In the fossil record, there is evidence that feathers were produced by which of the following?
A. mammals
B. birds and some dinosaurs
C. birds and some mammals
D. birds
E. dinosaurs
B. birds and some dinosaurs
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Molecular clocks are based on _____ mutations
A. advantageous B. lethal C. deleterious D. neutral
Answer the following statements true (T) or false (F)
1. The Nernst Equation is: E = 60 mV log10 ([Xextracellular/Xintracellular]). Given this, the equilibrium potential for a given ion would be increased with an increase in its intracellular concentration. 2. Action potentials are typically also characterized as graded potentials. 3. Saltatory conduction is often studied in large marine invertebrates such as the giant squid. 4. The exposed, unmyelinated gaps between glia on myelinated axons are also sites of voltage-gated Na+ channels.
When an enzyme-catalyzed reaction reaches equilibrium
a. the enzymes are now inhibited. b. the chemical reactions cease. c. the rate of the forward and reverse reactions are equal. d. the concentration of reactants equals the concentration of products. e. ATP is no longer required to drive the reaction.
Roots and shoots lengthen through activity at _____
a. apical meristems c. vascular cambium b. lateral meristems d. cork cambium