All animals are
a) land-dwelling multicellular heterotrophs
b) capable of walking on legs
c) multicellular, heterotrophic and lack cell walls
d) unicellular or multicellular, heterotrophic and lack cell walls

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Match the type of adaptation to the correct example, structural adaptation functional adaptation behavioral adaptation example type of adaptation elephants live in herds to protect their young leaves of a rain forest plant species have a pointed tip that enables rainwater to drain off easily. camels have nostrils that they can close snakes produce venom to kill prey and defend themselves. earthworms coil when touched, as part of a defense mechanism. human skin darkens with increased exposure to sunlight.

The human genome project is devoted to mapping the general dna sequence of our species. this could lead to the development of new medicines, as well as the possibility of using gene therapy to treat certain diseases. however, there are some ethical issues surrounding the mapping of individual genomes. one concern is a) that your genes may change over time, making the project useless. b) that insurance companies could discriminate based on genetic make-up. c) that since this has never been done before, we should probably not do it now. d) that sequencing our individual genomes is so expensive, it is a counter-productive strategy.