A cross is made between two parents, both with genotype Aa. What is the probability that an offspring will have the genotype aa?
O 1/8
O 1/4
O 1/2
O 3/4

a few examples of ethical concerns involving genetically engineering of humans include

-privacy of genetically tested people

- potential side effects

-long term effects

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".

c. heat from the poles back down towards the equator.