Ddt is a synthetic compound commonly used as an insecticide. it was used to control mosquito species that commonly spread diseases like malaria. the data show the percent resistance for three species of mosquitoes over three decades. what explains the trend seen in the data? a) genetic drift resulted in the random deaths of non-resistant insects, leaving only resistant mosquitoes to breed. b) artificial selection favored genotypes that were bred by humans to maintain the desired traits in the mosquito populations. c) gene flow between the three species increased the genetic diversity of the populations, resulting in more ddt-resistant species over time. d) natural selection favored resistant members of the species, which survived and reproduced at a greater frequency than non-resistant mosquitoes. el

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation:

i won't lie i don't know so go online and ask google thats what i do