
3. explain the principle of cross cutting relationships: an intrusion (new magma) or a fault is younger than
the rock it cuts across
4. Absolute Dating: used to determine the actual age of a rock, fossil, or another object.
5. Define Radioactive Dating: Dating fossils based on the amount of radioactive material remaining in a
substance over time
6. define half-life: The length of time it takes for one-half of the original amount to decay
7. define isotope: An atom with an abnormal amount of neutrons. This makes atoms unstable and they
may break down
8. Complete the following half life problems.
a. Gold-198 has a half life of 2 days. If there is initially 100 grams of Gold-198, how much will
remain after 8 days?
6. 125 grams
b. What percent of the original substance will be left after 3 half lives
12.5%
c. If there is originally 16 grams of a substance with a half life of 20 seconds, how much will
remain after 100 seconds?
.5 grams
Station 6: Classification
1. Why do we classify organisms?
• Provides a universal language so scientists can communicate globally
• Groups organisms to show evolutionary relationships
2. How did scientists classify organisms in the past?
a. Initially, scientists looked at the structural similarities of different organisms
b. Taxonomists looked for similarities in physical features called homologous structures in order to
show relatedness
3. How do scientists classify organisms now?
• Now, taxonomists also consider evolution and genetics
• They look for similarities in biomolecules such as DNA, RNA, and amino acid sequences.
4. What are the levels of classification as described by Carl Linnaeaus
Kingdom Phylum Class Order Family Genus Species
5. Know why we no longer use the Linnaean system of Classification
because it does not take evolution into account
6. What is Binomial nomenclature, who invented this system, and why is it used?
The way we name organisms.
The rules:
• Scientific names have two parts: Genus and species
• Capitalize Genus, but not species
• Underline or put in italics
7. Define the following term in relation to classification:
a. Heterotroph: cannot create its own energy
b. Autotroph: can create its own energy
c. Prokaryote: cells do not have a nucleus nor membrane enclosed organelles
d. Eukaryote: cells with a nucleus and membrane bound organelles
8. What is Cladistics and how does it work?
A classification system that takes into evolution. Scientists group organisms based on shared
evolutionary history. Uses fossils, living specimen, and molecular sequencing of DNA
9. Define Phylogeny
Hypothesis of evolutionary relationships
10. What is a cladogram?
A family tree we use to show a phylogeny
Station 7: Human Evolution
1. What are the characteristics shared by all primates?
a. Flat faces, reduced snout
b. Eyes directed forward; binocular vision for depth perception; see in color
c. Flexible fingers for grasping
d. Full shoulder rotation
e. Nails (vs. claws)
f. Complex, large cerebrum
g. Extended maternal care for young; usually 1 offspring at a time; 2 mammary glands
h. Complex social groups and behavior
2. Describe Cro-Magnon: The first hominins truly identical to modern humans appeared in Africa,
roughly 100,000 years ago and were
3. Know the species order of evolution for modern humans: homo sapiens sapiens
4. Distinguish between hominoids, hominids, and hominins:
Hominoids includes the “great apes” Gorillas, gibbons, orangutans, chimps and humans
Hominids separated 4 and 9 million years ago and excludes gibbons and are
1. Omnivorous
2. Bipedal locomotion
3. Opposable thumb
4. Remarkable increase in brain size (cerebrum)
Hominins are only austrolopithicus and all homo species
5. What is the first species recognized as a modern human?
Hominins-specifically homo sapiens sapiens
6. When and where did modern humans first appear?
100,000 years ago