The fertilization process is the process where specialized sex cells, known as male and female gametes, combine to form a new cell, known as a zygote. The fertilized cell then develops into a new offspring with its own set of genetic material. The offspring’s genetic material combines genes from the two donors, and this leads to genetic variation, an important aspect of survival in a population.Know More
Fertilization can occur through two mechanisms. The first one is external where eggs are fertilized outside the body, and the second mechanism is internal, with the eggs fertilized inside of the organism’s body. External fertilization mostly occurs in wet environments and requires the two organisms to discharge their gametes into their immediate environs. In internal fertilizations, the organisms have specialized body parts to safeguard the developing egg.
Although fertilization is necessary for organisms that reproduce sexually, some organisms do not need fertilization to reproduce. This is called asexual reproduction. In asexual reproduction, an organism reproduces by creating a clone of itself through mitosis, a cell division process, without the need for fertilization.
In bisexual organisms, sexual reproduction occurs when male and female gametes from a single organism fuse. This is known as self-fertilization and is common in many flowering plants, invertebrates and protozoans.Learn more about Animal Reproduction
Bettas, also known as Siamese fighting fish, reproduce via external fertilization, which means that the female releases eggs and the male releases milt. The male is responsible for creating a "bubble nest," which is where the eggs are kept until they hatch.Full Answer >
Platyhelminthes, also known as flatworms, are hermaphrodites, meaning individuals of the species produce both sperm and eggs. These are released from the platyhelminthes where they become cross-fertilized by other platyhelminthes. Two types of platyhelminthes, trematoda and cestoda, lay eggs constantly. The turbellarian class has a seasonal cycle. Turbellaria also reproduce asexually by dividing. Turbellaria are the only class able to regenerate body parts.Full Answer >
According to PetMD, phantom pregnancy in dogs, also known as false pregnancy or pseudopregnancy, is most likely caused by hormonal imbalances, especially of progesterone and prolactin. The female dog starts showing pregnancy symptoms or begins lactating within a month or two after her latest heat cycle (estrus) concludes.Full Answer >
Tetrads, also known as bivalents, form during the prophase 1 stage of meiosis when duplicated chromosomes, each composed of two identical chromatids, pair up and complete the process of crossing over in which one chromosome exchanges corresponding segments of genetic material with the other chromosome in the tetrad. This exchange of physical parts and genetic information creates a tight grouping of the two chromosomes, each consisting of two sister chromatids.Full Answer >