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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23
46
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
Cleavage
Blastula
Zygote
Blastula
A hollow ball
of cells
Gastrula
A three layered
cluster of cells
Differentiation
a.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 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
Reproductive Technology:
Amniocentesis:
*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
• NOVA Online | Life's Greatest Miracle |
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