. Principles of modern biology. Biology. But regardless of how they develop, they carry the same genes and are therefore Always of the same sex — two boys or two girls FRATERNAL TWINS Are products of TWO different eggs fertilized by TWO different sperms They have different genes and may develop in different ways, usually— but not always — having separate placentas and separate fetal sacs. Also, as they are totally different in- dividuals, they may be. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appe
. Principles of modern biology. Biology. But regardless of how they develop, they carry the same genes and are therefore Always of the same sex — two boys or two girls FRATERNAL TWINS Are products of TWO different eggs fertilized by TWO different sperms They have different genes and may develop in different ways, usually— but not always — having separate placentas and separate fetal sacs. Also, as they are totally different in- dividuals, they may be. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marsland, Douglas, 1899-. New York, Holt, Rinehart and Winston
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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectbiology
