Tara Rodden Robinson

Many milestones define the history of genetics. The events in the world of genetics are listed here roughly in order of historical occurrence. ©Nasky/Shutterstock.com The publication of Darwin’s The Origin of Species Earthquakes have aftershocks — little mini-earthquakes that rattle around after the main quake.

Transgenic critters (genetically modified organisms) are all over the place. Animals, insects, and bacteria have all gotten in on the fun. In this article, you take a trip to the transgenic zoo to learn a little bit about the menagerie. Transgenic animals Mice were the organisms of choice in the development of transgenic methods.

One of the hottest topics these days is gene editing (also known as genome editing). Gene editing is a group of genetic engineering technologies that allow scientists to change a specific sequence within the genome. Each of these technologies involves an engineered enzyme called a nuclease, which can cut DNA, along with some kind of guide to lead the enzyme to the right place in the genome.

If genetic modification is so ubiquitous, what’s the problem with transgenic organisms? After all, humans have been at this whole genetic modification thing for centuries, right? Well, historically, humans have modified organisms by controlling matings between animals and plants with preexisting genetic compatibility, not by introducing sequences from different species.

Genetics is a field that grows and changes with every passing day. This list shines the spotlight on ten of the hottest topics and next big things in this ever-changing scientific landscape. ©Dusan Petkovic/Shutterstock.com Direct-to-consumer genetic testing Not too long ago, genetic testing was uncommon and was reserved for visits to a geneticist, genetic counselor, or other specialized healthcare provider.

DNA is made up of long chains of nucleotides. To make a complete DNA molecule, single nucleotides join to make chains that come together as matched pairs and form long double strands. Each nucleotide is comprised of the following: A five-sided (pentose) sugar called deoxyribose A phosphate One of four nitrogen-rich bases: adenine, guanine, cytosine, or thymine Nucleotides are joined together by phosphodiester bonds.

Genetic inheritance boils down to three simple concepts put forth by Gregor Mendel, a humble monk and part-time scientist who founded the entire discipline of genetics: Segregation: In diploid organisms, chromosome pairs (and their alleles) are separated into individual gametes (eggs or sperm) to transmit genetic information to offspring.

If you could open the nucleus of a cell and peek inside, you’d find chromosomes — the strands of DNA where genes reside. This figure helps you see how all the parts of a chromosome relate to one another.