one of the biggest advanatges of gentically engineered bacteria is they can
make exactly the protiens needed andf in very pure form .
what can geenitically enegineered genes be used for
to improve growth rates of planst and animals
to improve the food value of crops and to reduce the fat levels in meat
they are used to produce plants which make their own pesticides
what are the advantages of GM crops
they may be genetically engineered so that they are resistant to herbicide meaning a farmer can srpary his weeds without killing his crops
GM crops increase the yeild of a crop , making more food
people living in LEDC'S often lack nutrients in their diet and GM crops could be conatin the nutrients that are missing
what are the disadvanatges of GM crops
the GM crop seeds may be expensive for farmers
pollination may mean that if GM crops are nearby weeds the gene for herbicide resistance may be transfered to the weeds
we dont know wheter eating GM crops over a long period of time will cause health problems
what are the ethical issues of genetic engineering
humans may not have the right to gentically alter nature for their convinience and profits in some peoples opinions
vegetarians may find it offensive to put animal genes into plants
most cells in your body have a nucleus . the nucleus conatins
your genetic material in the form of chromosomes
the human cell contains ..... pairs of .....
23
chromosomes
chromosomes carry
genes . different genes control the devlopment of different characteristics
a gene is a short length of the chromosome which is quite a long length of ......
DNA
sexual reproduction involves the
fusion of of male and fema tle gametes . Because there are two parenst , the offspring contain a mixture of their parents genes
in asexual reproduction there is only :
one parent . there's no fusion of gametes , no mixing of chromosomes and no genetic variation between parent and offspring , the offspring are genetically identical to the parent - they are clones
how does asexual reproduction work
X shaped chromosmes have two identical halfs
so each chromosome splits down the middle
to form two identical sets of half chromosomes (i.e. two identical sets of DNA strands)
a membrane forms around each set
and the DNA replicates itself to form two identical cells with complete sets of X shaped chromosomes