Compare and contrast cyclic and noncyclic photophosphorylation
What will be an ideal response?
Both cyclic photophosphorylation and noncyclic photophosphorylation are aspects of the light-dependent reactions of photosynthesis. They both involve the excitation of electrons by light energy; these excited electrons then participate in an electron transport pathway to create a proton gradient that can be used to produce ATP through chemiosmosis. However, as its name implies, cyclic photophosphorylation occurs when electrons return to the chlorophyll molecules whence they came. Excited electrons in noncyclic photophosphorylation are also used in the same way to produce ATP; however, these electrons are donated to an NADP+ molecule at the end of their transport chain, producing NADPH as a product of the system. Because electrons are constantly leaving the chlorophyll molecules where they are being excited, and not returning, there must also be a steady source of electrons for the photosystem. These electrons can come from molecules such as water or hydrogen sulfide.
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The Ngorongoro Conservation Area is an example of ____
a. conservation through preservation, with people completely excluded b. conservation through preservation, with people allowed only as temporary visitors c. mixed use conservation, with some human residents and livestock grazing d. mixed use conservation, with no human residents and limited livestock grazing e. conservation through restoration, with efforts to remove contaminants underway
In the Meselson-Stahl experiment, DNA containing one heavy and one light strand was observed after
one generation of growth in media containing light nitrogen. If they had not allowed a second generation of growth, what would these scientists have been able to conclude?
What will be an ideal response?Independent assortment of homologous chromosomes occurs at
A. anaphase I. B. anaphase II. C. metaphase I. D. interphase. E. prophase I.
The number of genes correlates with _____.
a) the size of the genome in prokaryotes b) and is approximately equal to the number of different proteins that a species can make c) being much higher among Eubacteria than in Archaea d) the size of the genome in eukaryotes e) being higher in Archaea than in eukaryotes