The plant hormones known as ___________ may have an evolutionary origin in the common ancestor to both plants and animals.
A. brassinosteroids
B. oligosaccharides
C. cytokinins
D. auxins
E. abscisic acids
A. brassinosteroids
The similarity between brassinosteroids are structurally similar to animal steroid hormones. This suggests and evolutionary origin the predates the animal-plant split.
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In many soils there is more than enough phosphorus to support plant growth, but it is tightly bound to soil particles and thus largely unavailable. Which of the following are potential solutions to this problem for vascular plants?
(Select all correct answer options.) A. form symbiotic relationships with mycorrhizae B. form symbiotic relationships with bacteria C. pump H+ into the soil D. raise soil pH
Because of the mechanism of sex determination, males of many species can be neither homozygous nor heterozygous. Such males are said to be ________
A) dominant B) complementary C) hemizygous D) recessive E) None of the answers listed is correct.
Disseminated intravascular coagulation (DIC) is a complication resulting from the
A) release of cytotoxins. B) triggering of the complement system. C) attachment of bacterial cells to the endocardium. D) release of heme from damaged RBCs. E) release of lipid A from dying Gram-negative bacteria.
Porin proteins form large, barrel-like channels in the membrane. Which of the following is not true about these channels?
(a) They are made primarily of ? helices. (b) They are made primarily of ? sheets. (c) They cannot form narrow channels. (d) They have alternating hydrophobic and hydrophilic amino acids.