The concentrations of ions are very different inside and outside a nerve cell due to ________.

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#Question id: 5019

#Unit 11. Evolution and Behavior

A major evolutionary episode that corresponds in time most closely with the formation of Pangaea was the

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#Question id: 8927

#Unit 9. Diversity of Life Forms

Arthropods invaded land about 100 million years before vertebrates did so. This most clearly implies that

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#Question id: 11740

#Unit 6. System Physiology – Plant

Some given characteristics of the two types of sieve elements in seed plants such as Sieve tube elements and Sieve cells. Find out the  true characteristics of sieve tube elements from the given statements;

i) Found in angiosperms

ii) Sieve plate pores are open channels

iii) Albuminous cells sometimes function as companion cells

iv) P-protein is present in all eudicots and many monocots

v) There are no sieve plates; all sieve areas are similar

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#Question id: 11934

#Unit 7. System Physiology – Animal

Which of the following represents the basis for transduction of a sensory stimulus into nerve impulses?

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#Question id: 12181

#Unit 2. Cellular Organization

Following statements are regarding to the CFTR.

A. cystic fibrosis transmembrane conductance regulator allows Cl− ions to flow out of the cell, following their concentration gradient.

B. ATP binding to CFTR’s two nucleotide-binding domains appears to close the Cl− channel, and the hydrolysis of one ATP opens it (the other ATP remains intact).

C. the CFTR channel can open only if its regulatory domain (which is unique among ABC transporters) has been phosphorylated, thus regulating the flow of ions across the membrane.

D. The maintenance of electrical neutrality requires that the Cl− ions transported by the CFTR be accompanied by positively charged ions, mainly Na+. The transported ions are osmotically accompanied by water, thus maintaining the proper level of fluidity in secretions of the airways, intestinal tract, and the ducts of the pancreas, testes, and sweat glands.

Which of the following combination is correct?