C. Desert
A. The tilt of the Earth's axis as it circles the Sun.
Answer: Spermatogenesis begins at birth and continues throughout a man's life.
The process in which
haploid spermatozoa develop from germ cells in the seminiferous tubules of the
testis is known as Spermatogenesis. Thus, the process of spermatogenesis start
with mitotic division of the stem cells that is located close to the basement
membrane of the tubules. However, a mature male gametes known as sperm but it
is commonly known as spermatozoa.
A. Abrasion
Reason - cause by scraps on rough surface which breaks skin on outer layer.
Heart,vessels,circulating fluids
