The membrane bound organelle you refer to is the Lysosome. The lysosome fuses with a vacuole where it digest the contents.
The correct answer is: Replacement of defective genes with normal genes
Recombinant DNA molecules are made in laboratory by the methods of genetic recombination such as molecular cloning. The aim of these methods is to bring together genetic material from different sources, creating “combinations” that usually couldn’t be found in the genome. The process of recombination is possible because, DNA molecules from all organisms share the same chemical structure (nucleotides are same among different species, difference is only in the nucleotide sequence).
The arctic environment is deathly cold, hence the thick blubber on animals so they can handle freezing temperatures
