Hominid Evolution

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Hominid Evolution Powered By Docstoc
					            Selective Breeding
   This is a form of artificial selection
   Involves choosing individuals from a
    population that have a certain trait and
    breeding those individuals
   This is done across several generations
   Eventually the trait is seen in all of the
    offspring and becomes more pronounced
   Used in farming, agriculture, and race horses
    Reproductive Technology used in
   Artificial insemination (AI) – sperm from a
    selected animal is extracted and artificially
    introducing it into a female reproductive tract

   Sex selection through sperm sorting – sperm
    are collected and analysed – separated into
    two groups – X and Y carrying sperm – uses a
    fluorescent dye
    Reproductive Technology used in
   Multiple Ovulation Embryo Transfer
      stimulate a female to produce many eggs at
      use AI to fertilise them within the body

      after 6 days the uterus is flushed to extract
       the embryos
      these are then inserted into other females to
       begin gestation
   Cloning - creating genetically identical
    copies of an organism
   Two methods:
       Splitting embryos
            Creating an embryo using IVF and using a fine
             needle to extract embryo cells that can divide and
             form new identical embryos
       Somatic Cell Nuclear Transfer (SCNT)
            Inserting the nucleus of a somatic cell into an ovum
             that has had its nucleus removed
Gene Therapy
                Gene Therapy
   Still in development
   Attempts to introduce normal copies of
    genes into the cells of an individual with a
    genetic disorder
   Involves cloning the gene using a plasmid
    and then using a vector (carrier) to get it
    into the cells
   Vectors include inactivated viruses and
Gene Therapy
Gene therapy for Haemophilia
Prenatal Gene Therapy
                  Stem Cells

   When sperm fertilises an ovum it forms a
   The single cell grows and divides. Within 5
    or 6 days there are up to 120 cells.
   They form into a ball called the blastocyst.
   Each cell is pluripotent, capable of
    developing into any cell type in the human
    body such as heart, skin or hair.
Stem Cells

  Can make
every cell type
 in the body.

  They are
           Therapeutic Cloning – to produce
                      stem cells

A doctor takes a sample of skin cells from the patient and
isolates their DNA.
A donor egg cell, emptied of its own genetic contents, is injected
with the DNA from the patient. The embryo is nurtured to grow
and divide into a blastocyst.
Some blastocyst cells are harvested and coaxed with growth
factors to mature into insulin-producing cells. Millions of insulin-
producing cells are injected back into the patient. The patient's
diabetes is temporarily 'reversed', with no side effects .
             Genetic Screening
   Genetic screening can
    be performed for a
    variety of reasons:

     Test carrier status for a
      particular disorder
     Test whether there is a
      predisposition to cancer
     Pre-natal testing for
      expectant parents
        Reproductive technology
   Assist in overcoming infertility
   Variety of methods:
     In-vitro fertilisation (IVF) – sperm and ovum
      extracted and allowed to fuse outside of the body
      Embryo inserted into the uterus at the six cell
     Gamete Intra-fallopian Transfer (GIFT) – sperm
      and ovum extracted and injected into the
      fallopian tube of the female so fertilisation
      happens in the body
          Reproductive technology

       Intracytoplasmic Sperm Injection – sperm and
        ovum extracted and the sperm is injected directly
        into the ovum. Embryo inserted into the uterus at
        six cell stage.

   Preventing pregnancy (contraception) also
    falls under the category of reproductive
Intracytoplasmic Sperm Injection
          Questions to complete
   All Quickcheck

   Biochallenge Page 652

   Chapter Review: 2, 3, 4, 5, 6, 7, 9bcd, 11, 12

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