Development lab
Download
1 / 15

Development Lab - PowerPoint PPT Presentation


  • 63 Views
  • Uploaded on

Development Lab. Biology 113. Yolk Distribution. Isolecithal Telolecithal. Holoblastic versus Meroblastic cleavage. Holoblastic cleavage , the complete division of the egg occurs in species whose eggs have little or moderate amounts of yolk, such as sea urchins and frogs

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Development Lab' - doyle


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Development lab

Development Lab

Biology 113


Yolk distribution
Yolk Distribution

  • Isolecithal

  • Telolecithal


Holoblastic versus meroblastic cleavage
Holoblastic versus Meroblastic cleavage

  • Holoblastic cleavage, the complete division of the egg occurs in species whose eggs have little or moderate amounts of yolk, such as sea urchins and frogs

  • Meroblastic cleavage, incomplete division of the egg occurs in species with yolk-rich eggs, such as reptiles and birds




Sea star development
Sea Star Development

  • Identifiable stages are:

  • ovum, an unfertilized egg; nucleus and nucleolus are visible

  • zygote, a fertilized egg (diploid); the nucleus is not visible

  • 2 cells, the product of mitosis of the zygote, cells size is halved

  • 4 cells

  • 8 cells


Sea star development1
Sea Star Development

  • Identifiable stages are:

  • morula (like a compact cluster of grapes)

  • blastula, a hollow ball of cells—early, middle, and late stages are determined by cell size, which gets smaller with each round of mitosis


Sea star development2
Sea Star Development

Gastrula in which the surface pushes into the interior at a point called the blastopore to form a tube that will become the digestive system.

In a gastrula the cells on the outside are ectoderm, those lining the inner tube are endoderm, and cells that migrate and multiply between these layers will become the mesoderm.


Unincubated chicken egg
Unincubated Chicken egg







ad