Scientific Method and Life Characteristics

Scientific Method

• Inductive reasoning moves from specific data to a generalization
• Deductive reasoning moves from a general principle to specific observations
• The independent variable is controlled by the scientist and affects the dependent variable; it's plotted on the x-axis
• The dependent variable is measured at the end of an experiment and plotted on the y-axis
• Controlled experiments test one variable at a time
• A control group lacks the tested variable
• Variables not being tested should be controlled
• The independent variable is changed, and the dependent variable depends on the changed independent variable

Characteristics of Life

• Living things are complex and organized
• Living things can sense and respond
• Living things can regulate their own body
• Living things have the potential to reproduce
• Living things grow and develop
  • Growth corresponds to mass and sized
  • Development refers to form, structure, and cell specialization
• Living things use energy
• Living things evolve
• Living things have complexity
• Living things have the ability to reproduce
• Living things use a form of energy production
• Living things maintain body regulation
• Living things are able to respond and react to their environment

Biological Levels of Organization

• Cells are the basic building blocks of life
  • Include cell membrane, also know as plasma membrane which separates exterior from interior of cell
  • Include watery cytosol, the internal environment of the cell
  • They may or may not have DNA in the nucleus
  • Organelles are tiny organs with specific functions
• Tissue is a group of cells with similar functions
• An organ structure has two or more tissues
• Organ systems are composed of multiple organs
• Organisms are individual living entities
• A population consists of a species in a specific area
• A community consists of different species in a specific area
• An ecosystem includes the community and non-living factors
• A biome is all the same ecosystems
• The biosphere includes all ecosystems on the planet

Prokaryotic vs. Eukaryotic Cells

• Prokaryotic cells do not have a nucleus
• The DNA floats freely
• They lack membrane-bound organelles
• Eukaryotic cells have DNA in a nucleus
• Eukaryotic cells have membrane bound organelles

Emergent Properties

• As complexity increases, new properties arise in something complex

Basic Genetics

• DNA carries information for making proteins
• Genes are portions of DNA that code for a protein
• Genes determine traits through gene expression
• Alleles are different versions of the same gene
• Alleles present affect different hairlines (W) or (w), and are passed down from each parent
• Genotype is the genetic makeup of an organism
• Phenotype is observable traits
• WW or Ww result in a widows peak, while ww will result in a straight hairline

Inductive vs. Deductive Reasoning

• Inductive reasoning goes from a specific example to a general point
• Deductive reasoning goes from a general point to a specific example

Deductive vs. Inductive Examples

• Qualitative observations use inductive reasoning by observing a specific thing and using that to make a generalization
• Qualitative observations use deductive reasoning by using observations, that generally happen in nature, to make more specific points

Independent, Dependent, and Controlled Variables

• The independent variable is controlled by the user
• The dependent variable changes depending on changes of the independent variable
• Controlled variables remain the same throughout all tests

Controlled Experiments

• Controlled experiments test one specific thing while something about it is changed
• A control group is left unaffected
• Variables not being tested are kept constant and controlled

Purpose of Controlled Experiments

• The purpose of a controlled experiment is to test one specific variable

Define Cells

• A cell is the smallest unit of life
• A cell includes the cell membrane, watery cytosol, nucleus, membrane bound organelles, and DNA (in nucleus for eukaryotes)

Define Gene, Allele, Genotype, Phenotype

• A gene is a portion of DNA from parents that determines traits
• An allele is the expression of a gene
• A genotype is the genetic expression of genes, genetic makeup, to give a character
• A phenotype is the visual expression of the phenotype

Alleles

• Each person has two alleles, and one is passed down during reproduction

Evolution

• Evolution is change over time
• Decent in modification is evolution
• A change in allele frequency over time is evolution

Decent with Modification

• Modification implies descendents and means change
• Evolution requires change in population over generations
• Evolution must be an inherited trait, genetic

Change in Allele Frequency over time

• Alleles are different versions of the same gene

Number of Alleles

• All alleles in a population is the gene pool
• The gene pool can be calculated using the formula: Gene pool = population size * 2

Allele Frequency

• Allele Frequency = (total number of specific Allele) / gene pool
• Will always be a decimal
• Should include 3 significant figures
• If the allele frequency doesnt change, there is no evolution for that gene

