How does kingdom animalia reproduce

Sponges : Sponges, such as those in the Caribbean Sea, are classified as Parazoans because they are very simple animals that do not contain true specialized tissues. The different types of tissues in true animals are responsible for carrying out specific functions for the organism. This differentiation and specialization of tissues is part of what allows for such incredible animal diversity.

This allows animals to survive in environments where they must compete with other species to meet their nutritional demands. Most animals undergo sexual reproduction and have similar forms of development dictated by Hox genes. Most animals are diploid organisms their body, or somatic, cells are diploid with haploid reproductive gamete cells produced through meiosis. The majority of animals undergo sexual reproduction.

This fact distinguishes animals from fungi, protists, and bacteria where asexual reproduction is common or exclusive. However, a few groups, such as cnidarians, flatworms, and roundworms, undergo asexual reproduction, although nearly all of those animals also have a sexual phase to their life cycle.

During sexual reproduction, the haploid gametes of the male and female individuals of a species combine in a process called fertilization. Typically, the small, motile male sperm fertilizes the much larger, sessile female egg.

This process produces a diploid fertilized egg called a zygote. Some animal species including sea stars and sea anemones, as well as some insects, reptiles, and fish are capable of asexual reproduction. The most common forms of asexual reproduction for stationary aquatic animals include budding and fragmentation where part of a parent individual can separate and grow into a new individual.

In contrast, a form of asexual reproduction found in certain insects and vertebrates is called parthenogenesis where unfertilized eggs can develop into new offspring. This type of parthenogenesis in insects is called haplodiploidy and results in male offspring. These types of asexual reproduction produce genetically identical offspring, which is disadvantageous from the perspective of evolutionary adaptability because of the potential buildup of deleterious mutations. However, for animals that are limited in their capacity to attract mates, asexual reproduction can ensure genetic propagation.

After fertilization, a series of developmental stages occur during which primary germ layers are established and reorganize to form an embryo. During this process, animal tissues begin to specialize and organize into organs and organ systems, determining their future morphology and physiology. Some animals, such as grasshoppers, undergo incomplete metamorphosis, in which the young resemble the adult.

Other animals, such as some insects, undergo complete metamorphosis where individuals enter one or more larval stages that may differ in structure and function from the adult. In complete metamorphosis, the young and the adult may have different diets, limiting competition for food between them. Regardless of whether a species undergoes complete or incomplete metamorphosis, the series of developmental stages of the embryo remains largely the same for most members of the animal kingdom.

Incomplete and complete metamorphosis : a The grasshopper undergoes incomplete metamorphosis. The process of animal development begins with the cleavage, or series of mitotic cell divisions, of the zygote.

Three cell divisions transform the single-celled zygote into an eight-celled structure. After further cell division and rearrangement of existing cells, a 6—celled hollow structure called a blastula is formed. Next, the blastula undergoes further cell division and cellular rearrangement during a process called gastrulation.

This leads to the formation of the next developmental stage, the gastrula, in which the future digestive cavity is formed. Different cell layers called germ layers are formed during gastrulation. These germ layers are programed to develop into certain tissue types, organs, and organ systems during a process called organogenesis.

Embryonic development : During embryonic development, the zygote undergoes a series of mitotic cell divisions, or cleavages, to form an eight-cell stage, then a hollow blastula. During a process called gastrulation, the blastula folds inward to form a cavity in the gastrula. Since the early 19 th century, scientists have observed that many animals, from the very simple to the complex, shared similar embryonic morphology and development.

Surprisingly, a human embryo and a frog embryo, at a certain stage of embryonic development, appear remarkably similar.

For a long time, scientists did not understand why so many animal species looked similar during embryonic development, but were very different as adults. Near the end of the 20 th century, a particular class of genes that dictate developmental direction was discovered.

Most reproduce sexually, by means of differentiated eggs and sperm. Most animals are diploid, meaning that the cells of adults contain two copies of the genetic material. The development of most animals is characterized by distinctive stages, including a zygote, formed by the product of the first few division of cells following fertilization; a blastula, which is a hollow ball of cells formed by the developing zygote; and a gastrula, which is formed when the blastula folds in on itself to form a double-walled structure with an opening to the outside, the blastopore.

It is estimated that around 9 or 10 million species of animals inhabit the earth; the exact number is not known and all estimates are rough. Animals range in size from no more than a few cells to organisms weighing many tons, such as blue whales and giant squid.

By far most species of animals are insects , with groups such as mollusks , crustaceans , and nematodes also being especially diverse. By this measure our own group, the vertebrates , is relatively inconsequential from a diversity perspective. Research continues on the evolutionary relationships of the major groups of animals. For the sake of convenience, the Animal Diversity Web follows the system outlined in Hickman and Roberts For some groups we incorporate the results of current research in our classification and discussion.

To cite this page: Myers, P. Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts.

While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control. Animalia animals Facebook. Read more Classification Kingdom Animalia animals Animalia: information 1 Animalia: pictures Animalia: specimens Animalia: sounds Animalia: maps Division Anthophyta flowering plants. Biological Organization. Species a distinct kind or unit. Twenty of the more than species of Pinus on earth.

All of these pines are native to the state of California, USA. Monterey Pine P. Bishop Pine P. Santa Cruz Island Pine P. Whitebark Pine P. Limber Pine P. Beach Pine P. Lodgepole Pine P. Western White Pine P. Knobcone Pine P. Bristlecone Pine P.

Foxtail Pine P. Four-Leaf Pinyon P. Two-Leaf Pinyon P. One-Leaf Pinyon P. Ponderosa Pine P. Coulter Pine P. Digger Pine P. Torrey Pine P.

Jeffrey Pine P. Sugar Pine P. Another species left image called the Washoe Pine P. In addition, the Beach and Lodgepole Pines are now recognized as subspecies of P. According to R. Lanner Conifers of California , , there may be other significant changes in the pines of California.

Allozyme studies in two-leaf pinyons Pinus edulis of the New York Mountains indicate that these populations are biochemically and genetically consistent with nearby one-leaf pinyon Pinus monophylla , and that P.

The unusual New York Mountains population appears to be a 2-needle variant of P. According to Lanner, the latter species has five needles per fascicle and occurs in San Diego County. The hybrid hypothesis might explain the perplexing variation in needle number for P. Foxtail pines Pinus balfouriana on the 11, ft m slopes of Alta Peak. The 13, ft. Left: Seed cones of cypress Cupressus from groves in southern California. Tecate cypress C. Sargent cypress C. Piute cypress C.

Cuyamaca cypress C. Smooth-bark Arizona cypress C. Rough-bark Arizona cypress C. Right: Seed cones of cypress from groves in central and northern California. Monterey cypress C. Gowen cypress C. Santa Cruz cypress C. Mendocino cypress C.

Macnab cypress C. Modoc cypress C.