Bio 1113 Exam 1

Define biology

study of living organisms and how they’ve evolved

What are the characteristics of all living organisms?

Cells and organization, chemical uniqueness, hierarchy of organization

Define metabolism

all the chemical processes in a cell

What is energy used to react to?

stimuli in and outside the cell, respond to environmental change, create adaptations and behavior that support survival

When did life begin on earth?

3\.5-4 bya

What were the first organisms?

Prokaryotes

What are the 4 overlapping Stages of the Creation of Life?

1. Amino acid and nuceleotides produce before existence of cells
2. nucelotides polymerize to become nucleic acids
3. Polymers become membrane bound
4. Membrane bound polymers evolve cell properties

What was primitive earth’s atmosphere like?

Atmosphere contained: N2 and CO2. There was little O2. Ozone layer nonexistent

Describe the primordial soup

mineral rich liquid water whete the first biomolecules and organisms arose

Explain the Extraterrestrial Theory

organic matter came from asteroids and comets that stocked the primordial soup with organic carbon, amino acids, and nucleic acid bases

Explain the Deep Sea Vent Theory

Key organics arose from deep sea vents. Water rich with H2S, metal ions, and ammonia. Ammonia is important because it forms the base of nucleic and amino acids

What does the Clay Hypothesis attempt to explain?

How primitive/early cells came to be

Explain the Clay Hypothesis

simple organics began to polymerize on solid surfaces (clay, mud, inorganic crystals) and small monomers linked together to become complex polymers

What is a probiont?

Early cell-like structures

What are some of the properties of RNA that made it useful for primitive organisms?

Capacity to store info, enzymatic activities (ribozymes), capactiy for replication

Why was RNA replaced by DNA for information storage?

DNA is a more stable molecule that’s less prone to mutation

Why was RNA replaced by proteins for enzymatic responsibilities?

Proteins are more efficient than ribozymes and have greater enzymatic potential. Proteins also have more uses like cytoskeleton structuring and transportation capabilities

Define fossil

remains and traces of past lifew; traces of organisms in sediment

Define strata

layers of rock

Where are the older strata? Where are the younger strata?

Older = towards bottom Younger = towards top

What are index fossils?

Easily recognizable fossils w/ lots of specimen (high number of them)

Why are index fossils useful?

They can tell us about surrounding specimen and help determine relative dates of embedded fossils

What is paleontology?

Study of the fossil record

What is the fossil record?

history of life and evolution preserved in sedimentary rock

Is the fossil record complete?

Absolutely not; there are plenty more fossils to find

What are some problems with the fossil record?

* not all animals fossilize equally
* organisms w/ hard body parts tend to fossilize better
* organisms w/ large populations have a better chance of being found
* larger organisms more likely to be found
* bias of paleontologists
* marine animals more likely to be fossilized than terrestrial
* organisms that lived longer more likely to become fossilized

What is relative dating?

approximate era of when an extinct organism lived

What do we use for relative dating?

index fossils

What is absolute dating?

System of dating using radioisotopes

Define radioisotopes

length required for half the atoms to change into something else (half-life)

Why is carbon-14 particularly useful?

Carbon begins to decay into nitrogen 14 as soon as the organism dies. Gives most accurate age of fossil.

How is the Geologic Time Scale broken down? (biggest time periods to smallest)

Eons, eras, periods, epics

Name the three Eons

Archean, Proterozoic, and Cenozoic

Of the 3 eons, which 2 are part of Precambrian Time?

Archean and Proterozoic Eons

What does the suffix -zoic mean?

animal

What is the mnemonic device for the 5 mass extinctions?

Our Dog Pat Takes Cats

Name the 5 Mass Extinctions (In order)

Ordovician, Devonian, Permian, Triassic, Cretaceous

What was the biggest mass extinction in history?

Permian extinction: 95% of marine life killed.

What period is the Permian extinction between

Permian —> Triassic

What era is the Permian extinction between?

Paleozoic —> Mesozoic

Define Evolution

heritable change in one or more characteristics of a population or species from one generation to the next

Do individuals or species experience evolution?

Species

Do individuals or species experience natural selection?

Individuals

Define population

members of the same species that are likely to encounter each other and have the opportunity to breed

What are the two types of evolution?

Microevolution and macroevolution

Define microevolution

changes in a single gene in a population over time (small gradual changes)

Define macroevolution

formation of a new species over time; quicker more dramatic change, then little to no change

What is Aristotle’s contribution to evolutionary thought?

