Online Biology Notes for students
1. Food Paramecium feeds in a holozoic manner, like an amoeba. The food comprises chiefly bacteria and minute protozoa which floats in the water in which it lives. It also feeds unicellular plants (algae, diatoms, yeasts, etc.) and small bits of animals and vegetables. Paramecium swims to a place where it can …
Habit and Habitat Paramecium caudatum (Gr., paramekes=oblong+ L., caudata=tail) is a free-living organism which is one of the most common species of Paramecium having worldwide distribution. It is commonly found in freshwater, ponds, pools, ditches, streams, lakes, reservoirs, and rivers. It is usually found abundant in water containing decaying organic matters, in …
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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 …
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, …