Zoology

Sea fur is an alternative term for Obelia. Obelia has a delicate, semitransparent, pale to light-brown hydroid colony. It consists of stems with vertical branches called hydrocauli and root-like branches called hydrorhiza. In order to complete its life cycle, Obelia’s asexual and sexual generations alternate. The life cycle of Obelia regularly alternates between hydroid and … Read more

What is Protista? – Protista Definition Different Locomotion organs of Protista Protists are a heterogeneous group of unicellular eukaryotic creatures with a vast array of movement techniques. Certain protists utilise flagella, cilia, or pseudopodia for locomotion. 1. Flagella Some protists have long, whip-like appendages called flagella that protrude from their surface. They are utilised for … Read more

What is Polymorphism in cnidarians? The majority of polyps are sessile, whereas meduase types are motile. Nonetheless, there is a similarity between the two in their fundamental characteristics. Importance of Polymorphism Polymorphism is fundamentally a phenomena of labour division. Rather than assigning diverse functions to the components or organs of a single individual, distinct functions … Read more

Protists are a varied category of eukaryotic creatures that are unicellular or multicellular, and can be free-living or parasitic. They have a simple cellular structure, with a nucleus and other membrane-bound organelles, and are capable of a wide variety of metabolic operations, including as photosynthesis, digesting, and locomotion. Protists are found in nearly all habitats … Read more

The water circulation system of sponges, also known as canal system, is the defining property of the phylum Porifera. The system of canals is also known as the auriferous system. The sponge canal system aids in food uptake, respiratory gas exchange, and excretion. Many pores on the body surface of sponges allow for the admission … Read more

What is Phylum Platyhelminthes? Definition of Phylum Platyhelminthes Phylum Platyhelminthes, also known as flatworms, comprises bilaterally symmetrical, triploblastic, dorsoventrally flattened invertebrates lacking circulatory, respiratory, and skeletal systems, characterized by a simple digestive system with a single opening and a protonephridial excretory system. Characteristics of Phylum Platyhelminthes Classification of Phylum Platyhelminthes Class 1- Turbellaria (L., turbella= a little … Read more

What is Phylum Porifera? – Definition of Phylum Porifera Phylum Porifera refers to a group of simple, sessile aquatic animals commonly known as sponges. Sponges lack true tissues and organs and have a porous body structure with numerous channels and chambers that allow water to flow through them. They feed by filtering small particles from … Read more

Origin of Parazoa Choanoflagellate: Link to sponges Sponges’ internal chambers are bordered by a series of specialised cells known as choanocytes (choano = collar; cyte =cell). These are the cells that feed sponges. Each choanocyte, like choanoflagellates, possesses a collar of tentacles enclosing a single anterior flagellum. By undulating dozens of flagella, choanocytes generate a … Read more

Reproduction in Protista Methods of Reproduction in Protists The following paragraphs emphasise the two essential reproductive strategies of protists. The procedures are: A. Asexual Reproduction in Protists Mode of Asexual Reproduction In Protista 1. Binary Fission Mitosis is the division of the parent cell into two identical daughter cells. Examples: Amoeba, Euglena and Paramecium. 2. … Read more