do now: explain in your own words the changes that occur to chromosome number during fertilization
TRANSCRIPT
DO NOW:Explain in your own words the changes that occur to chromosome number during fertilization
The process of the fusion/uniting of the egg cell and the sperm cell
During fertilization …… the chromosome number is restored by a process called recombination
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Recombination is the additional mixing of genetic material from the sperm and the egg creating a UNIQUE combination
of genes
At this point the zygote has all needed chromosomes to be a human
Blastula
Cleavage
Zygote Blastula Gastrula
A hollow ball of cells
A three layered cluster of cells
Differentiationa.k.a. specialization
The process that transforms developing cells into specialized cells with different structures and functions
Before differentiation occurs, the cells are stem cells
an event in which the embryo adheres to the
wall of uterus. In order for the fetus to receive the oxygen and the nutrients from the mother to be able to
grow.
Fetal Life Support:
Includes:
Placenta
Amniotic sac
Umbilical cord
*Morphing embryo
Placenta:A flat organ that attaches to the inside of the uterus
and connected to the fetus by the umbilical cord.
Functions:• Transfer gasses• Transport nutrients• Excretion of wastes• Formation of a barrier
* The blood of the mother and the fetus do not mix
Human Fetus at 10 weeks
The Amniotic SacThe Amniotic Sac
•The fetus is in a fluid filled sac that helps protect it.
•When a woman’s “water breaks,” it means that this sac has ruptured
The umbilical cord (also called birth cord) is a tube that connects a developing embryo or fetus to the placenta.
Aim: How does a mother’s choices affect her offspring?
Prenatal development is greatly affected by anything circulating in the maternal blood
The Mother’s Choices Can Affect the FeWhat are some things that can affect
the fetus?s• Drugs
• Alcohol• Tobacco• Poor diet• Toxic substances• Infections (German measles, AIDS)
The Mother’s Choices Can Affect the Fetus
•The embryo is most susceptible to harm
during the first trimester
Alcohol abuse causes changes in the fetus called
fetal alcohol syndrome
•About 5% of newborns in the United States have a clinically significant birth defect, accounting for about 15% of deaths of newborns
Reproductive Technology:Reproductive Technology:
Amniocentesis:
**Reproductive Technology:Reproductive Technology:
• Hormone Regulation: to help women get pregnant
• In-vitro fertilization: Eggs are extracted from a woman’s ovaries and fertilize them with sperm in the laboratory. The fertilized eggs are then implanted in the uterus.
http://embryology.med.unsw.edu.au/
The Birth Process
Labor and Delivery
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