Answer:
Many rare and/or endemic species exhibit one or more of the following attributes which make them especially prone to extinction: (1) narrow (and single) geographical range, (2) only one or a few populations, (3) small population size and little genetic variability, (4) over-exploitation by people
This change in chromosome number is the result of B. Fertilization. Both of the individual gametes from the male and female combine together to produce a zygote or developing offspring that is diploid in most cases, and possess both sets of genetic content or chromosomal information, one from each parent.