It is possible, although uncommon, for two blue-eyed parents to have a brown-eyed child. This is due to the mutation of the HERC2 gene, which is responsible for blue eyes, and its relationship to the melanin-producing gene OCA2. Both must be functioning for the production of pigment.
A functioning HERC2 gene means that the OCA2 gene produces pigment if it is not already disabled through inheritance, thus ensuring that the child has brown eyes. Meanwhile, if the HERC2 is disabled but the OCA2 is not, the result is blue-eyed offspring. The opposite circumstances produce the same result. The relationship between these genes allows someone to be a carrier of the brown-eyes trait without having brown eyes.Learn More
The pyrimidine bases of DNA are cytosine and thymine. One pyrimidine combines with one purine to make up a rung of the DNA double helix. Nucleotides, the building blocks of DNA, comprise a phosphate group, a five-carbon sugar and either or a purine or a pyrimidine.Full Answer >
tRNA interprets the nucleotide sequence of mRNA to build the corressponding amino acid sequence. tRNA reads codons of mRNA to build proteins. tRNA does its job after the mRNA is made ready for translation.Full Answer >
Austrian monk Gregor Mendel discovered the principles of heredity that became the foundation of modern genetics. His experiments in his monastery's garden demonstrated the exchange of characteristics between pea plants.Full Answer >
Humans have 22 pairs of autosomes, or 44 autosomes in total. Autosomes are chromosomes that are not sex chromosomes (allosomes). Although humans have 23 pairs of chromosomes, only 22 of these are autosomes.Full Answer >