STS101 Finals

• Gene theory is a fundamental

  concept in biology that

  explains how traits are passed

  from parents to offspring.

  It provides a framework for

  understanding genetics,

  heredity, and evolution.
• Genes are segments of DNA

  that contain the instructions

  for making proteins.

  Proteins are the building

  blocks of life and carry out

  many functions in cells and

  organisms.
• How do genes work?

  Genetic information flows from DNA to RNA to proteins.
• What is DNA?

  DNA (deoxyribonucleic acid)

  is a double-stranded molecule

  that contains the genetic

  information of an organism.

  It is made up of four

  nucleotides: adenine,

  guanine, cytosine, and

  thymine.
• What is RNA?

  RNA (ribonucleic acid) is a

  single-stranded molecule that

  carries genetic information

  from DNA to proteins.

  There are three types of RNA:

  messenger RNA (mRNA),

  transfer RNA (tRNA), and

  ribosomal RNA (rRNA).
• What is Protein?

  Proteins are the building

  blocks of life and carry out

  many functions in cells and

  organisms.

  They are made up of chains

  of amino acids that are

  folded into specific shapes to

  carry out their functions.
• Transcription is the process by which DNA is copied into RNA.

  It occurs in the nucleus of a cell and involves the use of an enzyme

  called RNA polymerase.
• Translation is the process by which RNA is used to make proteins.

  It occurs in the cytoplasm of a cell and involves the use of

  ribosomes, which read the mRNA sequence and assemble the

  corresponding amino acids into a protein.
• Biodiversity (biological diversity)

  the total variety of life on Earth

  measure of variation at the genetic

  (genetic variability), species (species

  diversity), and ecosystem

  (ecosystem diversity)
• Taxonomy is the scientific study of naming, defining

  and classifying groups of biological organisms

  based on shared characteristics.
• Carolus Linnaeus (1707- 1778)

  Swedish botanist

  Systema Naturae: a classification scheme that

  used morphology to group organisms into

  hierarchical categories
• Taxonomy: the classifying of organisms based on

  morphology and genetics.
• The broadest, most inclusive, taxonomic category is the

  Domain.

  All living things can be categorized into one of three Domains:

  Bacteria

  Archaea

  Eukarya
• Domain Bacteria

  Microscopic, unicellular

  prokaryotes

  Some species are autotrophs,

  while others are heterotrophs
• Domain Archaea

  Microscopic, unicellular prokaryotes

  Superficially similar to bacteria, but

  significant genetic differences exist

  Many archaea are extremophiles
• Domain Eukarya

  Includes unicellular and multicellular

  organisms that all have eukaryotic cells

  Includes the plant, animal, fungus

  kingdoms

  Also includes the protists, a highly diverse

  group of organisms that includes algae,

  slime molds, and much more
• Why does so much

  biodiversity exist of

  Earth?

  Evolution, by the mechanism of natural

  selection, provides a logical explanation

  for how populations change over time.

  ultimately, this change can lead to the

  creation of new species

  life has been evolving for billions of

  years on Earth
• Evolutionary theory was

  co-discovered by Charles Darwin

  and Alfred Wallace, working

  separately.

  Both traveled the world extensively,

  making observations and collecting

  specimens that helped them

  formulate their theories
• Both Darwin and Wallace recognized natural selection as a

  mechanism by which populations can evolve over time.

  Natural selection relies on variation of traits in a population

  With this variation, individuals with traits better suited to

  their environment are more likely to survive, reproduce,

  and pass on those traits to future generations.

  Over time, beneficial traits become more common,

  maladaptive traits become less common.
• Background extinction rate

  Based on the fossil record

  Estimated to be about 1 per million species years

  The problem: current extinction rates are several times

  higher than the background rate
• Extinction rates are currently so

  high that biologist argue that we’re

  currently experiencing the 6th Mass

  Extinction

  Most extinctions are due to

  anthropogenic causes

  That’s pretty messed up.
• Cartagena Protocol on Biosafety to the

  Convention on Biological Diversity

  January 29, 2000 Conference. Entered September 11, 2003 (90 days)

  163 parties to protocol
• Scope of Cartagena Protocol:

  • To protect biological diversity from the risks of Living Modified Organisms (LMO's) or Genetically Modified Organisms (GMO's) a product of modern biotechnology.
• Biotechnology is a broad area of

  biology, involving the use of

  living systems and organisms to

  develop or make products.

  Genetic engineering (also

  called genetic modification), is

  the direct manipulation of an

  organism’s genome to alter the

  genetic makeup of an organism.
• GMO

  genetically modified organism: organisms

  whose genetic characteristics have been

  altered in a way that does not occur naturally

  by mating and/or natural recombination.

  Transgene is a gene that has been transferred

  naturally, or by any of a number of genetic

  engineering techniques, from one organism to

  another.