The children in a middle school classroom are all exposed to chicken pox one week. Among these students are John, who had chicken pox when he was much younger, and Sara, who has never had chicken pox. Which student do you expect would be less likely to become ill with chicken pox following this exposure and why? John: he has naturally acquired active immunity to chicken pox from his previous exposure. Sara: she has naturally acquired passive immunity to chicken pox from exposure to other students. John: the pathogens that cause chicken pox will no longer be able to enter his body. Sara: since she has not suffered from chicken pox, her immune system is probably stronger than John’s.

Examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. polyploidy is creating new species. the two populations are not interbreeding freely. hybrid offspring of the two populations begin to appear. one species will increase into a population size twice as large as the other species.

Abnormal softening of a gland is known as

Aparent with freckles is crossed with a parent without freckles. the punnett square shows the possible genotypes and phenotypes of the offspring. which statement accurately describes the probability of phenotypes? a.the offspring are more likely to have freckles. b.the offspring are more likely to have no freckles. c.the likelihood of the offspring having freckles and not having freckles is the same. d.the likelihood of the offspring having freckles and not having freckles cannot be determined.