undertake internal fertilization by transferring a spermatophore, a bundle of sperm, from the male to the female. Following fertilization, the embryos...

surrounding water. Most animals that live outside of water, however, use internal fertilization, transferring sperm directly into the female to prevent the gametes...

Among vertebrates, external fertilization is most common in amphibians and fish. Invertebrates utilizing external fertilization are mostly benthic, sessile...

aspect of mating. Many aquatic animals use external fertilization, whereas internal fertilization may have developed from a need to maintain gametes in...

reproduction and development are varied; all terrestrial species use internal fertilization, but this is sometimes by indirect transfer of the sperm via an...

(gámos) 'marriage') is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive...

Human reproduction is sexual reproduction that results in human fertilization to produce a human offspring. It typically involves sexual intercourse between...

cervix into the uterus or fallopian tubes for fertilization of the ovum. Upon successful fertilization and implantation, gestation of the fetus then occurs...

within the female, which she stores until she is ready for egg fertilization. After fertilization, and the formation of a zygote, and varying degrees of development...

ejaculated to increase the chances of fertilization (see sperm competition), but only one is sufficient to fertilize an egg or ovum. When a fertile ovum...

because an egg is fertilized inside the body, this is in contrast with in vitro fertilisation (IVF). In plants, the fertilization process is referred...

Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes...

animals for insemination and subsequent internal fertilization. Mating may also lead to external fertilization, as seen in amphibians, fishes and plants...

the only other frog genera that have internal fertilization. Limnonectes larvaepartus also has internal fertilization. The family Bufonidae contains over...

the species, spermatozoa can fertilize ova externally or internally. In external fertilization, the spermatozoa fertilize the ova directly, outside of...

(zôion) 'animal') is a motile sperm cell produced by male animals relying on internal fertilization. A spermatozoon is a moving form of the haploid cell that is the...

ejaculation so that sperm can enter the female reproductive tract and fertilize the egg, thus beginning the next stage in human reproduction, pregnancy...

members of Homostiidae, and Heterosteus. Extraordinary evidence of internal fertilization in a placoderm was afforded by the discovery in the Gogo Formation...

makes up about 90% of all species, fertilization is internal. As a general rule, salamanders with internal fertilization have indirect sperm transfer, but...

lordosis reflex is uninhibited. The female is ready for copulation and fertilization. When a male mammal mounts the female, tactile stimuli on the flanks...

fallopian tubes for fertilization of the ovum. Only one sperm is required to fertilize the ovum. Upon successful fertilization, the fertilized ovum, or zygote...

in the epidermis – under control of the prohormone ecdysone, and internal fertilization. The group was initially contested by a significant minority of...

Spermatogenesis Oogenesis Gamete spermatozoon ovum Fertilization External fertilization Internal fertilization Sexual selection Plant reproduction Fungal reproduction...

These are the only North American frog species that reproduce by internal fertilization. They are among the most primitive known families of frogs. Its...

kingdom, the male intromittent organ is a hallmark characteristic of internal fertilization. Male cephalopods have a specialized arm, the hectocotylus, which...

evolves, males and females typically differ in various aspects. Internal fertilization may have originated from oogamy, although some studies suggest : 37 ...

parents: Ovuliparity: Fertilization of eggs is external; zygotes develop externally. Oviparity: Fertilization of eggs is internal; zygotes develop externally...

self-fertilization. Self-fertilization, also known as autogamy, occurs in hermaphroditic organisms where the two gametes fused in fertilization come from...

pellucida, which the sperm must penetrate to fertilize the egg. Once viewed simply as an impediment to fertilization, recent research indicates the zona pellucida...

gland, the ovary and the placenta. The total gestation period from fertilization to birth is normally about 38 weeks (birth usually occurring 40 weeks...