Overview of human genetics

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 Genetics

  branch of biology
   concerned with inherited
   traits and their variations.
    Inherited – traits you
     get from your parents
    Traits- personal
     characteristics


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 Genes

  Basic unit of heredity




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                      Genes are
                       composed of
                       DNA.
                      The complete
                       set of genetic
                       information is
                       called the
                       genome.

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   Genomics is the field of biology that studies gene
    interactions.


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   Ethical Dilemma - My friend Linda




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   DNA
   Genes Chromosomes and Genomes
   Cells Tissues and Organs
   Individual
   Family
   Population
   Evolution

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   Genes consist of sequences of
    DNA.
   DNA is made of four basic
    building blocks – adenine,
    guanine, cytosine and
    adenine.
   RNA uses information from
    selected DNA sequences to
    build proteins.
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 Genes can exist in more than one
 form, called alleles.
  Mutation causes the formation of
   alleles by changing the DNA sequence.



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                        Chromosomes
                         - made of
                         genes and
                         associated
                         proteins




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                        The human genome
                         consists of 22 pairs of
                         autosomes (non sex
                         chromsomes) and one
                         pair of sex chromosomes
                        karyotype -
                         Chromosomes organized
                         by size, band patter and
                         area of constriction.



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   Specialized cells and tissues arise by
    differentiation from the stem cells of the early
    embryo.
   Stem cells are unspecialized cells that can renew
    themselves and differentiate into different cell
    types.



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                         Cells



                        Tissues



                        Organs



                     Organ systems
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 The genotype represents the alleles
  present in an individual (the DNA),
 the phenotype is the expressed allele for
  a trait (what the individual looks like).




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 Dominant alleles have an effect when
  only one copy is present
 Recessive alleles require two copies in an
  individual to be expressed.
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   Pedigree diagrams - enable recessive and
    dominant traits to be followed through multiple
    generations of a family.

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   A gene pool is the collection of alleles in a
    population




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        Comparative genomics (gene interactions) is
         leading to a more detailed and subtle
         understanding of evolutionary relationships
         among species.




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   Mendelian traits are determined by single genes.
   Multifactorial traits are determined by multiple
    genes and environmental effects.
   Environmental factors may influence gene
    expression.




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   Modified genetic risk examines the influence of
    single genes, environment, and family
    background to develop predictions of inherited
    disease
    Genetic determinism is the point of view that the
    environment has little effect on gene expression.



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   Genetic tools are used in diverse areas such as
    forensics, establishing paternity, agriculture, and
    health care




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   Establishing identity and origins
   Health Care
   Agriculture
   Ecology
   Genetics from a global Perspective



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   DNA profiling
     exclusion from being biologically related to someone
      else or from having committed a crime.
     used to analyze family relationships
     origins of groups of people in diverse areas of the
      planet.
   DNA databases.


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    Inherited diseases differ from infectious diseases in
     three distinct ways.
1.     First, it is possible to predict the recurrence of a
       single-gene disease.
2.     Second, the risk of developing symptoms can be
       predicted.
3.     Third, genetic diseases may be more prevalent in
       one population than another (sickle cell, tay-sachs).


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    Biotechnology is the use of organisms to
    produce goods.
   Traditional agriculture involves controlled
    breeding to select new combinations of inherited
    traits.
   Genetically modified (GM) foods have genes
    introduced from the genomes of other
    organisms.
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   Metagenomics is the
    application of
    genomics to all
    members of a
    habitat to
    understand how
    organisms and
    species interact.

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    Genetics has spawned new technologies and
    possibilities, including genome-based
    individualized health care.
    Human genome information has tremendous
    potential but must be carefully managed.




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