Though some of the research is inconclusive, identify the findings about biological factors and their effect on sexual orientation as either true or false.
mothers who have already given birth to one boy may develop an immune reaction when pregnant with another boy, which alters the hormones in the prenatal environment.
females who were exposed to androgens while in the womb are more likely to report being lesbians.
gay men have higher levels of estrogen, and lesbian women have higher levels of testosterone.
researchers have found a single gene in humans that, when altered, causes people to reverse their sexual orientation.
there is an area of the hypothalamus that is smaller in gay men than it is in straight men.
identical twins are more likely than fraternal twins to have the same sexual orientation.

From a high concentration to a low concentration.

answer: carbon 14 can only be used to determine the age of the organisms that were once living, and igneous rocks are non living.

explanation:

carbon 14 dating is used to determine the age of the sample by estimating the amount of carbon 14 present in the sample and then comparing it with a reference standard.carbon 14 is a isotope of carbon which is radioactive and unstable. carbon 14 is assimilated by all plants and animals throughout their life from carbon dioxide. however, one the organisms die they stop this assimilation and the carbon 14 content starts to decrease.by knowing how much of carbon 14 is left in an organism after his death, one can estimate the age of the organism. the materials whose age can be estimated by carbon 14 method are the organic compounds. however, some inorganic compounds such as aragonite   shell can also be dated.however, if we consider the igneous rocks it is a non living component which never accumulated carbon 14 in it and thus, we cannot use carbon 14 dating method to estimate its age.