In many plant and animal communities that are found on islands, the number of species (S) changes with the area (A) of the island as follows: S = cAz, where 0 <z < 1 and c>0. Which of the following graphs best represents such a species-area relationship?

#Question id: 31152

#Unit 2. Cellular Organization

#Question id: 28824

#Unit 2. Cellular Organization

Vertebrate skeletal muscle contraction, also depends on set of specialized accessory proteins that is troponin, which is closely associated with the actin thin filaments. Troponin is a complex of three polypeptides except;

#Question id: 9569

#Unit 10. Ecological Principles

#Question id: 723

#Unit 1. Molecules and their Interaction Relevant to Biology

Common structural elements in proteins such as α-helices or β-sheets are characterized by uniformly repeating, energetically favorable main chain conformations which additionally exhibit a completely saturated hydrogen-bonding network of the main chain NH and CO groups. Although polyproline or polyglycine type II helices (PPII or PGII ) are frequently found in proteins, they are not considered as equivalent secondary structure elements. Which of the following statements are correct about PP and PGs.

A. PGII -like helices form hexagonal bundles which appear to fulfill the criterion of a (largely) saturated hydrogen-bonding network of the main-chain groups

B. main chain NH and CO groups of the central PGII -helix are saturated by either intra- or intermolecular hydrogen-bonds, resulting in a self-contained hydrogen-bonding network

C. The formation of the right-handed PPI helix is possible only with proline residues because of the required cis conformation. 

D. PPII helices seem to be stabilized by main chain-water hydrogen bonds (in the absence of main chain- main chain H-bonds), and tend to have a regular pattern of hydrogen bonds with water. After this, it is not surprising, that PPII helices are found mostly on the protein surface.

#Question id: 11124

#Unit 9. Diversity of Life Forms

A researcher compared the nucleotide sequences of a homologous gene from five different species of mammals with the homologous human gene. The sequence homology between each speciesʹ version of the gene and the human gene is presented as a percentage of similarity.

What probably explains the inclusion of rabbits in this research?