B14 Flashcards
(19 cards)
what causes differences in characteristics of individuals from the same species
differences in genes they have inherited
the environmental conditions in which they developed
what environmental factors changes a plants appearance
lack of light
lack of space to grow
what environmental factors can change the way a human or animal looks
in a human if they mother smokes during pregnancy
too much or too little food after birth
what is survival of the fittest
organisms with the characteristics most suited to their environment will survive and breed successfully
what is the theory of evolution
states that all living things have evolved from simple life forms that first developed 3 billion years ago
what can selective breeding do
select a wide range of features such as
disease resistant crops
high yielding animals
what are limitations of selective breeding
greatly reduces number of alleles in the population
less variation
an environmental change could destroy a population
how does selective breeding work
choose parents with the wanted trait and breed them together
select the best offspring with the desired traits
how does genetic engineering work
a gene for a desired characteristic is cut out of the chromosome using an enzyme
the gene is inserted into the chromosome of another organism using a carrier
what is cloning used for
used to produce new individuals that are useful in farming and agriculture
what is tissue culture
process of taking a small group of cells from part of a plant and growing them under special conditions
what is the result of tissue culture
a mass of identical plant cells forms, called a callus and each callus cell can grow into a new plant
what is tissue culture used for
to produce large number of a rare or top quality plant
what is a simpler way of cloning plants
taking cuttings and growing them
how do embryo transplants work
divide each embryo into several individual cells
each cells grows into an identical embryo in the lab
transfer embryos into their host mothers
identical clones are born
what happens in adult cell cloning
the nucleus of an adult cell replaces the nucleus of an egg cell
how does adult cell cloning work
first the nucleus is removed from the egg cell and the nucleus is taking from the adult cell and placed into the egg cell
the new cell is given an electric shock which makes it divide into an embryo
once the embryo has developed it is inserted into the womb of a mother
what are benefits of genetic engineering
if a person has a faulty gene they may have a genetic disorder, the correct gene can be transferred so they are cured
several medical drugs have been produced such as insulin
GM crops have been developed
what are risks of genetic engineering
people are concerned about accidentally bringing new genes into wild flower populations
insects that arent pests may be affected by GM crops
concerns about eating GM crops on health
