Fertilization/conception
First cell division occurs ___ hours after chromosome fusion
12
How long will egg wait to be fertilized?
12-24 hours
Conception-
2 cells (egg + sperm) join together to make one cell
Conception is possible every
28 days
Cell division repeats
3 days, every 12-15 hours
Sperm survive up to
5 days
The fertilized egg is called a blastocyst after
5 days, inside the uterus
The journey from vagina to Fallopian tube is
6-7 inches, takes several hours
Blastocyst has
60-70 cells, 4th day
implantation occurs
8 days after fertilization
Blastocyst
Attaches to uterine wall (implantation)
unfertilized egg
Begins to disintegrate + die
Sperm head travels to nucleus of ovum and the
Chromosomes combine
Where is the ova fertilized?
Fallopian tube
Zygote/germinal stage is the
First two weeks post conception
Sperm genetic material is in the
Head
____ out of ____ sperm reach the egg
Hundreds out of millions
Result of egg's death
Large quantities of progesterone sent into blood, cueing uterine lining to be shed
Once sperm as penetrated the egg, it's tail
Separates from the head, dies
identical twins
Single egg, divided + fertilized
Sperm genetic material
Spreads out to form nucleus. M+F nuclei join together
When a sperm breaks through egg wall
The chemical structure of the egg changes to shut out remaining sperm
Zygote
The fertilized egg
Pregnancy in the Fallopian tube
Tubal pregnancy
fraternal twins
Two fertilized eggs
First cell is called the
Zygote
embryo
the developing human organism from about 2 /3 weeks after fertilization through the second month
