male sperm cell
51spermatozoa — (sperm) A male reproductive cell. The male fertilizing element of an animal, usually in the form of a nucleated cell with a long flagellate process or tail by which it swims actively about …
52spermatozoon — sperm; n.; pl. spermatozoa a mature male sex cell (see gamete). The tail of a sperm enables it to swim, which is important as a means for reaching and fertilizing the ovum (although muscular movements of the uterus may assist its journey from the …
53sex — /seks/, n. 1. either the male or female division of a species, esp. as differentiated with reference to the reproductive functions. 2. the sum of the structural and functional differences by which the male and female are distinguished, or the… …
54reproductive system, animal — Introduction any of the organ systems by which animals reproduce. The role of reproduction is to provide for the continued existence of a species; it is the process by which living organisms duplicate themselves. Animals compete with… …
55animal development — Introduction the processes that lead eventually to the formation of a new animal starting from cells derived from one or more parent individuals. Development thus occurs following the process by which a new generation of organisms is produced by …
56Sex — An organism s sex is defined by the gametes it produces: males produce male gametes (spermatozoa, or sperm) while females produce female gametes (ova, or egg cells); individual organisms which produce both male and female gametes are termed… …
57Drosophila melanogaster — Male Drosophila melanogaster Scientific classification Kingdom …
58Fertilisation — This article is about fertilisation in animals and plants. For fertilisation in humans specifically, see Human fertilization. For Soil improvement, see Fertiliser. Conceive redirects here. For the health magazine, see Conceive magazine. For… …
59Parthenogenesis — (from the Greek παρθένος parthenos , virgin , + γένεσις genesis , creation ) is an asexual form of reproduction found in females where growth and development of embryos or seeds occurs without fertilization by a male. The offspring produced by… …
60human embryology — ▪ biology Introduction the process encompassing the period from the formation of an embryo, through the development of a fetus, to birth. The human body, like that of most animals, develops from a single cell produced by the union of… …
