Chromosome 21

The Mendel Medal is awarded to outstanding scientists who have done much by their painstaking work to advance the cause of science. Demonstrating that between true science and true religion there is no intrinsic conflict.

Mendel’s work marked the beginning of genetics as a science. Nucleic acids and genes – originally two widely separated concepts – together form the basis for this year’s Nobel Prize for medicine, for Holley’s, Khorana’s and Nirenberg’s investigations on the genetic code, also called the code of life.

Gregor Mendel, through his work on pea plants, discovered the fundamental laws of inheritance. He deduced that genes come in pairs and are inherited as distinct units, one from each parent. Mendel tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits.

Chromosome 1 is the designation for the largest human chromosome. Humans have two copies of chromosome 1, as they do with all of the autosomes, which are the non-sex chromosomes. Chromosome 1 spans about 249 million nucleotide base pairs, which are the basic units of information for DNA.

The X and Y chromosomes, also known as the sex chromosomes, determine the biological sex of an individual: females inherit an X chromosome from the father for a XX genotype, while males inherit a Y chromosome from the father for a XY genotype (mothers only pass on X chromosomes).

DMD, the largest known human gene, provides instructions for making a protein called dystrophin. This protein is located primarily in muscles used for movement (skeletal muscles) and in heart (cardiac) muscle. Small amounts of dystrophin are present in nerve cells in the brain.

Thus the mccA gene encodes the peptidic chain of MccC7. To our knowledge, mccA is the smallest gene so far reported.

Paris japonica

Since the onion (Allium cepa) is a diploid organism having a haploid genome size of 15.9 Gb, it has 4.9x as much DNA as does a human genome (3.2 Gb).