Genetic Variation and its Control - B1

Genetic Variation and its Control - B1

1. There are differences of course between different species of plants and animals, there are also differences between individuals of the same species.

   • the differences are due partly to the info in cells that they've inherited from their parents.
     • also, partly from the different environments in which the individuals live and grow

2. GENETIC CONTROL

   • Asexual reproduction can be used to produce individuals that are genetically identical to their parent.
   • Scientists can now add, remove or change genes to produce the plants and animals they want.

3. Why organisms are different

   • similar characteristics = found in genes
     • genes are passed on in the sex cells(gametes) from which offspring develop
   • the nucleus of the cell contains the CHROMOSOMES
     • CHROMOSOMES carry the genes
       • different genes control the development
         • of different characteristics of an organism
   • variation can be caused by the conditions in which the organism has developed
     • (ENVIRONMENTAL FACTORS)

4. REPRODUCTION

   • SEXUAL REPRODUCTION
     • is the joining (fusing) of male and female gametes
       • the mixing of the the genetic info of the two parents leads to genetic variation in the offspring
   • ASEXUAL REPRODUCTION
     • involves only one parent and the offspring are genetically identical (clones)
       • CLONING TECHNIQUES
         • plants can be grown from cuttings of a parent plant
         • TISSUE CULTURE
           • - using small groups of cells from the parent plant to produce large numbers of plant
         • EMBRYO TRANSPLANTS
           • - splitting apart cells in an embryo and implanting them into host mothers
         • ADULT CLONING
           • - removing a nucleus from an egg cell and inserting one from a body cell: after treatment, the embryo is implanted into a womb
           • Adult animals that have outstanding features can be cloned for meat or milk production.
             • 1. The nucleus is removed from an unfertilised egg cell
               • 2. a nucleus from a body cell is inserted into the egg cell
                 • 3. the cell is triggered to divide via electric shocks
                   • 4. this embryo has identical genetic info to the body cell
                     • 5. this embryo is inserted into the host womb
                       • its development continues to produce a clone of the parent

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