Twins, says Dr. Judith G. ... Fraternal twins are known to arise when two eggs are released from the ovaries, get fertilized and implant together in the womb. In contrast, identical twins start out as a single embryo, split, and then develop as separate individuals in the womb.
All vascular plants have water-conducting tissue and are better adapted for life on land than the bryophytes; they are also characterized by a dominant sporophyte generation.
