Re: How does the process of meiosis in sperm compare to pollen production?

Human spermatogenesis and pollen formation (microsporogenesis) both use meiosis
to produce haploid cells. In humans, the haploid cells produced via meiosis
(spermatids) develop into single-celled sperm. 

Unlike animals, plants have an alternation of generations. A diploid sporophyte
alternates with a haploid gametophyte. Sporophytes produce spores. Gametophytes
produce gametes. In seed plants, each haploid cell (microspore) produced by
meiosis divides by mitosis to form a two-celled pollen grain or
microgametotophyte. The generative cell in the pollen grain later divides by
mitosis to produce two sperm. The sperm are protected within the pollen grain
until they are delivered to or near the egg by growth of the pollen tube. 

Depending on the plant species, the sperm may be self-motile with flagella, as
in some gymnosperms such as gingko. In flowering plant species, the sperm are
delivered to the egg sac via the pollen tube. In flowering plants, one of the
sperm fertilizes an egg and the second usually combines with two polar nuclei to
form a triploid primary endosperm nucleus. This process of termed double
fertilization but there are several variations in the second "fertilization".

In flowering plants, pollen is produced in anthers of the flowers. In
gymnosperms, pollen is produced in male cones. Both anthers and cones are
temporary structures. In humans, sperm is produced in a permanent structure, the
seminiferous tubules.

The key difference is that in human spermatogenesis, the sperm are produced
directly via meiosis. In seed plants, two sperm are produced via mitosis in each
multicellular haploid gametophyte or pollen grain. The pollen grain originated
from a haploid cell (the microspore) produced by meiosis.

You can find many more details of spermatogenesis and pollen formation online.

References


Corn life cycle diagram


Plant life cycle diagrams


Microsporogenesis


Human spermatogenesis