*Scala Nature* classification system

What did Erasmus Darwin contribute to evolutionary thought

Idea of common descent, developmental patterns, artificial selection, vestigial organs

Who is the founder of paleontology and catastrophism?

Jean Cuvier

What did Lamarck say about how complex organism arise?

complex organisms come from less complex organisms

What is Lamarckism?

idea that acquired traits (becoming strong from working out) can be passed from parent to child

What is uniformitarianism?

rates and processes of change are constant

What did Darwin use to support his ideas?

morphology, biogeography, paleontology, and embryology

What are homologous structures?

anatomical similarities due to sharing a common ancestor

What are analogous structures?

parts that serve the same function but have different structure (are not similar bc of common ancestor)

What is the cause of analogous structures?

convergent evolution

Define convergent evolution

similar environmental pressures causing otherwise unrelated species to evolve similar traits

What are vestigial structures?

structures that are fully developed but reduced in function or obsolete (appendix)

Who is Alfred Russell Wallace?

competitor to Darwin for ideas of evolution, father of biogeography. theorized that continental drift and plate tectonics affect how species evolved

List the steps 4 in the process for genetic variation

1. Variations come from sexual reproduction and chance mutation
2. Natural selection selects fittest orgnism
3. Natural selection leads to adaptation to a particular diagram
4. Process occurs in ALL species

What causes microevolution?

Genetic mutation, gene flow/migration, nonrandom mating

What are the 2 types of nonrandom mating?

Assortative and Disassortative mating

Define Assortative mating

individuals select mates w/ similar phenotypes, increase number of homozygotes

Define Diassortative mating

non similar phenotype mate preferentially, increases number of heterozygotes

Define genetic drift

changes in allele frequency due to random chance

Bottleneck effect

population is severely reduced along with its genetic diveristy

Founder effect

new population is started and recessive and rate alleles expressed more frequently due to a lack of genetic diversity

What are the 3 types of natural selection

Directional, stabilizing, and disruptive selection

Directional Selection

individuals at one extreme have greater reproductive success

Stabilizing Selection

intermediate or middle is the dominant and fittest of the population

Disruptive Selection

two or more extreem phenotypes are favored over intermediates bimodal distribution

Define the Hardy-Weinberg Principle of Equilibrium

a population’s allele and genotype frequency are stable UNLESS some evolutionary force is acting on them, neither the allele or genotypic frequency would change

What’s the problem w/ the Hardy-Weinberg Principle of Equilibrium?

* assumes infinitely large population
* in a condition w/ no migration, emigration, mutations, or selection pressure

Why is the HW principle useful?

offers a useful model against which to compare real population changes

Anagenesis

transformation of one species into a new species over time

cladogenesis

splitting of one species into two

Define species (two definitions)

* group of related organisms that share a distinctive form and can interbreed to produce viable offspring
* irreducible group of organisms diagnosably distinct from other such groupings within there is a parental pattern of ancestry and descent

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What are the two Reproductive Isolation Mechanisms

prezygotic and postzygotic mechanism

Prezygotic mechanisms

mechanisms in place that discourage attempts to mate between specifgic organisms

Postzygotic mechanisms

mechanisms that prevent hybrid offspring from developing or breeding

Allopatric speciation

geographic isolation of one or more groups of the same species causing them to become different species

Sympatric speciation

occurring within a parent species’ remaining in one location

adaptive radiation

varied demands of species’ new lifestyle leading to MULTIPLE speciation events from a SINGLE species

Taxonomy

branch of biology concerned w/ identifying, naming, and classifying organisms

systematics

study of biological diversity and evolutionary history of life on earth

Binomial Nomenclature

*Genus specific epithet*

Classification system

* Domain
* Supergroup
* Kingdom
* Phylum
* Class
* Order
* Family
* Genus
* Soup

Phylogenetic Trees

diagram indicating lines of descent

Primitive characters

present in ALL members of a group AND in the COMMON ANCESTOR

Derived characters

present in SOME members of a group BUT absent in the common ancestor

Parallel Evolution

independent evolution of similar traits starting from a similar ancestral condition; species responding to similar challenges in a similar way

Ontogeny

development of an organism/study of the development of an organism

Phylogeny

an organisms’s evolutionary descent or diverisification from a common ancestor

What do traditional systematics emphasize/stress

phenotype

Monophyly

most recent common ancestor and ALL DESCENDANTS

Paraphyly

includes common ancestor but NOT ALL DESCENDANTS

Polyphyly

members are traced to different ancestors

How does the Cladistic Classification system classify organisms>

synapomorphies

What are synapomorphies?

shared derived traits; homologous features