Zoology - Biology Notes Online

Sense Organs – Classification of receptors, Brief account of visual and auditory receptors in man

By Sourav Pan Published on October 4, 2024 34 min readby Sourav Pan

Comparative Anatomy of the Vertebrate Eye

What are Sense Organs? Types of Sensory Receptors Sensory receptors in vertebrates are specialized structures that detect various types of stimuli from both the external and internal environments. These receptors convert sensory input into electrical signals, which are then transmitted to the brain for processing. Sensory receptors are classified based on their distribution, location, and … Read more

Urogenital System in Vertebrates – Structure, Development, Succession, Evolution, Significance

By Sourav Pan Published on October 4, 2024 22 min readby Sourav Pan

Urogenital System in Vertebrates - Structure, Development, Succession, Evolution, Significance

What is Urogenital System? Male and Female Excretory System The male and female excretory systems share significant similarities in structure, particularly concerning the kidneys, ureters, bladder, and urethra. Despite these commonalities, there are notable differences, particularly in the anatomy and function of the urethra. Development of Urogenital System The development of the urogenital system is … Read more

Comparative Anatomy and associated glands of Digestive Systems In Vertebrates

By Sourav Pan Published on October 4, 2024 31 min readby Sourav Pan

Comparative Anatomy and associated glands of Digestive Systems In Vertebrates

The digestive tract of vertebrates The digestive tract of vertebrates consists of several distinct parts, each playing a crucial role in the overall process of digestion. From the mouth to the glands associated with digestion, this system is designed to break down food, absorb nutrients, and expel waste. Below is a detailed breakdown of the … Read more

Skeletal System In Vertebrates – Axial and Appendicular Skeleton

By Sourav Pan Published on October 3, 2024 48 min readby Sourav Pan

Cartilage and Bone: Key Components of the Vertebrate Skeletal System The vertebrate skeletal system is primarily composed of two types of connective tissue: cartilage and bone. Both play crucial roles in providing structural support, protection, and aiding in locomotion. Although both tissues are essential for the overall functioning of the skeleton, they differ significantly in … Read more

Parental Care in Amphibia – Protection by Nests and Direct Carrying by Parents

By Sourav Pan Published on October 3, 2024 11 min readby Sourav Pan

Parental Care in Amphibia - Protection by Nests and Direct Carrying by Parents

Parental Care in Amphibia 1. Protection by Nests, Nurseries, or Shelters in Amphibians Amphibians have evolved a variety of innovative strategies to protect their vulnerable eggs and larvae from predation. These methods often involve creating safe microhabitats that shield offspring until they are capable of defending themselves. The protection by nests, nurseries, or shelters can … Read more

Origin of Tetrapods (Amphibia)

By Sourav Pan Published on October 3, 2024 14 min readby Sourav Pan

Tetrapod phylogeny from The Tangled Bank, used with permission of the author, Carl Zimmer, and publisher, Roberts & Company, Greenwood Village, Colorado.

Tetrapoda: Evolution from Fish to Land-Dwelling Vertebrates Tetrapods are a group of vertebrates that includes amphibians, reptiles, birds, and mammals. The first tetrapods evolved during the Devonian period from crossopterygian fishes, which were adapted to shallow, marshy environments. These fishes already possessed some features that made their transition to land possible. The transition from aquatic … Read more

Amphibian – Characteristics, Origin, Morphology, Classification

By Sourav Pan Published on October 3, 2024 25 min readby Sourav Pan

Amphibian - Characteristics, Origin, Morphology, Classification

What is Amphibian? Scientific Classification of Amphibian Category Classification Kingdom Animalia Phylum Chordata Clade Batrachomorpha Class Amphibia Order Anura, Caudata, Gymnophiona Amphibians are believed to have evolved from a population of osteolepid fishes during the later part of the Devonian period. These fishes began spending more time on land, moving from one pool to another. … Read more

Sphenodon – Morphology, Habitat, Affinities

By Sourav Pan Published on October 3, 2024 26 min readby Sourav Pan

Sphenodon - Morphology, Habitat, Affinities

What is Sphenodon? Habits and Habitat of Sphenodon Sphenodon, commonly known as the tuatara, exhibits a range of distinct behaviors and occupies specific habitats that have enabled it to survive as a relic of ancient reptilian lineages. These habits and habitat preferences are vital to understanding the unique biology and conservation needs of this species. … Read more

Protochordata – Characteristics and Classification

By Sourav Pan Published on October 3, 2024 24 min readby Sourav Pan

Protochordata - Characteristics and Classification

What is Protochordata? Characteristics of Protochordata Protochordata, often referred to as primitive chordates, exhibit several defining features that differentiate them from more advanced vertebrates. These organisms are primarily marine and show a blend of both invertebrate and vertebrate characteristics. Below is a detailed overview of the key characteristics of protochordates: Classification of Protochordata Protochordate is … Read more

Phylum Chordata – Characteristics and Classification

By Sourav Pan Published on October 2, 2024 26 min readby Sourav Pan

Phylum Chordata - Characteristics and Classification

What is Chordata? Characteristics of Chordates Below are the main characteristics of chordates: In addition to the primary characteristics listed above, chordates share several other notable features: Anatomy of Chordates The anatomy of chordates encompasses a unique set of features that distinguishes them from other animal phyla. These anatomical characteristics manifest at various life stages … Read more