*will mark brainliest to first correct answer* photosynthesis led to increasing levels during the later proterozoic eon? a. oxygen b. water c. carbon dioxide d. none of the above

oxygen: it was the result of biological activities. There were such stable continental shelf environments, which were rare in the Archean, developed after 2.5 billion years ago, facilitating the growth of photosynthetic organisms and thus oxygen production.

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)

it would be c. xylem.