Many farmers now grow insect-resistant varieties of cotton. the gene for the favorable trait, in this case, insect resistance, is transferred to the cotton's dna using a) dna fingerprinting. b) tissue culture. c) bacterial plasmids. d) in vitro fertilization.

C bacterial plasmid

A plasmid is a small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA. Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes.

It can replicate in the cell separately . The desired gene(which codes for the desired trait) is inserted with this DNA molecule(plasmid) and tranfers to the host, where it gets replicate and helps in spreading the trait.

The insect resistent is caused in cotton in the same way. The gene for the resistant for insects is introduced into the bacterial plasmid which then transfers to the cotton. where it gets replicated and spread the resistance for insects.

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .