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: 4639

#Unit 11. Evolution and Behavior

If the HMS Beagle had completely bypassed the Galapagos Islands, Darwin would have had a much poorer understanding of the

#Question id: 4640

#Unit 11. Evolution and Behavior

During drought years on the Galapagos, small, easily eaten seeds become rare, leaving mostly large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, what should one expect to result from natural selection?

#Question id: 4641

#Unit 11. Evolution and Behavior

Which of the following statements is an inference of natural selection?

#Question id: 4642

#Unit 11. Evolution and Behavior

Which of Darwinʹs ideas had the strongest connection to Darwin having read Malthusʹs essay on human population growth?

#Question id: 4643

#Unit 11. Evolution and Behavior

The treeʹs horizontal axis is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V—Z) represent various common ancestors. Letʹs say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.

How many separate species, both extant and extinct, are depicted in this tree?

#Question id: 4644

#Unit 11. Evolution and Behavior

The treeʹs horizontal axis is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V—Z) represent various common ancestors. Letʹs say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.

According to this tree, what percent of the species seem to be extant (i.e., not extinct)?