Genetic engineering: Britain experiment may one day lead to genetically modified humans

Researchers aim to understand fertility issues using CRISPR, a genome editing tool, to modify genes. This involves using RNA to replace faulty DNA with healthy DNA in embryos, which are observed over seven days. Critics warn this could lead to genetically modified humans.

Explain the monitoring process of embryos after genome editing as described in the text.

What are the potential ethical concerns raised by critics regarding genetically modified humans?