Embryonic Development

Lab

Miss School, Miss Out!

Honors Human Biology 5-6

Lab 40

Question: How do the various stages of animal development compare to one another?

Hypothesis: None for this lab.

Procedure: View prepared slides of starfish, pig, and chicken embryos.

Observations: Take pictures, measure, and record the magnification for the following: zygote, 2-cell, 4-cell, morula, blastula, and gastrula stages. Label the ectoderm, endoderm, and mesoderm on the gastrula. Take pictures of the 48-hour chicken and the 10mm pig embryos making 5 observations and note two similarities for each.

Analysis: At what stage does the embryo implant? List the fate of the ectoderm, endoderm, and mesoderm.

Statement of Significance:

Embryonic Development Lab

40x = 25 μm 100x = 10 μm 400x = 2.5 μm 1000x = 1.0 μm

Stage Magnification Size

zygote

2 cell

4 cell

morula

blastula

gastrula

Lab 40 Label Requirements

Star Fish Embryos

1. 2-cell stage

2. 4-cell stage

3. blastomere

4. blastula

5. gastrula

6. morula

7. zygote

Blastula

1. blastocoel

Gastrula

1. archenteron

2. blastopore

3. ectoderm

4. endoderm

5. mesoderm

10mm Pig Embryo/48 hour Chicken Embryo

1. heart

2. somites

Star Fish Embryos

1. 2-cell stage

2. 4-cell stage

3. blastomere

4. morula

5. zygote

Star Fish Embryos

1. blastula

2. gastrula

Blastula

1. blastocoel

Gastrula

1. archenteron

2. blastopore

3. ectoderm

4. endoderm

5. mesoderm

10mm Pig Embryo/48 hour Chicken Embryo

1. heart

2. somites

10mm Pig Embryo/48 hour Chicken Embryo

1. heart

2. somites

END

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