Mutations

• Mutation leads to variation, which is required for evolution
• Mutation is an error or change in DNA
• Mutations can occur during errors in DNA replication
• Only mutations in egg/sperm affect evolution

Evidence of Evolution

• Direct observations
  • Resistance bacteria survives antibiotics, and can reproduce to continue to survive
• Fossil Records
  • Shows changes over time
• Homology
  • Similarity due to common ancestor
  • Same bones and pattern, however they have different sizes and functions
• Vestigial Structures
  • A structure in an ancestor that is reduced and is not used in descendants
• Biogeography
  • Places where living things live
  • Where related species live close together because they had a common ancestor in that area

History of Evolutionary Thought

• Ancient Greece
  • Aristotle opposed evolution and viewed species as fixed
  • He proposed a "Ladder of Life" going from plant to human
• Carolus Linnaeus
  • Created Linnaean classification and group organisms with similar traits
  • Believed God made organisms specific
• Georges Cuvier
  • Proposed catastrophism
  • Noticed changes in fossil records
  • Proposed extinction
• Catastrophism
  • A theory that extinctions occurred due to catastrophes which changed the world
  • Each strata or layer was a catastrophe
• Charles Lyell
  • Scottish geologist
  • Proposed uniformitarianism
  • Believed Earth's landscape was shaped by slow changes and the Earth was very old
• Jean-Baptiste de Lamarck
  • Believed organisms changed in a lifespan by need of change, then passed down the trait; this is called inheritance of acquired trait
• Charles Darwin
  • Studied natural selection
• Alfred Russel Wallace
  • Developed a natural selection idea nearly identical to Darwins
  • Asked Darwin to check his work
  • Darwin and Wallace published the idea together

Define Evolution

• Evolution is the process of genetic variation over time
• Evolution includes a change in allele frequency over time

Allele frequency and genotype frequency

• Allele frequency is the number of the allele divided by the total number alleles, which is population number multiplied by two
• Genotypic frequency is the number of the specific genotype divided by the population number

Conditions for Evolution

• A scarcity of resources (food/water)
• Mutations in genes
• Changes in allele frequency
• Natural selection

Mutation

• Mutation is a change in DNA
• Mutations can occur during DNA replication
• Mutations must be in sperm or egg
• Mutation is a random occurrence

Why isnt all change over time evolution?

• Change over time can be in a lifetime; evolution needs to be an inheritable trait
• Evolution requires genetic mutations that are passed on

Evidence of evolution of nature

• The fossil records change over time
• Homology: similar bone structure shared with others
• Vestigial structures: structures no longer used but present, and used by an ancestor
• Biogeography: similar traits for species in similar locations

Homologies vs. Analogies

• Homologies are similarities of different organism due to common ancestor
• Analogies are similarities between organisms due to environment around them
• Analogies dont connect with common ancestor

Convergent Evolution

• Independent organisms evolve similarly, this can be known as analogies

Define the primary mechanisms of evolution

• Natural selection is the effect where nature selects the best gene suited for survival and reproduction
• Sexual selection happens when the mate chooses favorable traits which result in losing aspects of survival
• Genetic drift is a type of random change in allele frequency with the respect gene
• Gene flow is a movement of a gene into or out of a existing population
• Mutations introduce new alleles

Artificial Selection vs. Natural Selection

• Both can be mechanisms of evolution
• Both cause changes in a population
• In natural selection, nature chooses genes best fit for survival and mating and in artificial selection humans select desireable traits

Conditions for natural selection

• Resource scarcity, like food or water within a population
• A change in genes can be passed on

Change of allele frequency in pop. undergoing natural selection

• Green and brown beetles live on a brown tree, and their predator naturally will see the green beetles before the brown ones. This will lead to an increase of allele frequency in the brown beetles, which is better for survival.

Intersexual vs. intrasexual selection

• Intersexual selection is when the female selects a more desirable male. This usually increases chances of reproduction, but decreases survival chances
• Intrasexual selection occurs when animals fight for reproduction, which usually means the males of this species will be stronger/larger.

Define Gene flow

• Gene flow can occur if a group of brown beetles and green beetles live in two seperate populations and one day a green beetle decides to go join the beetle population, this migration results in gene flow.
• Gene flow is typically random
• Gene flow can happen based on reason, and will not happen randomly for a population to migrate

Genetic drift

• Genetic drift can happens peacefully with a group of brown and green beetles, then a man comes and accidentally stomps on the green beetles. There will be only brown alleles which is gene flow.

