The peterson family has three boys. if mrs. peterson is pregnant with her fourth child, what is the probability that this child will be a girl?

Aheterozygous normal male marries a woman with a sickle cell anemia. give the genotypes and possible phenotypes of the offspring

Which member of the following food chain will be least affected by ddt, a pesticide water pollutant, if bio-magnification is occurring? algae> zooplankton> crayfish> leopard frog> large mouth bass

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of