Can we conclude that President Thomas Jefferson could have fathered Sally Heming's son Eston using the Y chromosome if we know that President Thomas Jefferson's maternal uncle and Eston Hemings Jeffson have the same Y chromosome? No
Yes

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.

carbon traps heat so more of it makes it hotter causing global warming. during the ice age carbon levels in the atmosphere were low so it got very cold. so the common things between them is carbon levels in the atmosphere.