性別（sex），为一种繁殖系统特性，划分不同个体的分类方式. 生物中有許多物種可以劃分成雄性和雌性. 有性生殖是雄性和雌性生物的基因特性混合重組
Claws are curved, pointed appendages found at the ends of toes and fingers. True claws are made of keratin and consist of two layers. Flat, non-pointing structures are called nails
Generalization abstracts common properties from specific instances. A generalization requires both instances of B being instances of A and A not being B. Parts cannot be generalized until common relation is established
Fission is the division of a single entity into two or more parts. Binary fission produces two genetically identical daughter cells. Multiple fission creates multiple daughter cells from a single entity
Pseudopodia are temporary arm-like projections of eukaryotic cell membranes. Contain actin filaments, microtubules, and sometimes intermediate filaments. Used for motility and ingestion, especially in amoebas
Hypha is a long, branching filamentous structure of fungi. Consists of cells surrounded by tubular cell wall. Divided into cells by internal cross-walls called septa. Average diameter of 4-6 μm