Fgf10 is function as positive feedback factor in different ways such as___

a) to maintain the activation of both Wnt2b and Tbx5

b) to tells the surface ectoderm to continue to make Fgf8, and the surface ectoderm continues to tell the underlying mesoderm to make Fgf10

c) to maintain the activation of both Wnt3a and Tbx4

d) to tell the mesenchyme cells directly beneath it to continue making Fgf10

#Question id: 23696

#Unit 13. Methods in Biology

#Question id: 26493

#Unit 3. Fundamental Processes

#Question id: 5673

#Unit 5. Developmental Biology

Species-specific sperm attraction has been documented in numerous species. In echinoderms, sperm are attracted toward eggs of their species by chemotaxis. Following statements are about chemoattraction-

A. In this process Sperm follows a gradient of a chemical secreted by the egg.

B. These oocytes control only the type of sperm they attract, but not the time at which they attract them.

C. Releasing the chemotactic factor only when the sea urchin egg has completed all of its meiotic divisions .

D. Releasing the chemotactic factor only when the sea urchin egg is in second metaphase of its meiotic division.

E. The mechanisms of chemotaxis differ among species and chemotactic molecules are different even in closely related species.

Which of the following statement are incorrect about this process?

#Question id: 19084

#Unit 4. Cell Communication and Cell Signaling

#Question id: 31344

#Unit 12. Applied Biology