Download How does one cell become a whole new organism?

How does one cell become a whole
new organism?
TOPIC: Embryonic Development and Prenatal
Care
Biology “Buzz”: Embryonic
Development
I. Before
Implantation
KEY IDEAS
 Development- the
changes that occur after
fertilization and
continues throughout
life.
 Ovum- an egg (ova is
plural!)
 Fertilization- union of
sperm and egg nuclei.
 Zygote- a fertilized egg.
Once fertilization occurs the zygote now begins the
amazing process of becoming a whole new organism.
This process starts and continues with cell division.
I.
Before
After ~8 days the embryo
implants into the uterus
and the cells will
differentiate into the
various cells of the body.
When cells differentiate into
various cells of the body, for
example…neurons, blood cells
and skin cells, these specialized
cells will give rise to different
body tissues, organs and organ
systems.
After Implantation
Embryonic Development
 Early human
development includes
the formation of
membranes that
surround, protect and
nourish the developing
embryo and by 8
weeks is known as a
fetus.
After Implantation
Embryonic Development
 The amnion forms a sac around
the embryo and contains
amniotic fluid to cushion the
growing embryo.
 The yolk sac provides early
nutrition and serves as an early site
for the formation of blood.
 The chorion helps to form the
placenta- the connection
between the mother and
developing embryo. The placenta
is the embryo’s organ of
respiration, nourishment, and
excretion.
 The umbilical cord connects the
embryo/fetus to the placenta.
 Fetal development is divided into trimesters, each lasting
about 3 months.
 Prenatal care, or care during pregnancy, ensures all goes
well with the developing fetus.
 Important things to pay attention to during pregnancy
include:
1. Nutrition and supplements such as calcium, iron, and folic
acid.
2. Plenty of fluids.
3. Exercise
4. Sleep
Analysis Questions…
1. What can we say is true about the genetic information in
each and every differentiated cell found in an embryo? WHY?
The genetic information or DNA is the same in every
cell because all cells have originally divided from one cell, the
zygote, by mitotic cell division.
2. If the DNA is the same in every cell, then how do cells
become specialized in function and structure?
Different parts of the DNA or different genes will
“turn on” as needed by the cell according to what function
each cell will have.
Reading for information…
Read “Some Things to Avoid” and answer the following
questions.
What are possible outcomes for a baby that has been exposed to…
 Alcohol
 Recreational drugs
 Nicotine
 Caffeine
 Over-the-counter and Prescription drugs.
Create a T-chart in your notebooks to record your notes!