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UESTION 13 The mesoderm and endoderm was isolated from a gastrulating embryo. Th

ID: 196340 • Letter: U

Question

UESTION 13 The mesoderm and endoderm was isolated from a gastrulating embryo. These cels were dissociated the reaggregated mixed together). What would these cells do after reaggregation? The cells would self-sort such that mesoderm cells associate with other mesoderm cells and endoderm cells would associate with other endoderm cells The two cell types would separate from each other completely such that two separate groups of cells that are not touching would resulft The cels would change their cell fates such that inner cells would differentiate into endoderm and outer The two cell types would stay intermixed QUESTION 14 It epidermis from the wing of a chick embryo is placed on top of thigh mesenchyme what type of develop? structures will the epidermis Wing Feathers No structures will form Scales Thigh Feathers Click Save All Answers to save all ans

Explanation / Answer

Answer:

13. (a) The cells would self sort such that mesoderm cells associate with other mesoderm cells and endoderm cells would associate with other endoderm cells

Explanation:

In no case do the recombined cells remain randomly mixed, and in most cases, one tissue type completely envelops the other. The mesoderm also migrates centrally with respect to the gut or endoderm.

14. (d) Thigh feathers

Explanation:

Take epidermal epithelial wing cells and pieces of dermal mesenchyme from wing, thigh and foot (1 responder, 3 signals).

Wing mesenchyme + wing epidermal = feather

Thigh mesenchyme + wing epidermal = thigh feather

Foot + wing epidermal = scales and claws