#Question id: 26942
#Unit 10. Ecological Principles
#Question id: 13141
#Unit 10. Ecological Principles
Five similar populations of a herbaceous annual plant are monitored for three years; then, the numbers of individuals in populations I-IV are increased by an experimenter. Subsequent changes in the sizes of all the populations are shown in the graph below.
If size distributions of individuals do not vary among these populations, which of the following relationships best illustrates the occurrence of population regulation?
#Question id: 9190
#Unit 9. Diversity of Life Forms
What is the probable role of salicylic acid in the defense responses of plants?
#Question id: 1374
#Unit 4. Cell Communication and Cell Signaling
Following statements are regarding to gap junctions.
i. Vertebrate gap junctions are composed of connexins, a family of structurally related transmembrane proteins with molecular weights between 26,000 and 60,000.
ii. Each vertebrate hexagonal particle consists of six noncovalently associated connexin molecules. Each individual connexin molecule has two membrane-spanning α helices with a topology similar to that of claudin.
iii. The permeability of gap junctions is regulated by posttranslational modification of connexins (e.g., phosphorylation) and is sensitive to changes in environmental conditions
such as intracellular pH and Ca2+ concentration, membrane potential, and the intercellular potential between adjacent interconnected cells (“voltage gating”).
iv. The assembly of connexins, their trafficking within cells, and the formation of functional gap junctions apparently depend on N-cadherin and its associated adapter proteins as well as desmosomal proteins.
Which of the following statements are correct?
#Question id: 12105
#Unit 10. Ecological Principles