Special cases of genetic drift

• Bottleneck effect can occur when a large population experiences a catastrophe and is now small (less diverse population).

-Founder effect

• The founder effect happens when a population becomes isolated, which reduces diversity in both new populations

-Founder effect vs. Gene flow

• Founders effect happens when isolated population forms new population
• Gene flow happens when part of a population moves into another existing population

Allele frequency and Genotype

• Allele frequency is used to the allele divided by the total number of alleles and multiply by two
• Genotypic frequency is the number of a specific genotypen divided by population number

Hardy - Weinberg Equilibrium

• A population will be at equilibrium when -There is no evolution occouring -There is no selection
  • There are no mutatuions
  • There is mating occouring
  • It has be random HWE is tested here using these equations -Frea(A) = P Freea(A') = q -Free (AA) = Q*a2 Freq(AA) = 2pq P?+2pq+q2=1 -If an actual genetype is created, the population with then be in HWE and not evolving
• If the reverse can tested when genetype will not exist
• If genetic drift is always occurring or unless the population is infinitely large
• If a huge propulation the genetic drift barely will affect A'2 Freq(A) *

Mutations

• New Alleles can create
• Evolutionary can exists when it has created Mechanism either decreasing and occurring

1.Define the primary mechanisms of evo

• Natural selection - Nature selects best gene suited fore survival preproduction

• • Sexual selection is is when the male chooes favorable traits or survival

• -The gentics drifts randomness to genetic chagnes

• Genas is an existing moving pop

• -Mutations introduce new alleles as always

2. Artificial Selection vs Natural Selection

• both can be be mechanisms of evolution or evolution
• The creation which comes in because natural selections best suited the traits where humas chose traits

3. Conditions For Natural Selection

• Scarcity of resources food and water Genes mutatuions or the changed can be created to be passed on

The Allelie Frequency can be affected of Change

-The tree bark colors can help if green and brown become predartory on trees

• The allieus will be created to form which helps them to evolve through survival

The Intersexual vs Intrs exaul can be affected

-Which will choose desirable one for mating (females) and -Which are more produced and which will be a lower chance survive -The Reproduction is all for Reproduction

- Gene Flow

-If the beetle helps them to move 9 the flow can help them migrate from one form -Gene Flow helps them all to understand the reproduction, and will help them random -Both Based and to see if any are on an island or not

7. Genetic Drift

• If there is life where it exists with where one living one dies and it all starts with of small

Bottleneck Effect that Can affect genetics and to be created

With one to make them have survival with is more small and diverse

9. Founders Effect is always more affected

Which needs a part of them with some types can have some small genetics,

* Founder's Effer vs. Gene Flow

• Founders effect - Population created with new pop small from outside
• Gene will move the type for which all will form

-Hardy winebug affect

• A population os at HE when no evolution occurs or is needed
• No mechensism to have the evolutiom to occur

Speciees

• Species a universal defenition when all will be competing with a certain level

• Morpholical has organism that when it differs the shape it will be different

• The Benfiits for it all will be easier to test

• The limitation is it come be be that can can come from outisde

• With the look

• Genetic can not be to certain it might but certain for them but is to be same

The benefitts that have all of microorganisms

• which has the type of what ever needs to be needed

Limitates all for use expensive and extinct ones and it help some be have more expereince to see all will be needed the same

3. BIological Species concept * Emst Mayr definded species as: "a

Group of interbreedung population that are reproduction

• Species are organism that are reproduce If organism has certain one there all will be reproduce

limitations: for reproduction and how

Hard to test

• Can not use in extunice types If they can reporduc e a viable one for off spring the one that has to be needed

Reproduction

• Barrier
• Pregzyotic has a certain one For befofe Futterlizatuon CAN BYE DUE WHEN THERE NOT mating or for reproduction

types for pre ziotic Behavior is not correct There Mechanical to have reproduction Organs don't work eachother

2. GAMETIK ICOLATIONS IS WHEN THERE NOT WORKING

Ex has sea animals to release them

• There is is pos ziotic barrier with is after filterlizatuon has been created

• reduced fertility and the has to be

• reduce to have survival Hybrids don't survive reproduction ones

• Reduce for fertility, if they are inferitle

Speciation is when the pro csess of crating