Go to the following website and use it to fill in the following blanks: http://w

Question

Go to the following website and use it to fill in the following blanks:

http://www.discoverdevelopment.com/PHP/SlidesStarfish.php (Links to an external site.)Links to an external site.

Look at the following slides, determine the stage of each starfish embryo and name the structures shown by the arrows.

A shows the_______ stage; B shows the________ stage; C shows the _________stage and D_______ stage.

E shows the________ , F the __________ , G the ________ , H the ________, I the  and J the _________

The starfish is a                            [ Select ]                       ["deuterostome", "holoblast", "meroblast", "protostome"]         , which means the structure shown in E will become the                            [ Select ]                       ["anus", "mouth"]      

Explanation / Answer

A shows the Early Gastrula stage; B shows the Mid Gastrula stage; C shows the Morula stage, and D is zygote stage. E shows the Blastopore, F is the Ectoderm, G is the Blastocoel; H the Blastomeres, I the Fertilization membrane, J the archenteron

The starfish is a Deuterostome which means the structure shown in E will become the an_us

Explanation:

Zygote stage: Shortly after fertilization, the vitelline membrane of the egg cell membrane is converted to fertilization membrane. It helps in prevention of polyspermy and serves as a difference between the fertilized and unfertilized egs

Morula Stage: During the early period of cleavage, just as seen in the 16 and 32 celled stage,s the blastomeres are packed together like a cluster of mulberries and the embryo is referred to as the morula

Early gastrula: In echinoderms like Starfish, the first sign of gastrulation is the flattening of the blastula at the vegetal pole. This flattened region then gradually folds inward, converting the spherical blastula into a cup shaped gastrula

Mid gastrula: During mid gastrula stage, the blastocoel is displaced and a new cavity, the archenteron, is formed. The opening into the archenteron is the blastopore and develops into the an_us in all deuterostomes

Related Questions

Navigate

• Browse (All)
• Browse G
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.