EXAM 1 - module 1,2,3 Genomes and Evolution

Bio 242 university of San Diego

Charles Darwin

The English naturalist who developed the theory of Evolution by Natural Selection, and found species come from other species. Studied finches in Galapagos and found their beak shapes demonstrated how a single ancestor species could diverge and adapt to different local food sources.

Alfred wallace

independently co-discovered the theory of Natural Selection and is famous for identifying the Wallace Line - geographic isolation drives allopatric speciation and creates distinct evolutionary histories for different regions.

Theory of Evolution

Transitional forms, speciation events, vestigial structure, experimentation, fossil record, developmental patterns, DNA homology, anatomical homology

Natural selection

Overpopulation, competition, some traits survive better than others, traits vary, traits are heritable

Science

Organizes knowledge in the form of testable explanations

Pseudoscience

Presented knowledge but lacks actual evidence

Common garden experiment

Species grow under shared condiitons

Reciprocal Transplant experiment

Moving species to places they are NOT from to see if shaped from environment or genetic code

Dominance

One allele is expressed over other

Co dominance

Two alles are expressed equally ie. white and red polka dots

In complete dominance

Both alleles of gene are partially expressed ie. white + red = pink

Blending inheritance

parental traits would permanently mix and dilute variation over time

Particulate inheritance

phenotypic traits are passed from one generation to the next through discrete, unblending units called genes (or alleles).

Discrete traits

One gene with two options ie. attached or detached earlobes

Quantitative traits

Phylogenetic traits coded by multiple genes ie. eye color

Carbon

Basis of life because of its ability to form four stable bonds allows it to create a vast array of complex, stable, and diverse organic molecules

Electronegativity

Measure of pull that an atom exerts on shared electrons with a covalent bond

Covalent bond

Sharing of a pair of valence electrons by two atoms

Non polar bond

Sharing electrons EQUALLY

Polar bond

Sharing electrons UNEQUALLY

Hydrogen bond

Weak bond where h atom is covalently bonded to electro negative atom

Four macromolecules

Carbohydrates, lipids, proteins, nucleic acids

Enzymes

Type of protein that acts as catalyst to speed up chemical reactions

Primary structure

Sequence of amino acids

Secondary structure

Structure of coil or alpha beta pleats

Tertiary structure

Three dimensional shape determined by side chains

Quaternary structure

Multiple polypeptide chains

Central Dogma

DNA to RNA to Protein

Transcription

a gene's DNA sequence is copied into a messenger RNA (mRNA) molecule, rewriting the genetic instructions in the language of RNA.

Transcription initiation

The enzyme RNA polymerase binds to the promoter region of a gene and unwinds the DNA helix, setting the stage for RNA synthesis.

Transcription elongation

RNA polymerase moves along the DNA template strand in the 3′→5′ direction, adding complementary RNA nucleotides to synthesize the growing mRNA strand in the 5′→3′ direction.

Transcription termination

RNA polymerase reaches a terminator sequence in the DNA, which triggers the polymerase to detach from the DNA template and release the newly synthesized mRNA transcript.

Translation

The cell's ribosomes read the mRNA code and use transfer RNA (tRNA) to assemble a specific sequence of amino acids, thereby creating a functional protein.

Translation initiation

The small ribosomal subunit binds to the mRNA, followed by the first tRNA (carrying the amino acid Methionine) binding to the start codon (AUG), and then the large ribosomal subunit joins to form the active ribosome complex.

Translation elongation

The ribosome moves along the mRNA, sequentially binding new tRNAs in the A site, forming a peptide bond between the new amino acid and the growing chain in the P site, and translocating the complex one codon forward.

Translation termination

The ribosome encounters one of the three stop codons (UAA, UAG, or UGA) in the A site, which is recognized by a release factor protein, causing the completed polypeptide chain to be cleaved from the last tRNA and released.