Multiple couples living in a small village in the eastern african lowlands, all of whom are heterozygous for the hbs allele, have 500 children among them. of these children, 139 are homozygous for hba, 279 are heterozygous for hbs, and 82 suffer from sickle cell disease. are these data statistically significant? explain using a chi-square statistical analysis test.

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection

Ras is a g-protein that is activated when a growth factor attaches to egfr. its activation results in the replacement of a gdp molecule with a gtp molecule, thus allowing a signal transduction pathway to be activated. considering the signal pathway illustrated on this page, what is one potential outcome of a mutation in the ras gene that leads to ras protein hyperactivity. be specific.

How do disease caused by bacteria and disease caused by viruses react to antibiotics