Online Biology Notes for students
The excretory organs are segmentally arranged, microscopic, coiled tubules called nephridia. Nephridia are ectodermal in origin. These are typically unbranched, and their inner ends open into coelom by a ciliated funnel, called nephrostome. A large number of small-sized nephridia are found in each segment which are called micronephridia and mesonephridia. Nephridia occur …
Circulatory system of earthworm The circulatory or blood vascular system of an earthworm is a closed type. It consists of the blood vessel, heart, capillaries, and blood glands. Blood is composed of fluid plasma and colorless corpuscles. Blood is red in color due to the presence of respiratory pigment hemoglobin (erythrocruorin) in …
Habit and Habitat of Earthworm The Earthworms are burrowers. It prefers to live in the burrow during the day and comes out at night and in damp cloudy weather for the search of food, reproduction, and exploring fresh habit. Thus, nocturnal in habit. The rainy season is the most favorable time for …
Read moreEarthworm- Habit, Habitat, Morphology, Bodywall, Locomotion
Well developed and concentrated nervous system. Consists of 3 parts: the central, peripheral, and sympathetic nervous system. Figure: Nervous System of Earthworm. Image Source: Meridian Technical Charter High School. 1. Central nervous system It comprises of the anterior nerve ring or brain ring and the posterior ventral nerve cord. Nerve ring Comprises …
Earthworms are simple, commonplace creatures, are of greater economic value to human beings in different ways. Our earth would be an afar different place without them. They have both useful and harmful aspects of mankind. Useful effects of Earthworm In Agriculture They are beneficial but sometimes they may damage the young and …
Earthworms have well-developed sense organs or receptor organs. Simple in structures. Reacts to a number of stimuli with the help of 3 types of sense organs: epidermal receptor, buccal receptor, and photoreceptor. Figure: Sense organs of Earthworm. Image Source: Studio Biology. Epidermal receptors Distributed all over the epidermis but more abundant on …
The three-domain system was first introduced by Carl Woese in 1990 that is why its called Carl Woese’s Classification. This classification system also is known as the Six Kingdoms and Three Domains Classification because it divides the life forms into three domains and six kingdoms. The three-domains of Carl Woese’s Classification system …
What is the Plague? Plague, a term originally applied to any widespread disease which causes great mortality. The name is now confined to Bubonic Plague, an infectious disease of animals and humans caused by the bacterium Yersinia pestis. History In AD 541, the first great plague pandemic spread throughout the world from …
What are Aspirins? Aspirin is the precursor of traditional Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) and is the most commonly used salicylic acid derivative. Aspirin is considered as a standard to compare other anti-inflammatory agents. NSAIDs are a group of different chemical agents, that show differences in their antipyretic, analgesic, and anti-inflammatory activities. The …
Digestive System of Earthworm consists of the alimentary canal and the digestive glands. Image Source: https://digestivesystemgroup2.weebly.com/earth-worm-lumbricus-terrestris.html Earthworm Alimentary Canal Complete straight tube throughout the length of the body from mouth to anus. Mouth constitutes its anterior and anus its posterior openings receptively. Functionally regionated into various parts i.e. mouth and buccal chamber, …