The circulatory system - hemoglobin in the blood transports oxygen :)
The gene which is produced once or twice in a lifetime is the milk producing hormone after childbirth. This is because it is produced only after the birth of the child. The growth of the mammary glands takes place during pregnancy. The breast continue to increase in size after giving birth to a child. After delivery only copious milk is produced which is generally done with the help of milk hormone. During pregnancy the secretion of the milk is inhibited by the estrogen and progesterone which circulates in the blood stream which in turn inhibits the release of prolactin from the pituitary gland thus making the mammary glands unresponsive. Where as insulin is a hormone which helps the body to utilise the sugar or glucose from different sources like carbohydrates that we get while we eat food and adrenaline is secreted when we are scared or when we feel that we are in danger. Therefore, milk producing hormone is the gene that are turned once or twice in a lifetime.
Insulin controls blood sugar by lowering it, glucagon tells the liver to release its stored sugar into the blood stream, increasing blood sugar.
<span>tRNA - Transfer RNA: Brings amino acids to ribosomes during translation.
rRNA - Ribosomal RNA: With ribosomal proteins, makes up the ribosomes, the organelles that translate the mRNA.
<span>snRNA - Small nuclear RNA: With proteins, forms complexes that are used in RNA processing in Eukaryotas. (Not found in prokaryotes.)</span></span>
