5.Living organisms on Planet Earth range in size from very small (e.g., bacteria) to very large (e.g., blue whales). There is approximately a 3 million fold difference in size between the two. Yet the cells that comprise the organisms on Earth are all roughly the same size, i.e., 10 – 50 um (a 5 fold difference), regardless of whether the organism is a bacterium, a blue whale, or anything in between.
Explain why this is the case. In other words, why are large organisms composed of trillions of small cells, rather than just one big cell?
In composing your answer, think about these considerations when comparing a small single celled organism to a large multicellular one:
1. Specialization of cells according to their functions in the organism
2. Transport of materials in to and out of cells.
11.Global warming is having a catastrophic impact on the biology of the earth. This is due in large part to the combustion of fossil fuels. Although many of the forecasts based on models predict gloomy outcomes for the planet, there are some glimmers of hope. Indicate at least 5 developments now under way giving optimism about resolving the climate change crisis before it is too late to save the planet.
12.Linnaeus was the first to organize life forms according to phylogeny (evolutionary history). The most useful part of his naming system has become known as the Latin binomial.
1. What two phylogenetic terms make up the Latin binomial for any given organism?
2. The binomial for humans is homo sapiens. Write this binomial in proper scientific form (any of several variations will be acceptable, as long as they are not incorrect)
3. With the advent of molecular biological techniques, what has become the most accurate, and universally accepted, technique for classifying organisms?
17.Humans have been genetically modifying plants and animals for the last 13,000 years. The technologies for doing this have been based on transferring pollen to stigmas in plants or combining egg and sperm in animals. Within the last 30 years it has become possible to genetically modify any organism using molecular technology. There has been concern in some quarters that the use of molecular technology is riskier than conventional breeding.
1. Why is molecular technology, based on manipulation of a cloned gene, actually safer than conventional breeding, based on combining two complete genomes?
2. Use of any breeding technology results in production of candidates intended for commercialization. By what criterion should any candidate be judged?