ANT100Y1 Lecture Notes - Lecture 2: Torus Mandibularis, Messenger Rna, Somatic Cell
anthro lec 2 – principles of evolution 10/2/2015 12:10:00 AM
Modern synthesis of evolution
• focuses on how evolution works at level of phenotypes, genes, and
populations
• microevolution
• macroevolution
DNA → RNA → PROTEIN
Genetics
• Somatic cells: most cells in body (except sex cells)
• Gametes: sex cells (sperm and ovum [egg])
• Cytoplasm: complex mix of membranes, molecules, and tiny structures
called organelles
• Nucleus: contains hereditary material, known as chromosomes
Chromosomes
• Paired rod-shaped structures in cell nucleus containing genes that
transmit traits from generation to generation
DNA
• Deoxyribonucleic acid: nucleic acid used to store genetic information that
codes for the synthesis of proteins
• Four bases: Adenine (A), Guanine (G), Cytosine (C), & Thymine (T)
RNA (ribonucleic acid) molecules:
1. Dictate synthesis of proteins that perform a wide variety of functions in
body
2. regulate expression of other genes
3. work with structures in cell (ribosomes) that are critical for
manufacture of proteins
4. Transport amino acids to ribosomes for the creation of proteins
Proteins
• Linear sequences of amino acids; building blocks of cells
• each protein has specific function determined by “blueprint” stored in
DNA
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• e.g. catalysis of all biochemical reactions is done by enzymes, which
contain protein (digestion); and many more
Transcription
• synthesis of single strand of ribonucleic acid (mRNA: messenger
RNA) at unwound section of DNA with one of DNA strands serving as
template
• Result: genetic information encoded in DNA is transferred to RNA
• mRNA carries information into cytoplasm, then protein synthesis occurs
via translation
• allows information to move from one cell to the other
Codons
• Genetic information encoded in sequence of three nucleotides termed
codons
• a sequence of 3 bases – that sequence to a specific kind of amino acid
• Four nucleotides of RNA are: adenine (A), guanine (G), cytosine (C), and
uracil (U), which replaces thymine (T) in DNA template
Translation
• tRNA (transfer RNA) is information adapter molecule
• direct interface between amino acid sequence of protein & information in
mRNA
• therefore, it decodes information in mRNA
• acceptor stem is site where specific amino acid is attached
• anticodon reads information in a mRNA sequence by base pairing
Genetics & Heredity
• Gene: chemical unit of heredity
• Phenotype: observable physical appearance of organism; may or may not
reflect genotype or total genetic constitution
• Genotype: the total complement of inherited traits or genes of an
organism
• Alleles: one member of a pair of genes
• Homozygous: possessing two identical genes or alleles in corresponding
locations on a pair of chromosomes
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• ex. YY or yy
• Heterozygous: possessing differing genes or alleles in corresponding
locations on a pair of chromosomes
• ex. Yy
• Dominant alleles: allele of gene pair that is always phenotypically
expressed in heterozygous form
• ex. Y always expressed phenotypically when paired with y (Yy)
• Recessive alleles: allele phenotypically suppressed in heterozygous form
& expressed only in homozygous form
• ex. y only expressed phenotypically when paired with y (yy)
o e.g. mandibular tori
Mutation
• error or change in a nucleotide sequence
• randomly occurring process
• somatic cell mutations in terms of relevance to evolutionary anthropology
• can be neutral, harmful, or (very, very rarely) beneficial for organism
• ex. ccr5-delta32 mutation confers HIV-1 resistance in homozygous
condition
• result of four things:
• copying errors in cell division
• exposure to radiation
• exposure to mutagens
• exposure to viruses
• ultimate source of new genetic materials in populations
Population Genetics: Genetic Drift
• Random changes in gene pool over time
• Three important outcomes:
• reduces within-population genetic variation
• more likely to effect small populations
• increases between population genetic variation
Population Genetics: Gene Flow
• Movement of genes between populations
• two important outcomes:
find more resources at oneclass.com
find more resources at oneclass.com
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Document Summary
Modern synthesis of evolution focuses on how evolution works at level of phenotypes, genes, and populations: microevolution, macroevolution. Genetics: somatic cells: most cells in body (except sex cells, gametes: sex cells (sperm and ovum [egg], cytoplasm: complex mix of membranes, molecules, and tiny structures called organelles, nucleus: contains hereditary material, known as chromosomes. Chromosomes: paired rod-shaped structures in cell nucleus containing genes that transmit traits from generation to generation. Dna: deoxyribonucleic acid: nucleic acid used to store genetic information that codes for the synthesis of proteins, four bases: adenine (a), guanine (g), cytosine (c), & thymine (t) Proteins: linear sequences of amino acids; building blocks of cells, each protein has specific function determined by blueprint stored in. Dna: e. g. catalysis of all biochemical reactions is done by enzymes, which contain protein (digestion); and many more. Transcription: synthesis of single strand of ribonucleic acid (mrna: messenger.
