what is sex without sex no baby will form why boys and girls do sex for what purpose explain briefly in science

Look at the following answer choices and determine which belongs in the both category. testable, can be disproven explains natural phenomena, has evidence to support it prediction, tentative, one or more scientists working together well established, many different scientists working independently, highly reliable

The first generation of offspring from the cross of two parents is called the a.f1 generation b.f2 generation c.short generation d.p generation

Crossing over is a method of (blank)?