Plants and algae most recently shared a common ancestor 480 million years ago, and plants colonized land shortly after that. In sexual reproduction, an alga simply releases gametes into the water, and the current carries the sex cells to another individual. What adaptation did plants have to make in reproduction when they moved to dry land?
a. Development of stomata
b. Development of vascular tissue
c. Production of a cuticle
d. Production of pollen
e. Production of lignin
Answer: d. Production of pollen
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Which of the following biotechnology applications of site-specific recombination deletes DNA from the target?
A. gene activation by removing a transcriptional stop site B. gene insertion C. allele replacement D. gene activation by adding an enhancer sequence E. gene repression by disrupting transcription with an insertion.
Like bacteria, yeasts grow easily in culture. But why are they regarded as more useful for recombinant DNA technology?
a. They are more stable in culture than prokaryotes because they are not prone to bacteriophages. b. They are virtually harmless to humans so they are less risky to work with than prokaryotes. c. Because yeasts are eukaryotic, they exhibit post-transcriptional mRNA editing not performed by any prokaryotes such as Escherichia coli. d. They have longer lifespans so they do not have to be split and recultured as often.
All but which factor were important evolutionary adaptations in primates?
a. enhanced stereoscopic vision b. upright position c. an opposable thumb d. the development of a restricted or specialized diet e. brain expansion and elaboration
Planarians lack dedicated respiratory and circulatory systems because _____
A) none of their cells are far removed from the gastrovascular cavity or from the external environment B) they lack mesoderm as embryos and, therefore, lack the adult tissues derived from mesoderm C) their flame bulbs can carry out respiratory and circulatory functions D) their body cavity, a pseudocoelom, carries out these functions