Reproduction mechanism in paramecium , reproductive mechanism in obelia, sexual reproduction in cockroach, metamorphosis in Insects, general accounts and affinities of ctenophora and rotifera?

Reproduction mechanism in Paramecium:
Paramecium reproduces asexually through a process called binary fission. During binary fission, the Paramecium cell divides into two daughter cells, each with a complete set of genetic material. This process occurs when the Paramecium reaches a certain size and undergoes a series of cellular divisions.

Reproductive mechanism in Obelia:
Obelia is a colonial hydrozoan that reproduces both sexually and asexually. Asexual reproduction occurs through budding, where new individuals called polyps develop as outgrowths from the parent colony. These polyps can then detach and form new colonies. Sexual reproduction occurs through the production of medusae, which are free-swimming jellyfish-like individuals. The medusae release eggs and sperm into the water, where fertilization takes place, leading to the development of new colonies.

Sexual reproduction in Cockroach:
Cockroaches reproduce sexually. The male cockroach transfers sperm to the female through a specialized structure called the spermatophore. The female then stores the sperm in a structure called the spermatheca. When the female is ready to lay eggs, she fertilizes them with the stored sperm. The fertilized eggs are then deposited in a protective case called an ootheca, which is attached to a suitable surface. The eggs hatch into nymphs, which undergo several molts before reaching adulthood.

Metamorphosis in Insects:
Metamorphosis is a process of transformation that insects undergo during their development. It involves distinct stages: egg, larva, pupa, and adult. Insects that undergo complete metamorphosis, such as butterflies and beetles, have a larval stage where they look completely different from the adult form. The larva feeds and grows until it enters the pupal stage, during which it undergoes a complete restructuring of its body. Finally, the adult insect emerges from the pupa with fully developed wings and reproductive organs.

General accounts and affinities of Ctenophora and Rotifera:
Ctenophora, commonly known as comb jellies, are marine invertebrates characterized by their comb-like rows of cilia used for locomotion. They have a gelatinous body and are radially symmetrical. Ctenophora are considered to be the most primitive group of animals with true tissues.

Rotifera, also known as rotifers, are microscopic aquatic animals. They have a wheel-like structure called a corona, which is covered in cilia and used for feeding and locomotion. Rotifers are bilaterally symmetrical and possess a complete digestive system. They are known for their ability to survive in a wide range of habitats, including freshwater, marine, and terrestrial environments.

Both Ctenophora and Rotifera are considered to be basal or early-branching animal groups. They share some similarities in their body structures and reproductive mechanisms. However, their exact evolutionary relationships and affinities with other animal groups are still a subject of scientific debate and research.