Specification of different mesodermal cell types in the frog Xenopus laevis by activin, a paracrine factor of the TGF-beta family. Which of the following observation is correct at the high concentration of activin?

#Question id: 7123

#Unit 5. Developmental Biology

In chicks, the formation of the neural tube relies on what cell biological processes?

#Question id: 7007

#Unit 5. Developmental Biology

The change in the state of specification of imaginal disc of Drosophila to that of a different disc type is known as:

#Question id: 11284

#Unit 10. Ecological Principles

Which of the following could qualify as a top-down control on a grassland community?

#Question id: 11096

#Unit 7. System Physiology – Animal

In which structure does diffusion of oxygen to capillaries not play a major role?

#Question id: 7244

#Unit 5. Developmental Biology

Following statements are regarding to the evolutionary conservation of homeotic gene organization and transcriptional expression in fruit flies and mice.

A. In fruit flies and mice genes with similar structures occupy the same relative positions on each of the four chromosomes, and paralogous gene groups display similar expression patterns.

B. Hom-C cluster on Drosophila chromosome 3 and the four Hox gene clusters in the mouse genome are similar and evolutionary conserved.

C. Those mammalian genes homologous to the Drosophila labial, proboscipedia, and deformed genes are expressed anteriorly and early, whereas those genes homologous to the Drosophila AbdB gene are expressed posteriorly and later.

D. In fruit flies and mice genes are orthologous Hox gene groups.

E. Those mammalian genes homologous to the Drosophila labial, proboscipedia, and deformed genes are expressed posteriorly and later, whereas those genes homologous to the Drosophila AbdB gene are expressed anteriorly and early.

Which of the following combination is correct?