In the first part of the twentieth century, there was much speculation of the cause of Down syndrome. The first people to speculate that it might be due to chromosomal abnormalities were Waardenburg and Bleyer in the s. But it wasn't until that Jerome Lejeune and Patricia Jacobs, working independently, first determined the cause to be trisomy triplication of the 21st chromosome. Cases of Down syndrome due to translocation and mosaicism see definitions of these below were described over the next three years.
9 Foods that Cause Inflammation and 9 Ways to Fight it
9 Foods that Cause Inflammation and 9 Ways to Fight it « Solluna by Kimberly Snyder
Genetics is the branch of biology concerned with the study of the DNA of organisms, how their DNA manifests as genes, and how those genes are inherited by offspring. Genes are passed to offspring in both sexual and asexual reproduction, and over time natural selection can accumulate variations amongst individuals on the group level, in the process known as evolution. Ancient peoples from around the world recognized that a child inherited their appearance and propensity for certain personality traits from their parents, though could not demonstrate the mechanism without modern knowledge of atoms, molecules, and biochemistry. During the 4 th century, BC Aristotle wrote several texts regarding the origin and history of animals, making numerous astute observations regarding the degree of relatedness between animals that would not be significantly expanded upon until the sixteenth or seventeenth centuries. He would also have purported the ancient Greek theory of the four humors, these being one of the few aspects that might be passed from parents to children. The circumstances of conception and development were thought significantly more critical to the resulting traits of the child up until the end of the eighteenth century, and until Charles Darwin, in the mid-nineteenth, for heredity to emerge as a central problem in biology.
Anti-LGBT rhetoric are themes, catchphrases , and slogans that have been used against homosexuality or other non-heterosexual sexual orientations in order to demean lesbian , gay , bisexual , and transgender LGBT people. They range from the demeaning and the pejorative to expressions of hostility towards homosexuality which are based on religious , medical, or moral grounds. It is a form of hate speech   which is illegal in countries such as the Netherlands,  Norway,  and Sweden. Anti-LGBT rhetoric often consists of moral panic or conspiracy theory. In Eastern Europe, these conspiracy theories are based on earlier antisemitic conspiracy theories and posit that the LGBT movement is an instrument of foreign control and domination.
Submissions are now open, via the link at the bottom of this page. HHMI BioInteractive: Genetics Engage your students in a discussion about traits — both physical and personality- and the factors that influence them. This lesson plan encourages students think like a scientist and to design an experiment and present it to their classmates for feedback.