What is parthenogenesis? give an example

It's a form of asexual reproduction!

Development of the offspring happens without fertilization in this type of reproduction.

The two main ways in which parthenogenesis happens is by apomixis or automixis. Through apomixis , the egg cells are produced by mitosis. Through In automixis, egg cells are produced by meiosis.

Mitosis = a part of cell cycle: replicated chromosomes are separated into 2 nuclei

Meiosis = type of cell division that reduces the chromosome number by half. So now there is four haploid cells that are  genetically distinct from their parent cell.

Example:

An example of an animal that can use this reproduction is a bonnethead shark! Once a shark had a baby in a tank that only had three females!

(read about that on wikipedia)