Which of the following does not describe an aspect of the three-dimensional structure of the DNA helix?
A. The deoxyribose has the C-2' endo conformation, which defines the distance between adjacent phosphate groups.
B. The hydrophilic backbone of the alternating sugar and phosphate groups is on the outside of the helix.
C. The nearly planar and hydrophobic bases are stacked inside the helix relatively perpendicular to the backbone.
D. Additional stability is conferred by the hydrogen bonding between the complementary bases.
E. All of these choices correctly describe the structure of the DNA helix.
E
You might also like to view...
Sulfate-reducing bacteria are a ________ that are found in ________ environments
A) monophyletic group / anoxic B) polyphyletic group / oxic C) morphologically distinct group / anoxic D) morphologically distinct group / oxic
Pseudocoelomate nematodes lack a body cavity.
A. Incorrect; their body cavity is fully enclosed by ectoderm but is a functional body cavity. B. Correct; they are solid from the gut to the cuticle. C. Incorrect; although not fully enclosed by mesoderm the pseudocoel is a body cavity. D. Correct; their pseudocoel does not allow for the development and expansion of organs.
Which statement about chemoreceptors is NOT true?
A. Chemoreceptors are thought to be the most primitive sensory receptor to have developed in animals. B. Chemoreceptors are universally found in animals. C. Chemoreceptors are found all over the body surface in humans. D. Chemoreceptors are concentrated on the auricles of the head in planaria. E. Chemoreceptors are found on antennae and mouthparts in insects and other arthropods.
A selective medium contains one or more substances that inhibit growth of certain microbes in order to facilitate the growth of other microbes.
Answer the following statement true (T) or false (F)