You and your lab partner have isolated 20 new mutant yeast strains that are defective in synthesis of threonine, an amino acid. These Thr- mutants do not grow on minimal medium, but they do grow on minimal medium supplemented with threonine. Ten of your Thr- mutants (numbered 1 through 10) were isolated in a strain of mating type a (MAT a). The other 10 Thr mutants (numbered 11 through 20) were isolated in a strain of mating type α (MAT α). You and your lab partner cross each of the MAT a strains to each of the MAT α strains, and you include crosses to the appropriate wild-type strains. Your experimental observations are shown in the table below, where (-) indicates diploids that did not grow on minimal medium and (+) indicates diploids that did grow on minimal medium.

Which mutations are recessive?

#Question id: 4628

#Unit 11. Evolution and Behavior

Which group is composed entirely of individuals who maintained that species are fixed (i.e., unchanging)?

A) Linnaeus

B) Lyell

C) Darwin

D) Aristotle

E) Cuvier

#Question id: 19984

#Unit 2. Cellular Organization

#Question id: 5039

#Unit 5. Developmental Biology

The process by which developing cells achieve their functional, mature identity as liver, or muscle, or nerve is called:

#Question id: 1523

#Unit 4. Cell Communication and Cell Signaling

Following statements are regarding to the apoptosis which is induced by trophic factors.

A. The presence of specific trophic factors (e.g., NGF) leads to activation of their cognate receptor tyrosine kinases (e.g., TrkA) and activation of the PKB pathway.

B. DNA damage or ultraviolet irradiation leads to induction of synthesis of the BH3-only Puma protein. Puma binds to Bak and Bax as well as to Bcl-2, allowing Bak and Bax to form oligomeric pores.

C. Removal of a cell from its substratum disrupts integrin signaling, leading to release of the BH3-only Bim protein from the cytoskeleton.

D. Binding of extracellular death signals, such as tumor necrosis factor and Fas ligand, to their receptors oligomerizes an associated protein (FADD), which in turn triggers the caspase cascade, leading to cell murder by apoptosis.

Which of the following pathway does not belong to the trophic factor inducing apoptotic pathway?

#Question id: 7035

#Unit 5. Developmental Biology

In xenopus, In what conditions b-catenin on target gene expression without wnt protein?