What is the first step in the pressure flow mechanism of translocation?
A) Sugar is loaded into the xylem at the source.
B) Sugar is loaded into the phloem at the source.
C) Water is loaded into the phloem at the source.
D) Water is loaded into the phloem at the sink.
B
You might also like to view...
In some rocky intertidal habitats, the barnacle Chthamalus can survive across the same depths as can the barnacle Balanus
However, where the two occur together, Chthamalus adults are found only in the more stressful upper portions of the habitat where they are more prone to desiccation. This is an example of: A. the mutualistic form of symbiosis. B. intraspecific competition reducing the size of Chthamalus' fundamental niche to a smaller realized niche. C. mutualism reducing the size of Balanus' realized niche to a smaller fundamental niche. D. competitive exclusion reducing the size of Chthamalus' fundamental niche to a smaller realized niche. E. competitive exclusion expanding the size of Balanus' realized niche to a larger fundamental niche.
A friend is writing one of those “Animals Attack!” style movies, and needs your help choosing a species to fill the title role. The plot, to the extent that it can be called a plot, requires an organism that feasts on other animals with hard shells, and can sustain massive injuries only to come back stronger and in greater numbers. What species do you recommend?
a. bees b. turtles c. sea stars d. hydras
Feedback inhibition is a type of allosteric regulation in which a molecule binds to _______ and inhibits its _______.
a. a site on an enzyme distinct from the catalytic site; activity b. a site on an enzyme distinct from the catalytic site; synthesis c. the catalytic site on an enzyme; activity d. the mRNA for an enzyme; synthesis
A somatic cell from a corn plant normally contains 20 chromosomes. How many sister chromatids would that cell contain during G2 of the cell cycle?
A. 20 B. 10 C. 40 D. 0