When they were first sold, certain insecticides were highly effective in killing mosquitoes. today, dozens of mosquito generations later, a much smaller proportion of these insects die when sprayed with the same chemicals. fewer insects are killed today because

a. mosquitoes are deliberately adapting themselves to this man-made change in the environmentb. mosquitoes that survive spraying develop an immunity to the insecticidec. many mosquitoes today are descendants of mosquitoes with insecticide-resistant characteristicsd. the original spraying has caused a permanent mutation, giving the insects genetic resistance to the spray

__1__ is a climate cycle where the temperature of the __2__ ocean changes because of movements of air and ocean currents. during this period, the trade winds in the south __3__ , causing the __4__ water to move from the __5__ region to the __6__ region. 1) el nino or the monsoon 2) atlantic, indian, or pacific 3) reverse, strengthen, or weaken 4) cold or warm 5) eastern or western 6) eastern or western

(drag each tile to the correct identify which questions can be answered by what can be answered by science or which cannot. -is it right or wrong to use genetic engineering to produce new food products? -what are the most common social settings that tend to produce accomplished artists? -if a new gene is added to the genome of a tomato species, will that species be more resistant to insects? -should humans use biotechnology to bring extinct organisms from the fossil record back to life? -do the types of organisms found in the fossil record appear in consistent sequences in different parts of the world? -are michelangelo's paintings more impressive than rembrandt's?

What causes darkening of the skin as melanin production increases