One method to clone a mammal involves nuclear transfer, in which a somatic cell
One method to clone a mammal involves nuclear transfer, in which a somatic cell nucleus from a donor mammal is transferred to a recipient egg cell with its nucleus removed. This method results in a few live births overall due to a high prevalence of developmental abnormalities. Notably, the probability of a live birth is significantly greater for embryos cloned from the nuclei of undifferentiated embryonic stem cells than for embryos cloned from the nuclei of differentiated somatic cells (Rideout et al., 2001).Select the best explanation of why embryos cloned from undifferentiated embryonic stem cells have greater developmental success than embryos cloned from differentiated somatic cells: a) Somatic cells are older than stem cells and have accumulated mutations that disrupt normal embryonic development. b) Embryos not formed from the fusion of a sperm and egg lack genomic imprinting, which increases the likelihood of abnormal embryonic development. c) Patterns of epigenetic markers are different in stem cells and somatic cells, with stem cells having epigenetic patterns more closely associated with early development. d) Patterns of epigenetic markers in stem cells and somatic cells are identical, indicating that the observed difference is not due to epigenetic regulation of development. e) Long non-coding RNA transfers with the donor nucleus, which represses expression of autosomal genes important to embryonic development.