With reference to the latest developments in stem cell research, consider the following statements:
- The only source of human stem cells are the embryos at blastocyst stage. –
- The stem cells can be derived without caisining destruction to blastocysts. –
- The stem cells can regenerate themselves in vitro virtually forever.
- Indian research centres also created a few cell lines which can be developed into many types of tissues.
Which of these statements are correct?