Two types of genes play major roles in regulating the cell cycle: proto-oncogenes encourage cell division, while tumor-suppressor genes inhibit cell division. the balance between these two types of genes may be disrupted by naturally occurring or environmentally caused

The right answer is b hydrogen bonds!

The soviet union beat the us to the first successful launch, with the october 4, 1957, orbiting of sputnik 1, and later beat the us to have the first human in earth orbit, yuri gagarin, on april 12, 1961. the "race" peaked with the july 20, 1969, us landing of the first humans on the moon with apollo 11

Carbon-14 has a half-life of 5,730 years and most igneous rock is older than that.