When did the first eukaryotic cells form?
A. 2.1 billion years ago
B. 2.1 million years ago
C. 2.1 thousand years ago
D. 3.7 billion years ago
Answer: A
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Which naturally occurring plant hormone has a major role in the phototropic response of plants?
A. Ethylene B. Auxin C. Abscisic acid D. Gibberellin E. 2, 4-D
What is the role of the urethra?
a) to transport urine out of the body b) to transport the egg to the uterus c) to connect the kidneys to the bladder d) to connect the uterus to the outside of the body
Once an endosymbiotic relationship was established between a bacteria and a eukaryotic cell, what effect did it have on their genomes?
a. The eukaryotic genome lost some genes whose function could be supported by the bacteria but the bacterial genome did not change. b. Both genomes evolved so that eventually the host and the bacteria became incapable of living independently. c. The bacteria transferred all of its DNA to the eukaryotic nucleus. d. The bacteria lost its genome and relied solely on the eukaryotic cell. e. The endosymbiotic relationship did not affect either cell's genome.
Which of the following is a characteristic seen in prophase I that does NOT occur in prophase II?
A) Chromosomes move to the middle of the cell. B) Spindle formation occurs. C) The number of chromosomes doubles. D) Crossing over occurs.