Human Embryonic Development and Life Beginning Views

Monozygotic Identical Twins

Twins with identical genetic makeup, developing with shared or separate structures.

Pre-embryo

Stage before day 12 where individuality is not fixed, allowing for twinning.

Viability View

Belief that human life starts when the entity can survive independently from the mother.

Trimester

Three-month period in human pregnancy, often used for legal distinctions.

Monozygotic Twinning

Process of embryo division before primitive streak, producing identical twins.

Metabolic View

Perspective stating life begins at conception, considering sperm and egg as living organisms.

Neurological View

Defines human life beginning with the acquisition of EEG, allowing mid-trimester abortions.

Life begins at birth

Concept stating human life starts when the baby is born and independent from the mother.

Fertilization

Process starting with sperm-ovum contact, resulting in a zygote with 46 chromosomes.

Zygote

Result of fertilization, not an egg, with combined sperm and ovum chromosomes.

Mitosis

Cell division process in zygote forming blastomeres for future organism.

Morula

Cluster of 12-16 blastomeres from zygote before blastocyst stage.

Blastocyst

Hollow cellular ball at 30 blastomeres, with inner cell mass developing into embryo.

Trophoblast

External capsule of smaller cells in blastocyst, forming the placenta.

Primitive Streak

Marking on blastocyst after implantation, developing into the spinal column.