Y Chromosome
One of the sex chromosomes that has the genetic information to produce male offspring, that is accompanied by chromosome X. Some inherited characteristics in offspring (such as hairy ears and colour blindness in men) are believed to be sex linked, I.e. in.
Y Linked
Genes that are on the Y chromosome, and therefore "Y" linked because the resultant phenotype is a result of this Y linked gene.
Yeast
Pertaining to organisms used in industry due to the advantageous enzymes that they secrete to catalyse a particular chemical reaction. Yeast is responsible for the creation of alcohol.
Yellow Fever
A disease occurring frequently in the tropical areas of the world where ample conditions are available for the disease to occur. The disease is responsible for attacking the major organs in humans, namely the endocrine system and the kidneys, which can prove deadly if untreated. The mosquito species Aedes aegypti is responsible for the transmission of the disease between to new human carriers, and does so by sucking the blood of an infected human and transmitting it by contaminating another human with contact of the infected blood deriving from the host.
Yolk
The part of eggs that contains nutrients, primarily consisting of protein and fat molecules which provide the basic building blocks of life. Evolutionary change has resulted in changes in mammal eggs, where the embryo obtains food from the placenta as opp.