With reference to the latest developments in stem cell research consider the following statements:1. The only source of human stem cells are the embryos at blastocyst stage.2. The stem cells can be derived without causing destruction to blastocysts.3. The stem cells can regnerate themselves in vitro virtually forever.4. Indian research centres also created a few cell lines which can be developed into many types of tissues. Which of the statements are correct?

Cell biology is a branch of biology that studies the structure, function, and behavior of cells. Cytology is the exam of a single cell type, as often found in fluid specimens.