B14 Flashcards
What are 2 reasons for differences in characteristics in species
difference in gene inheritance
their environment
how is the environment a cause for plant variation
plants may be affected by lack of light, nutrients or space to grow
how is the environment a cause for human variation
too much or too little food
if the mother drinks or smokes during pregnancy
what are some examples of selective breeding
disease resistance
animals that produce more milk or meat
aesthetic plants
what are some disadvantages of selective breeding
reduces the number of alleles in the population
less variation
a change in the environment could kill a whole population
what is genetic engineering
involves changing the genetic make up of an organism
how does genetic engineering work
a gene for a desired characteristic is cut out of the chromosome of an organism using an enzyme
gene is then inserted into the chromosome of another organism
what is tissue culture
process of taking small groups of cells from part of a plant and growing them under special conditions
a callus forms and each new cell can be grown into a plant
what is a callus
a mass of identical plant cells
what is tissue culture used for
used to reproduce large numbers of a rare or top quality plant
how else can plants be cloned
by taking cuttings and growing them
how are animals cloned
an embryo with unspecialised cells is split into smaller groups of cells
each group of identical cells is transplanted into a host animal and allowed to develop into an individual
how does adult cell cloning work
the nucleus of an adult cell replaces the nucleus of an egg cell
the new cell is given an electric shock that makes it divide into an embryo
once the embryo has developed into a ball of cells it is inserted into the host
what are benefits of using genetic engineering
if a person has a genetic disorder, the correct gene can be trasferred to the person to cure it
several medical drugs are produced by genetic engineering
