Introduction: Sexual reproduction is the formation of offspring that are genetically distinct from their parents; most often, two parents contribute genes to their offspring. Among most eukaryotes, sexual reproduction …
A useful tool for analyzing genetic crosses is the testcross, in which one individual of unknown genotype is crossed with another individual with a homozygous recessive genotype for the …
Mendel started with 34 varieties of peas and spent 2 years selecting those varieties that he would use in his experiments. He verified that each variety was genetically pure …
The cell cycle is the life story of a cell, the stages through which it passes from one division to the next. The cell cycle consists of interphase (a …
Like prokaryotic cell reproduction, eukaryotic cell reproduction requires the processes of DNA replication, copy separation, and division of the cytoplasm. However, the presence of multiple DNA molecules requires a …
The term gene was a word that Mendel never knew. It was not coined until 1909, when the Danish geneticist Wilhelm Johannsen first used it. The definition of a …
In 1902, the basic principles of genetics, which Archibald Garrod successfully applied to the inheritance of alkaptonuria, had just become widely known among biologists. Surprisingly, these principles had been …
Although the science of genetics is young — almost entirely a product of the past 100 years — people have been using genetic principles for thousands of years. Prehistory: …
Although the science of genetics is relatively new, people have understood the hereditary nature of traits and have “practiced” genetics for thousands of years. The rise of agriculture began …
On August 12, 1904, Tsar Nicholas Romanov II of Russia wrote in his diary: “A great never-to-be forgotten day when the mercy of God has visited us so clearly.” …