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Embryological Development. Ch 38.2 & Page 698 Early Animal Development. I 1.Development. Cell division Growth Differentiation From embryonic tissues to Specialized tissues & organs. Embryological Development. Meiosis in the Gonads. Sperm. Meiotic cell division. Egg.
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Embryological Development Ch 38.2 & Page 698 Early Animal Development
I 1.Development • Cell division • Growth • Differentiation • From embryonic tissues to • Specialized tissues & organs
Meiosis in the Gonads Sperm Meiotic cell division Egg
3. Zygote formation • Fertilized Egg • 2n Chromo-some # • Union of sperm & egg 1N Sperm + 1N Egg = 2N Zygote
4.Implantation of egg in uterus Fertilization Implantation
3rd Cleavage= 8 balls • “cleave” = • To cut • Division of embryonic tissue • From the zygote to a • Multi-ball stage
6.Blastula • Hallow “ball” • After cleavage • Signals the onset of • Differentiation of embryo 5th day blastocyst
Hallow Ball or Blastula
7. Gastrula • Infolding of cells • Follows • Blastua stage • Forms ? • the digestive tract
7.Differentiation • “differ” • Specialization of embryonic tissue • Orders cells into tissues & organs
Experimental Studies: Cell Differentiation Diffe
9.Three cell layers Ecto= Skin & nervous • Ectoderm= outer • Mesoderm= middle • Endoderm= inner Meso= Muscles Bones Endo= Digest. Bladder
Neural Tube Development • “Neural”= nervous • “tube” = spinal column
10-11.Mammal fetus & uterus • Placenta= uterine lining • Umbilical cord=connects to uterus • Amnion= sack with fluid • Fetus = baby
Fetal & Mother’s Blood • Mother’s Blood is • Separatefrom 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.)
Amniocentesis • Sampling the amnionic fluid • Check for chromosome abnormalities