A great adaptive radiation of mammals began about
__________ million years ago.
a. 25
b. 65
c. 95
d. 125
e. 165
Answer: b
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When this exercise was written, the media campaign in support of golden rice was being launched. Search the Internet for the roots of the controversy over this genetically enhanced plant. Brie?y describe the bene?ts of, and the concerns over, its introduction to the rice-growing areas of the world.
What will be an ideal response?
What distinguishes expression vectors from other cloning vectors?
a. Expression vectors do not have an origin of replication. b. Only expression vectors have origins of replication. c. Expression vectors contain regulatory sequences to allow transcription and translation of an inserted gene. d. Inserted genes cannot be transcribed from an expression vector. e. Expression vectors do not contain antibiotic resistance genes.
Vertebrates that practice internal fertilization employ three strategies for embryonic and fetal development. In one strategy, the female retains the eggs within her body and the young are fully developed when they hatch inside of her. What is this called?
A. Oviparity B. Protandry C. Ovoviviparity D. Viviparity E. Protogyny
What most likely explains the recovery of live S strain cells from a mouse injected with heat-killed S strain mixed with live R strain cells?
a. The S strain was revived by the presence of the host's immune system. b. The R strain picked up the S strain DNA, enabling it to produce a capsule. c. The R strain cells picked up the capsules from the S strain cells. d. The S strain fused with the R strain, making it resistant.