Which of the following are the smallest cells?
a) human ovum
b) red blood cells
c) white blood cells
d) smooth muscle cell

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

Centriole.centrioles are present in animal cells but are usually absent in plant cells.