Kaksikotinen

Kaksikotinen refers to a biological characteristic where a species has separate male and female individuals. This condition, known as dioecy, is common in many plant and animal groups. In plants, this means that a single plant is either male, producing only pollen, or female, producing only ovules. For successful reproduction, pollen must be transferred from a male plant to a female plant, often facilitated by wind or animal pollinators. This contrasts with monoecious species, where an individual organism possesses both male and female reproductive organs.

Examples of kaksikotinen plants include willows, sea buckthorn, and spinach. In animals, it describes species where distinct male and female sexes exist. For instance, humans, most mammals, and many bird species are kaksikotinen. This sexual dimorphism often leads to differences in appearance, behavior, and size between males and females. The genetic determination of sex in kaksikotinen organisms varies widely, involving chromosomal mechanisms, environmental factors, or a combination of both. The presence of separate sexes is a fundamental aspect of sexual reproduction, contributing to genetic diversity within populations.