Spirogyra<span> is a genus of filamentous charophyte green algae of the order Zygnematales, named for the helical or spiral arrangement of the chloroplasts that is diagnostic of the genus.
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A cladogram is a diagram used to represent a hypothetical relationship between groups of animals, called a phylogeny.
In this set of examples the answer is:
D) The lamprey does not have a vertical column
Lampreys have a notochord that remains throughout life, but they have primitive vertebrae made of cartilage. Lampreys have vertebral arches, but nothing resembling the vertebral bodies found in all higher vertebrates. Even the arches are discontinuous, consisting of separate pieces of arch-shaped cartilage around the spinal cord in most parts of the body, changing to long strips of cartilage above and below in the tail region.
I think the correct answer from the choices listed above is option B. The difference in biodiversity between the tundra and the tropical rain forest would be that warmer temperatures and higher average rainfall in the tropical rainforest allow more things to survive. Hope this answers the question.
