Embryological Development

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Embryological Development

• Ch 38.2
• Page 698 Early Animal Development

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I 1.Development

• Cell division
• Growth
• Differentiation
• From embryonic tissues to
• Specialized tissues organs

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Embryological Development
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Meiosis in the Gonads
Sperm
Meiotic cell division
Egg
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2. Fertilization of egg in fallopian tube by
sperm
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3. Zygote formation

• Fertilized
• Egg
• 2n Chromo-some
• Union of sperm egg

1N Sperm
1N Egg
2N Zygote
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4.Implantation of egg in uterus
Fertilization
Implantation
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5. Cleavage Splitting by mitosis
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3rd Cleavage 8 balls

• cleave
• To cut
• Division of embryonic tissue
• From the zygote to a
• Multi-ball stage

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6.Blastula

• Hallow ball
• After cleavage
• Signals the onset of
• Differentiation of embryo

5th day blastocyst
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Hallow Ball or Blastula
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7. Gastrula

• Infolding of cells
• Follows
• Blastua stage
• Forms ?
• the digestive tract

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7.Differentiation

• differ
• Specialization of embryonic tissue
• Orders cells into tissues organs

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Experimental Studies
Cell Differentiation
Diffe
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Embryonic Development the gray crescent
Diffe
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9.Three cell layers
Ecto Skin nervous

• Ectoderm outer
• Mesoderm middle
• Endoderm inner

Meso Muscles Bones
Endo Digest. Bladder
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Neural Tube Development

• Neural nervous
• tube spinal column

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10-11.Mammal fetus uterus

• Placenta
• uterine lining
• Umbilical cordconnects to uterus
• Amnion sack with fluid
• Fetus baby

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Placenta Umbilical Cord
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Fetal Mothers Blood

• Mothers Blood is
• Separate from the baby!
• What passes across the placenta?
• Food, drugs, wastes, alcohol, oxygen
• What stays behind?
• Red blood cells
• How are wastes removed?
• Diffuse across the placenta (CO2, etc.)

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Marsupial Pouch
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Fetus Development
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4 Week Embryo
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Ultra sound scanning
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Amniocentesis

• Sampling the amnionic fluid
• Check for chromosome abnormalities