Predation arose in prokaryotic organisms, increasing the complexity of interactions among organisms through their ability to engulf particulate food
A. true
B. false
B
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Which of the following is NOT a product of the light reaction?
A. NADPH B. ATP C. oxygen D. carbon dioxide E. energy intermediates
A selective growth medium
A. allows only certain bacteria to grow. B. allows all bacteria to grow. C. allows no bacteria to grow. D. accentuates differences between the growing bacteria.
Ctenophores and Cnidaria both have nerve and muscle cells, but Ctenophores lack Hox genes that occur in both Cnidaria and Porifera. What is the most likely explanation?
a. Porifera diverge from a common ancestor before nerve and muscle cells evolved, then Cnidaria and Ctenophores absorbed viral genomes containing Hox genes from plasmids contained within their environment. b. Hox genes were deleted from the Ctenophore genome after Ctenophores diverged from a common ancestor with Cnidaria, and Porifera developed nerve and muscle cells. c. Hox genes developed in a common ancestor of Cnidaria and Porifera after it diverged from an ancestor in common with Ctenophores, then nerve and muscle cells developed via parallel evolution. d. Hox genes are produced by mitochondria; Porifera lack mitochondria, and therefore cannot contain Hox genes. The presence of nerve and muscle cells is entirely unrelated and irrelevant.
When G2 and M phase cells were fused together, the G2 nucleus became prematurely compacted when it was exposed to S phase cytoplasm in the fused cell. The G2 chromosomes could be seen to be visibly doubled. What conclusion was drawn from this result?
a) M phase cytoplasm contained diffusible factors that initiate DNA synthesis b) G2 nuclei cannot respond to diffusible factors present in M-phase cell cytoplasm c) the cytoplasm of the mitotic cell contained diffusible factors that could induct mitosis in a non-mitotic cell d) the cytoplasm of the G2 cell contained diffusible factors that could halt mitosis in a mitotic cell