Barbara McClintock examined the mechanism for the appearance of purple spots in the kernels of yellow and white corn. She attributed the spots to: A new type of fungus Insertion of a genetic element into the Pr allele of heterozygous corn (Prpr) Insertion of a genetic element into the CI allele of heterozygous corn (CIC) Insertion of a genetic element into the pr allele of heterozygous corn (Prpr) Insertion of a genetic element into the C allele of heterozygous corn (CIC)

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

relative humidity, temperature and dew point -- are bound together in the mathematical relationship below. relative humidity changes when temperatures change. because warm air can hold more water vapor than cool air, relative humidity falls when the temperature rises if no moisture is added to the air. so i would say a

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".