A Norovirus can be considered as a 30 nm in diameter spherical particle, made of protein and DNA·The Noroviruses are known to be highly infective. As few as 10 viruses are enough to cause infection in a human. a) Suppose that an infected individual releases 5 cm3 of fluid containing 10% of Noroviruses by volume. Calculate the number of Noroviruses in this sample and the number of humans that could be infected with these viruses. What percentage of the human population on Earth (assumed 7 billion) could be infected? b) Could the virus spread around and infect all these humans only by diffusion? Calculate the diffusion coefficient and the time needed for one virus to diffuse to a length of 1 meter at 20°C (viscosity of water being 1.0x103 kg m s)?

Aresearcher has developed two stains for use with seed plants. one stains sporophyte tissue blue; the other stains gametophyte tissue red. if the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur? a) the pollen grains will be pure red.b) the pollen grains will be pure blue.c) the pollen grains will have red interiors and blue exteriors.d) the pollen grains will have blue interiors and red exteriors.

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

Asap brainliest will be which sentence about protists is accurate? all protists are unicellular and microscopic in nature. they have organelles, so protists are eukaryotic in nature. all protists make their own energy through photosynthesis.