Answer:
its being called a miracle because mules aren't supposed to give birth haha, they're sterile, they can't make sperm or eggs because their chromosomes don't match up well, and coz of chromosomes number.
Explanation:
for example they have 31 and horses have 32 pairs of chromosomes so they cant match with anythin
ATP is produced in the Calvin cycle
Summer's considered the best out of the 4 seasons because most people are on summer vacation and they are able to spend quality time with their family without all the snow or cold weather.
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.