bio exam 2

DNA replication

Creates 2 copies of OG DNA molecule, semi conservative

Helices enzyme

Unwinds the DNA double helix

DNA polymerase enzyme

Creates new complementary strands by adding nucleotides

DNA profiling

Allows us to identify unique characteristics in DNA

Short tandem repeats

A good type of DNA segment to use for DNA profiling

1st step of DNA profiling

Collect cells and extract data

2nd step of DNA profiling

Amplify STR regions by PCR

3rd step of DNA profiling

Separate STR using gel electrophoresis

4th step of DNA profiling

Compare STR banding patterns

5th step of DNA profiling

Using multiple STR regions makes the chance of another person sharing that profile impossibly small

PCR

Polymerase chain reaction

Proteins

Folded polymers made of repeating subunits of amino acids

• sequence determines protein shape

Genes

A sequence of DNA that contains instructions to make proteins

Gene expression

Making protein from a gene

Regulatory sequence

On and off switch for the gene

Coding sequence

Controls amino acid sequence of the protein

Transcription

Transforms DNA to RNA

Translation

• mRNA associates with a ribosome

• Ribosome reads mRNA in codons

• Completed amino acid folds

Universal genetic code

Set of rules relating particular mRNA codons to particular amino acids

Genetic engineering

Manipulating the genome of a living organism

GMOs

Organisms that have received recombinant genes

Create a recombinant gene

• Create a recombinant gene

• Insert recombinant gene into living cells

• Produce protein product

Mutations

Changes in DNA sequence

Point mutations

Substituting one nucleotide for another

Frameshift mutations

Change in the reading frame of a gene

Rearranged DNA mutations

Sections of DNA move

Mutagens

Chemical/physical agent that can damage DNA by changing the nucleotide sequence

Gene therapy

Replacing defective human genes with healthy ones

Viral vector approach

Modify stem cells

Gene switch approach

Changing gene expression

Precise gene editing

Making changes to existing genes (CRISPR)

Greenhouse gasses

• Energy from the sun reaches earth primarily as light

• Light interacts with earth and radiates back to space as infrared radiation

• These gasses intercept and reflect energy back to earth, heating it

Keeling curve

• Trend 1: annual cycle driven by photosynthesis and aerobic radiation

• Trend 2: annual increase in CO2 from combustion of fossil fuels

CO2

Most abundant greenhouse gas and responsible for earth warming

Fossil fuels

• 100s of millions of years old

• Do not contain specific carbon 14 isotope

• Dilutes amount of other carbon isotopes when burned

Methane

Many times more powerful as a GHG

Individual level ecology

A single organism of a particular species

Populations

A group of individuals of the same species living and interacting in the same region

Community

Interacting populations of different species

Ecosystem

Species interacting with other biotic species and abiotic environment

Growth rate

Birth rate minus death rate

Exponential growth

Rapid unchecked increase in population

Logistic growth

Pattern of growth observed when populations are limited by environmental factors

Carrying capacity

Maximum number of individuals that can be supported in an environment based on space and resources

Abiotic factors

Density independent

Biotic factors

Density dependent

Community ecology

Study of how interacting populations of different species living in the same area at the same time

Niche

Combination of physical space, environmental conditions, and resources that species require

Competitive exclusion

One species outcompetes another

Resource partitioning

Resources are divided/partitioned to reduce competition

Bison

• Once 30-50 million

• By late 1800s, hunted down to 500

• Now at 500,000

Keystone species

Not the most abundant species but if lost, there is a huge impact on the ecosystem

Nutrient cycle

Nutrients can be recycled/reused

Carbon, nitrogen, phosphorus, other nutrients

Required by living creatures

Nitrogen cycle

Nitrogen atoms cycle between different chemical compounds as they move from organisms to the soil, water, and air, then back to organisms

Dinitrogen

Abundant but biologically unavailable

Phosphorus cycle

Added to an ecosystem by the weathering of rocks or through human activities

Phosphorus

• Key component of ATP

• Chemical backbone of nucleic acids and phospholipids

• In animals, critical for bones and teeth

Energy

• Flows through an ecosystem

• Not recycled through nutrients

• Dictated by thermodynamics

• One way flow from the sun through food webs

Grasslands

One of the most imperiled ecosystems in the world

American prairie reserve

Rewilding effort to restore 3.2 million acres of land