Each father and mother pass down traits to their children, who inherit combinations of their dominant or recessive alleles. But how do we know so much about genetics today? Hortensia Jiménez Díaz explains how studying pea plants revealed why you may have blue eyes.
Gregor Johann Mendel (July 20, 1822 – January 6, 1884) was a German-speaking Silesian scientist andAugustinian friar who gained posthumous fame as the founder of the new science of genetics. Mendel demonstrated that the inheritance of certain traits in pea plants follows particular patterns, now referred to as the laws of Mendelian inheritance. The profound significance of Mendel's work was not recognized until the turn of the 20th century when the independent rediscovery of these laws initiated the modern science of genetics.
In the 1850s and 60s, in a monastery garden in Burno in Moravia, a Franciscan monk was cultivating peas. He began separating the wrinkly peas from the shiny peas and studying which characteristics were passed on when the next crop of peas were grown. In this slow and systematic way Gregor Mendel worked out the basic law of heredity and stumbled upon what was later to be described as the fundamental unit of life itself…the gene.
The Punnett square is a diagram that is used to predict an outcome of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach and is used by biologists to determine theprobability of an offspring's having a particular genotype.
Dominance in genetics is a relationship between alleles of a gene, in which one allele masks the expression (phenotype) of another allele at the same locus.
In genetics, a recessive gene is an allele that causes a phenotype (visible or detectable characteristic) that is only seen in a homozygous genotype (an organism that has two copies of the same allele) and never in a heterozygous genotype.
Here's a list of TED Talks about genetics.
Your body is made of cells -- but how does a single cell know to become part of your nose, instead of your toes? The answer is in your body's instruction book: DNA. Joe Hanson compares DNA to detailed manual for building a person out of cells -- with 46 chapters (chromosomes) and hundreds of thousands of pages covering every part of you.
Nobel laureate James Watson opens TED2005 with the frank and funny story of how he and his research partner, Francis Crick, discovered the structure of DNA.
From something as small and complex as a chromosome to something as seemingly simple as the weather, sex determination systems vary significantly across the animal kingdom. Biologist and teacher Aaron Reedy shows us the amazing differences between species when it comes to determination of gender.
What do a man, a mushroom, and an elephant have in common? A very long and simple double helix molecule makes us more similar and much more different than any other living thing. But, how does a simple molecule determine the form and function of so many different living things?