英和和英

名詞

polyembryony (uncountable)

1. (botany) The production of two or more embryos in one seed, due either to the existence and fertilization of more than one embryonic sac or to the origination of embryos outside of the embryonic sac.
   • 2012, B. M. Johri, Embryology of Angiosperms, ISBN 3642693024, page 447:

     By its nature, that is whether it develops with or without fertilization, simple polyembryony can be sexual or asexual.

   • 2014, Kishan Gopal Ramawat, ‎Jean-Michel Mérillon, & ‎K. R. Shivanna, Reproductive Biology of Plants, ISBN 1482201321, page 356:

     Polyembryony was first reported by Leeuwenhoek in citrus as early as 1719 and the different cases of polyembryony were studied by Braun in 1859.

2. (biology) The production of two or more embryos from a single fertilized egg.
   • 1989, Roger Neville Hughes, Functional Biology of Clonal Animals, ISBN 0412331306, page 90:

     In all these groups cloning, where it occurs, must be through polyembryony or parthenogenesis.

   • 2005, Roger E. Stevenson & ‎Judith G. Hall, Human Malformations and Related Anomalies, ISBN 019974808X, page 1381:

     Despite their utility in research, litters produced by polyembryony lack the advantages conferred by either asexual or sexual reproduction.

   • 2014, John C. Avise, Genetics in the Wild, ISBN 1588344290:

     One form of clonal reproduction begins when a fertilized egg divides a few times in the womb before initiating embryonic development. In humans, this can lead nine months later to the birth of identical (monozygotic) twins. This phenomenon, known as polyembryony, occurs sporadically in many mammal species. However, only in armadillos does polyembryony happen consistently, in each and every pregnancy.