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How does parthenogenesis allow an egg to develop without fertilization?

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A series of medical illustrations showing the stages of childbirth: the baby's position at the onset of labor, flexion, internal rotation of the head, extension, external rotation of the head, and the uterus immediately after birth with the placenta and umbilical cord. — birth Sequential changes in the position of the child during labour.

Parthenogenesis is a reproductive strategy where an egg develops into an organism without being fertilized by sperm. While often described as asexual, it is more accurately an incomplete form of sexual reproduction because it involves gametes, which are cells typically produced through meiosis.1

The mechanisms for this development vary depending on the species:

Haploid Parthenogenesis: In some species, such as certain bees and plants, offspring develop directly from haploid eggs to become haploid adults.1
Diploid Parthenogenesis (Automixis): A haploid cell may duplicate its chromosomes or join with another haploid cell to form a diploid zygote, which then develops into a diploid adult.1
Diploid Parthenogenesis (Apomixis): The organism bypasses meiosis entirely. Instead, diploid egg cells are produced through mitosis, resulting in offspring that are genetically identical clones of the parent.1
Pseudogamy: In some species, sperm is required to stimulate the egg's development, but the sperm's genetic material is not incorporated into the offspring.1

These processes allow for reproduction in the absence of fertilization, ensuring the continuation of the species in various environmental conditions.1