Answer:
Since genetically engineered (GE) crops were introduced in 1996, their use in the United States has grown rapidly, accounting for 80-90 percent of soybean, corn, and cotton acreage in 2009. To date, crops with traits that provide resistance to some herbicides and to specific insect pests have benefited adopting farmers by reducing crop losses to insect damage, by increasing flexibility in time management, and by facilitating the use of more environmentally friendly pesticides and tillage practices. However, excessive reliance on a single technology combined with a lack of diverse farming practices could undermine the economic and environmental gains from these GE crops. Other challenges could hinder the application of the technology to a broader spectrum of crops and uses.
Explanation:
True both the ring of fire and island arcs are places with a lot of volcanoes
Answer:
Taking more samples from different parts of an acre.
Explanation:
Validity and accuracy of the data is crucial for any serious research. In this particular case, the most accurate data would be obtained if earthworms would be counted on the whole acre. Of course, this would consume lot of time, people, money etc. That's why methods for estimation are used. Estimation best works with large number of samples. Since one acre equals over 4000 square meters, taking only five samples from such a big area is simply not enough for obtaining valid data.
One of the possible ways to improve estimation is to take more samples per acre while avoiding taking adjacent samples because it could be possible that number of earthworms in one part of an acre is increased (or decreased) for any reason, which would lead us to wrong conclusion.
Answer:
Gene flow.
Explanation:
When individuals migrate, alleles can be transferred from one population to another population which is known as gene flow. Gene flow is also called gene migration, the introduction of genetic material through interbreeding from one population of organisms to another which changes the composition of the gene pool of the migrated population of organisms. This gene flow creates a new species that is different from previous population of organisms
Answer:
secrete a cytokine that triggers apoptosis
Explanation:
Cytotoxic T cells secrete granzymes and perforins when targeting cells. Additionally they secrete cytokines such as IFN-, TNF-α and TNF-β that act to activate macrophages and help kill infected cells.