#Question id: 28213
#Unit 5. Developmental Biology
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: 2946
#Unit 2. Cellular Organization
Which of the following occurs during anaphase A?
#Question id: 11180
#Unit 10. Ecological Principles
In contrast to herbivores,
#Question id: 10824
#Unit 10. Ecological Principles
Interspecific competition has been demonstrated experimentally in
#Question id: 4350
#Unit 3. Fundamental Processes
Portions of the DNA sequences of normal and mutant b-globin genes are shown. The most plausible explanation for why the indicated mutation (changing an A to a G) results in the disease b-thalassemia is that the mutation