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A pistil typically consists of an expanded basal portion called an ovary, an elongated section called a style and an apical structure called a stigma that receives pollen. The ovary (from Latin ovum, meaning egg) is the enlarged basal portion which contains placentas, ridges of tissue bearing one or more ovules (integumented megasporangia). The ...
The part of the ovary where the funiculus attaches is referred to as the placenta. In botany, the term placentation most commonly refers to the arrangement of ovules inside an ovary. Placentation types include: Basal: The placenta is found in mono to multi carpellary, syncarpous ovary. Usually a single ovule is attached at the base (bottom).
There is only one elongated placenta on one side of the ovary, as ovules are attached at the fusion line of the carpel's margins . This is conspicuous in legumes. Simple carpel, unilocular ovary. (e.g. Pisum) Parietal placentation: Placentae on inner ovary wall within a non-sectioned ovary, corresponding to fused carpel margins.
The process begins with fertilization, where an egg released from the ovary of a female is penetrated by a sperm cell from a male. The resulting zygote develops through mitosis and cell differentiation, and the resulting embryo then implants in the uterus, where the embryo continues development through a fetal stage until birth.
The ova, which are the female sex cells, are much larger than the spermatozoon and are normally formed within the ovaries of the female fetus before birth. They are mostly fixed in location within the ovary until their transit to the uterus, and contain nutrients for the later zygote and embryo.
The ovulatory shift hypothesis holds that women experience evolutionarily adaptive changes in subconscious thoughts and behaviors related to mating during different parts of the ovulatory cycle.
Ovulation is an important part of the menstrual cycle in female vertebrates where the egg cells are released from the ovaries as part of the ovarian cycle. In female humans ovulation typically occurs near the midpoint in the menstrual cycle and after the follicular phase. Ovulation is stimulated by an increase in luteinizing hormone (LH).
Prenatal and perinatal psychology can be seen as a part of developmental psychology, although historically it was developed in the heterogenous field of psychoanalysis. Prenatal and perinatal psychology are often discussed together to group the period during pregnancy, childbirth, and through the early stages of infancy.