an elderly woman in a nursing home no longer goes outside to enjoy the sunshine and fresh air, has reduced her meat intake because her dentures don't fit well, and has recently been having difficulty concentrating on conversations with others. she may be developing a deficiency of which vitamins?

The body is protected against harmful flu viruses by

Spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

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.