Recombinant DNA Technology
Some genetic diseases cannot be diagnosed by changes in restriction sites. Some of these can be detected by allele-specific oligonucleotide probes. These are

short sequences that will hybridize only to a specific base sequence
mutagenized copies of a gene
copies of the gene with an altered sequence so that a restriction site is inserted
PCR-amplified variable numbers of tandem repeats (VNTRs)

ANSWER DOWNLOAD EXAMIANS APP

Recombinant DNA Technology
An example of a restriction fragment length polymorphism is

different length fragments of DNA resulting from loss or gain of a restriction site
cystic fibrosis results from a three base deletion in most cases but in other cases, other mutations are involved
an Eco RI cuts DNA at a different sequence than Hind III
All of these

ANSWER DOWNLOAD EXAMIANS APP

Recombinant DNA Technology
An expression vector

always contains an origin of replication
always contains DNA segments for the regulation of mRNA production
All of these
usually contains a gene that confers antibiotic resistance to the bacterial host

ANSWER DOWNLOAD EXAMIANS APP