How to Grow Butter Leaf Lettuce. Butter lettuce is a loose-leaf lettuce with a mild flavor. Lettuce is a cool-weather crop, grown across the U.S. in the spring and fall when temperatures are moderate. Butter lettuce, a loose-leaf type of lettuce, may be more tolerant of hot temperatures than some other varieties. In maritime climates with cool summers, lettuce may be grown in the summer, fall and late winter. Inland, where temperatures rise in the summer, lettuce may be grown in late winter and fall.
Humans have 23 pairs of chromosomes, one half of each pair inherited from each parent. The Y chromosome is small, carries few genes, and has abundant repetitive sequence, while the X chromosome is more autosome-like in form and content.
Females typically have two X chromosomes (46,XX), and males have one X chromosome and one Y chromosome (46,XY). 47,XYY syndrome is caused by the presence of an extra copy of the Y chromosome in each of a male's cells.As a result of the extra Y chromosome, each cell has a total of 47 chromosomes instead of the usual 46.7,XYY syndrome is characterized by an extra copy of the Y chromosome in each of a male's cells. Although males with this condition may be taller than average, this chromosomal change typically causes no unusual physical features.