The answer is ‘the only truly distinctive primate trait’. Prehensile hands are a distinctive trait of primates an opposable thumb (capable of grasping). The digits have nails instead of claws, and tactile pads enriched with sensory nerve fibers at the ends of digits to feel to manipulate objects.
Ribosomal ribonucleic acid
The correct answer here is "cell membrane". Generally it makes sure that nothing enters or leaves the cell, except by its highly guarded "gates", such as ion channels, that let some particles through - but they're very picky about whom to let in!
Meiosis is important because it ensures that all organisms produced via sexual reproduction contain the correct number of chromosomes.
