Biology

A. Metamorphosis

In some animal species, the growth of its development and undergo metamorphosis. Events of metamorphosis is a gradual change in body shape starting from larva to adult. Metamorphosis occurs in insects and amphibians.
Examples of amphibians are frogs undergo metamorphosis. Growth and development of the frog starts from the zygote is formed. The zygote then develops into an embryo. One week later, it becomes a larva which often do you call a tadpole / tadpole. At first tadpoles breathe with gills three out, but later changed to the gills.Some time later formed gill cover and the rear legs. After only three months, the tadpoles metamorphosed marked the formation of the lungs and four legs, loss of gills and tail, and a frog shape. Properties different from the properties of frog tadpoles. Tadpoles live in water as herbivores, while land-dwelling frogs are carnivorous.Newly hatched insect larvae tangible. Some insects such as butterflies and dragonflies, larval form is much different from the adult form. Butterfly larvae are called caterpillars have chewing mouth type, while butterflies have sucking mouth type. Dragonfly larvae live in water, while the adult dragonfly can live on land and fly.However, some insects have a similar shape when newly hatched to adulthood. Examples are the grasshoppers, cockroaches, and crickets. Under the process, the metamorphosis of insects can be divided into two, namely metamorphosis and incomplete metamorphosis.

a. Perfect MetamorphosisComplete metamorphosis is characterized by a phase called the pupa or chrysalis. Forms of insect larvae with adults is much different.Stages in the metamorphosis is as follows. eggs? larva pupa (chrysalis) adult (imago) The eggs hatch into larvae. Larvae do not have wings and wing signs as well not exist. When a larva, insects are very active feeding. Larvae then pupate changing shape. Larvae to pupa there is a direct, but there is also a patron of the first to make a folded leaf, soil or fine sand, fine wood cuts, and other materials.Shelters around the pupa called a chrysalis or cocoon. In the pupa stage, the insect is actively feeding, although the metabolic process is ongoing. After passing through the pupa stage, the insect would be the adult (imago).

b. Incomplete metamorphosis (Hemimetabola)Insects that have incomplete metamorphosis, the newly hatched form of insects (nymphs) are not much different from the adult form of the insect (imago). A striking difference is the nymph has no wings. The wings will grow in stages so as to resemble the adult form. In general, nymphs and adult insects have the same properties. For example in crickets and grasshoppers. The order of the life cycle of insects that have incomplete metamorphosis is as follows. eggs (nymphs) adult (imago).

2. MetagenesisSome types of plants and animals there are experiencing metagenesis process. Metagenesis rotation is the process of life, namely between sexual and asexual phases. Animals and plants that have metagenesis will have two phases of life, that phase of life that reproduce sexually, and the pace of life that reproduce asexually.Metagenesis in plants can be observed clearly in seedless plants (spikes and moss). In plants, the male gamete formation takes place in the antheridium and female gametes in arkegonium. If the male gametes to fertilize female gametes, it will form a zygote.Zygotes grow into individuals that produce spores. This generation is called the phase of vegetative (asexual) or sporophytes. Spores that fall in the corresponding place will grow into new individuals that produce gametes. Because it produces gametes, the generation phase is called generative (sexual) or gametophyte. So forth offspring rotation occurs between the phases gametophyte and sporophytes. Mosses that often you find a gametophyte phase. While ferns that you see everyday is the phase of sporophytes.Descendants of the phase rotation between sporophytes and gametophyte is called metagenesis.Some of the lower animals also experienced metagenesis, for example, Obelia and Aurelia. Note metagenesis jellyfish (Aurelia).Jellyfish (Aurelia) have two kinds of life that is life when attached (polyp) and life moves freely (medusa).