In eukaryotic gene regulation, RNA interference occurs through:

A. the accumulation of mRNA that blocks transcription of the target gene by feedback inhibition.

B. the action of microRNAs that block translation of specific mRNA molecules.

C. the action of RNA–protein complexes that degrade the regulatory proteins responsible for initiating transcription.

D. the accumulation of mRNA that blocks transcription of nearby genes.

In the family tree below, people with the recessive trait of attached earlobes are shaded gray.

The tasmanian devil, a marsupial carnivore, is facing extinction due to devil facial tumor disease (dftd) which causes bulging cancerous lumps and lesions to erupt around the face and neck — often causing enough deformation to make seeing or eating difficult. dftd has evolved into a contagious cancer, a trait that is unique among cancers. devil mating behavior involves biting around the head and neck, allowing cells from one individual — especially cells from the crumbly dftd tumors — to be transferred to the wounds or face of a new individual. this marsupial was once found across australia, but sea levels rose, isolating the tasmanian population, while the australian population went extinct. what would be an outcome of genetic isolation that is likely to have impacted the spread of dftd? a) reduced territory puts diseased individuals in greater contact with non-diseased ones. b) inbreeding results in less variation in facial features so the cancer is generally fatal. c) genetic isolation has made it difficult for scientists to develop a vaccine against dftd. d) the lack of genetic variation in the immune system of tasmanian devils minimizes resistance to the disease.

Which locations on the map are low-pressure areas? a b c d e