Hwang Woo-suk, a geneticist in South Korea, claimed in Science magazine in 2004 and 2005 that he and a team of researchers had for the first time cloned a human embryo and that they had derived eleven stem cell lines from it. Hwang was a professor at Seoul National University in Seoul, South Korea. In the Science articles, Hwang stated that all of the women who donated eggs to his laboratory were volunteers who donated their eggs (oocytes) without receiving any compensation in return. In 2006, Hwang admitted that many of the results were fabricated. Subsequent investigations found that Hwang's lab used more eggs than they had accounted for in their experiments, and that egg donors had been paid. Hwang's use of donated eggs in his experiments attracted international attention and sparked debates about the ethics of egg donation for research purposes.

Angelman syndrome is a disorder in humans that causes neurological symptoms such as lack of speech, jerky movements, and insomnia. A human cell has two copies of twenty-three chromosomes for a total of forty-six-one copy from its mother and one from its father. But in the case of Angelman syndrome, the maternal chromosome numbered 15 has a mutation or deletion in its DNA and a gene on the paternal chromosome 15 is inactivated in some parts the brain. The result is the paternal gene is silenced during development of the sperm, which is called genetic imprinting. Angelman syndrome was one of the first disorders described as caused by genetic imprinting.

In the early twentieth century, scientists and agriculturalists collected plants in greenhouses, botanical gardens, and fields. Seed collection efforts in the twentieth century coincided with the professionalization of plant breeding. When scientists became concerned over the loss of plant genetic diversity due to the expansion of a few agricultural crops around mid-century, countries and organizations created seed banks for long-term seed storage. Around 1979, environmental groups began to object to what they perceived as limited access to seed banks, and they questioned the ownership of the intellectual property of living organisms. Controversy also ensued over the uneven flow of genetic resources because many of the seed banks were located in the global North, yet plants were collected largely from countries in the global South. The environmental groups' campaigns, which some called the seed wars, and the movement for biodiversity conservation intersected in ways that shaped debates about plant genetic material and seed banking. Several significant shifts in governance occurred in 1994 that led to the creation of the International Plant Genetic Resources Institute in Italy, and to changes in the governance of several international seed banks.

In Stenberg v. Carhart, the US Supreme Court ruled on 28 June 2000 that a Nebraska law banning partial birth abortions was unconstitutional. Though the US Supreme Court case Roe v. Wade in 1973 had set a precedent that constitutionally protected abortions, some states established limitations on certain types of abortion procedures. When NebraskaÕs state government criminalized partial birth abortions, physician LeRoy Carhart challenged the constitutionality of the case. Don Stenberg, an Attorney General located in Lincoln, Nebraska, represented the state of Nebraska. Stenberg determined that states could not create undue burden on womenÕs right to terminate their pregnancies, and that specific restrictions on abortion procedures must include an exception to protect a womanÕs health and life.

Barbara McClintock worked on genetics in corn (maize) plants and spent most of her life conducting research at the Cold Spring Harbor Laboratory in Laurel Hollow, New York. McClintock's research focused on reproduction and mutations in maize, and described the phenomenon of genetic crossover in chromosomes. Through her maize mutation experiments, McClintock observed transposons, or mobile elements of genes within the chromosome, which jump around the genome. McClintock received the Nobel Prize for Physiology or Medicine in 1983 for her research on chromosome transposition. McClintock's work helped explain the behavior of chromosomes in organismal development and identified transposition as a cause of genetic variation.

Nikolai Ivanovich Vavilov proposed theories of plant genetic diversity and participated in the political debate about genetics in Soviet Russia in the early twentieth century. Vavilov collected plant species around the world, building one of the first and most comprehensive seed banks, and he spent much of his life researching plant breeding and genetics. Vavilov also developed a theory of the historical centers of origin of cultivated plants. Vavilov spent most of his scientific career in Russia, although he studied abroad and traveled extensively. The ascent of geneticist Trofim Lysenko, favored by Joseph Stalin, and Vavilov's public criticism of him lead to Vavilov's arrest in 1940 and his death in prison three years later.

John Craig Venter helped map the genomes of humans, fruitflies, and other organisms in the US in the late 1990s and early 2000s, and he helped develop an organism with a synthetic genome. In February 2001, Venter and his team published a human genome sequence after using a technique known as Expressed Sequence Tags, or ESTs. Venter worked to bridge commercial investment with scientific research. Venter founded a number of private companies, including the for-profit Celera Genomics, headquartered in Alameda, California, as well as research institutes, such as the not-for-profit J. Craig Venter Institute, located in Rockville, Maryland, and La Jolla, California.

The Human Genome Project (HGP) was an international scientific effort to sequence the entire human genome, that is, to produce a map of the base pairs of DNA in the human chromosomes, most of which do not vary among individuals. The HGP started in the US in 1990 as a public effort and included scientists and laboratories located in France, Germany, Japan, China, and the United Kingdom. Scientists hypothesized that mapping and sequencing the human genome would facilitate better theories of human development, the genetic causes and predispositions for a number of diseases, and individualized medicine. The HGP, alongside the private effort taken up by the company Celera Genomics, released a working draft of the human genome in 2001 and a complete sequence in 2003. The history of the HGP ripples beyond biomedical science and technology into the social, economic, and political.

Francis Sellers Collins helped lead the International Human Genome Sequencing Consortium, which helped describe the DNA sequence of the human genome by 2001, and he helped develop technologies used in molecular genetics while working in the US in the twentieth and twenty-first centuries. He directed the US National Center for Human Genome Research (NCHGR), which became the National Human Genome Research Institute (NHGRI), of the US National Institutes of Health (NIH), located in Bethesda, Maryland, from 1993 to 2008. Collins led teams of researchers to use data on human genomes to investigate the genetic aspects of diseases and treatments, the variations among people in terms of their DNA sequences, and the evolution of humans. Collins became director of the NIH in 2009. Some criticized him for his Christian faith and its possible impacts on science funding through the NIH, such as for stem cell research, cloning, and embryonic genetic testing. As a director of the NHGRI and the NIH, Collins helped shape the structures and aims of projects in biology that pursue what he called big science, and he helped relate those projects to federal governments and to private companies.

Boris Ephrussi studied fruit flies, yeast, and mouse genetics and development while working in France and the US during the twentieth century. In yeast, Ephrussi studied how mutations in the cytoplasm persisted across generations. In mice he studied the genetics of hybrids and the development of cancer. Working with George Wells Beadle on the causes of different eye colors in fruit flies, Ephrussi's research helped establish the one-gene-one-enzyme hypothesis. Ephrussi helped create new embryological techniques and contributed the theories of genetics and development.