Phylum Mollusca- characteristics, classification, examples

Phylum Mollusca

Mollusca (Mollusks) Definition Molluscs (also know as mollusks) are soft-bodied, bilaterally symmetrical, segmented, coelomate animals; usually shelled having a mantle, ventral foot, anterior head, and a dorsal visceral mass. Phylum Mollusca (Mollusks) Characteristics They are essentially aquatic mostly marine, few freshwater and some terrestrial form. They may be found as hidden parasites in the interior … Read more Phylum Mollusca- characteristics, classification, examples

Phylum Nematoda- characteristics, classification, examples

Phylum Nematoda

Nematoda Definition Nematodes (Gr., nema thread+ eidos, form) are commonly referred to as non-segmented roundworm, threadworm or pinworm, as distinct from flatworm and higher segmented annelids. Image Source: Wikipedia Phylum Nematoda Characteristics They are widely distributed, aquatic or terrestrial, parasitic or free-living. Their body is elongated, cylindrical, unsegmented, worm-like, bilaterally symmetrical and tapering at both … Read more Phylum Nematoda- characteristics, classification, examples

Phylum Aschelminthes- characteristics, classification, examples

Phylum Aschelminthes

What are Aschelminthes? Aschelminthes are pseudocoelomate, bilaterally symmetrical, triploblastic, unsegmented, vermiform, organ- system grade of construction with complete digestive tubes. Phylum Aschelminthes characteristics They are mostly aquatic, free-living or parasitic. They are bilaterally symmetrical, unsegmented worms. The body is slender, vermiform and usually worm-like or flattened. They are usually small, even microscopic, while some reach … Read more Phylum Aschelminthes- characteristics, classification, examples

Phylum Platyhelminthes- characteristics, classification, examples

Phylum Platyhelminthes (flatworms)

Platyhelminthes (flatworms) definition Platyhelminthes are triploblastic, bilaterally symmetrical, dorsoventrally flattened, acoelomate flatworms with organ grade of construction without a definite anus, circulatory, skeletal or respiratory system but with Protonephridial excretory system and mesenchyme filling the space between the various organ of the body. Figure: Phylum Platyhelminthes. Source: WebMD and Wikipedia. Phylum Platyhelminthes (flatworms) characteristics They … Read more Phylum Platyhelminthes- characteristics, classification, examples

Phylum Annelida- characteristics, classification, examples

Diagram of Phylum Annelida

Annelida definition Annelids are defined as triploblastic, bilaterally symmetrical, metamerically segmented, a coelomate worm with a thin flexible cuticle around the body. Figure: Diagram of Phylum Annelida. Source: Wikipedia Phylum Annelida Characteristics They are mostly aquatic; marine or freshwater some terrestrial, burrowing or tubicolous, sedentary or free-living, some commensal and parasitic. The body is elongated, … Read more Phylum Annelida- characteristics, classification, examples

Types of Plant Cell – Definition, Structure, Functions, Diagrams

Types of Plant Cell

Definition and overview of a plant cell Plant cells are multicellular eukaryotic cells that make up a plant (a group of eukaryotes belonging to the Plantae kingdom, with the ability to synthesis their own food using water, Sunlight and CO2). Being eukaryotic cells, they have a defined nucleus with specialized structural organelles that enable it … Read more Types of Plant Cell – Definition, Structure, Functions, Diagrams

Developmental Biology

Developmental Biology

What is Developmental Biology? It is the field of biology that studies the processes by which multicellular organisms grow and develop, controlled by their genes.  It involves the study of mechanisms of development, differentiation, and growth in animals and plants at the molecular, cellular, genetic and evolutionary levels. It also encompasses the biology of regeneration, asexual reproduction, metamorphosis, and the growth and differentiation … Read more Developmental Biology

General Characteristics of Phylum Porifera

General Characteristics of Phylum Porifera

General Characteristics of Phylum Porifera Some of the characteristics are: Porifera are all aquatic, mostly marine except one family Spongillidae which lives in freshwater. They are sessile and sedentary and grow like plants. The body shape is vase or cylinder-like, asymmetrical or radially symmetrical. The body surface is perforated by numerous pores, the Ostia through … Read more General Characteristics of Phylum Porifera

Protozoa- Definition, characteristics, classification, examples

General Characters of Phylum Protozoa

Protozoa Definition Protozoa may be defined as  “microscopic acellular animalcules existing singly or in colonies, without tissue and organs, having one or more nuclei”. Some of the characteristics are: There are about 50,000 known species of Phylum Protozoa. Protozoans exhibit mainly two forms of life; free-living (aquatic, freshwater, seawater) and parasitic (ectoparasites or endoparasites). They … Read more Protozoa- Definition, characteristics, classification, examples

Classification of Phylum Protozoa

Classification of Phylum Protozoa

Classification of Phylum Protozoa Phylum protozoa is a large and varied group and possess a complication in its classification. The conventional scheme followed by Hyman (1940), Hickman (1961) and Storer (1965) etc. recognizes two subphyla on the basis of organs of locomotion and 5 classes as follows: Sub Phylum A: Plasmodroma Locomotory organelles are flagella, … Read more Classification of Phylum Protozoa

Lower and Higher Invertebrates with their differences

Lower and Higher Invertebrates

Lower and Higher Invertebrates with their differences The invertebrates are usually classified as Lower Invertebrates and Higher Invertebrates. Lower Invertebrates The lower invertebrates are simple in body organization. They are generally small in size. These are thought to have originated in the main lines of evolution, near the base of the phylogenetic tree of Animal … Read more Lower and Higher Invertebrates with their differences

Characteristics of Invertebrates with examples

Characteristics of Invertebrates

Habitat They are found in seas, freshwater, air, land from snow to desert. 80% are found in terrestrial habitat. Most successful invertebrates of the lands are Arthropods. Protozoans are free-living, parasites or commensals. Sponges and Coelenterates are aquatic animals. Numerical Strength Among 1.25 million animal species, 95% (1.2 million) are invertebrates. Among 1.2 million invertebrates, … Read more Characteristics of Invertebrates with examples

Differences between Invertebrates and Vertebrates

Differences between Invertebrates and Vertebrates

Differences between Invertebrates and Vertebrates The animal kingdom has been divided into two major groups: Invertebrates (Non-Chordates) and Vertebrates (Chordates). Invertebrates are those that do not possess a vertebral column or backbone while Vertebrates are those where vertebral column or backbone is present. These two groups have some differences as follows: S.N. Characteristics Invertebrates (Non-Chordates) … Read more Differences between Invertebrates and Vertebrates