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Development Study Guide
Human Development Lab Assignment
A). Structure of sperm
2). Secondary oocyte:
offspring inherit mitochondrial DNA from their mothers.
After meiosis only one cell contains almost all of the cytoplasm and organelles.
The sperm does not bring in any cytoplasm or organelles
Thus offspring inherit mitochondria (& mitochondrial DNA) from their mothers.
II). How does the sperm penetrate the secondary oocyte?
Immediately after fertilization
sperm loses tail
secondary oocyte undergoes meiosis II
(meiosis I occurred during the female’s fetal development)
eject polar body
female pronuclei & male pronuclei
form a mitotic spindle
produce a diploid zygote.
Stages of Development
|V). Zygote Development
|Blastocysts differentiates into
VI). Embryonic Membranes
develop during gastrula
A). What prevents the normal sloughing off of the uterine wall?
The endometrium the villi forms the placenta.
|VII). Fetal Circulation|
Blood cells arise in the yolk sac
spaces appear in mesoderm
(middle germ layer)
heart, blood vessels, etc.
by 3.5 weeks heart is formed and beating
1. Umbilical vein (to the heart) transports oxygen rich blood from the placenta to the fetus
2. Blood enters the liver and the ductus venous that shunts blood to the vena cava
3. Most of the blood is than shunted from the right atrium to the left atrium bypassing the pulmonary arteries and lungs.
4. The opening between the atriums of the heart is called the foramen ovale
5. Blood in the pulmonary trunk enters the aorta-bypassing lungs at the ductus arteriosus
6. Blood in the descending aorta branches off into the umbilical arteries and to the placenta