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.
LINK / CITE ADD TO WORD LIST. noun. The definition of a chromosome is a thread-like structure of DNA (nucleic acids and proteins) that carries genes. The X or Y gene that determines whether you will be a boy or a girl is an example of a chromosome.noun. 1  A linear strand of DNA and associated proteins in the nucleus of eukaryotic cells that carries the genes and functions in the transmission of hereditary information.hromosome. noun. 1  A linear strand of DNA and associated proteins in the nucleus of eukaryotic cells that carries the genes and functions in the transmission of hereditary information.