Author: Harjeet Kaur
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Entamoeba histolytica
(Anaerobic parasite) Causes Amoebic dysentery or Amoebiasis. Distribution: Worldwide. Habits & Habitat: Found in large intestine (colon) of man, in both mucosal & sub-mucosal layers of it. It feeds on tissue and RBCs mainly. Secrete a toxic substance to dissolve mucous lining of the intestine. It gradually recedes deep in the mucosal & sub-mucosal…
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Introduction to Parasitology (Related Terminology)
Parasitology Parasitology is the study of parasites and their relationship with their host. Parasitism Parasitism is a type of symbiotic relationship between two heterospecific organisms in which one organism called the parasite is metabolically dependent on the other called the host. The parasite benefits at the expense of the host and is also usually smaller…
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Ecological Factor: Temperature
Introduction Compared to excessively wide range of temperatures existing in this universe, life is known to exist in very narrow range of temperature only. This in itself indicates that temperature has significant effect on living organisms as a limiting factor. Temperature regulates all chemical processes & many physical processes. It controls feeding, respiration, growth, reproduction,…
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Abiotic Factors
Abiotic Factors Abiotic factors are the non-living factors in our environment that affect living organisms & ecosystems. Example: Temperature, light, humidity, atmosphere, soil etc. Ecophysiology (Physiological Ecology) Ecophysiology is the part of ecology which is concerned with responses of individual organisms or species to abiotic factors. Types of Abiotic Factors we are going to study…
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Food Chain & Food Web
Food Chain Transfer of food energy from source (producer) to organisms consuming it (primary consumers) & further these organisms in turn are eaten up by organisms to which they are food source (secondary consumers) and so on, in a linear series. Types of Food Chains: Grazing Food Chain: Starts from living green plants (producers). The…
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Speciation (Formation of new species)
Definitions: Species: It is a group of organisms which can interbreed and produce fertile offspring. A species shares a common gene pool. Speciation: It is the formation of new species and diversification of species. It occurs when the common gene pool shared by a species is interrupted by isolating mechanisms. Modes of Speciation: Phyletic Transformation:…
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Major Ecosystems of the World
Overview Types of Ecosystem Artificial categorization of ecosystem can be done as following of the giant ecosystem – the Ecosphere. A) Natural Ecosystems: Self- operated under natural conditions. Natural ecosystems can be further classified as… Terrestrial- for example: Forest, Grassland, Desert, Natural Geysers etc. Aquatic- Further classified as freshwater & marine… Freshwater- Lotic (Running water):…
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Ecology: Definition, Subdivision & Scope of Ecology
The word ecology is derived from Greek language… So for an idea of Ecology, it can be said that it is study of the environmental house including all the organisms living in it & all the functional processes occurring inside it. That means we can say that ecology is basically concerned with study of relationship…
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Ecosystem Structure
On the basis of trophic structure, ecosystem is two layered: “trophe = nourishment” Autotrophic Stratum (Green Belt): Upper, self-nourishing layer of chlorophyll-containing plants. Fix the light energy, convert inorganic substances into complex organic compounds which predominate in the stratum. The most intensive autotrophic metabolism occurs in this layer where light energy is available. Heterotrophic Stratum…
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Ecosystem (Introduction)
Introduction Ecosystem = Ecological System (Eco = Environment; System = Interacting & interdependent complex) ‘Ecosystem’ term was first used by A.G. Tansley (1935), describing a natural unit consisting of both living & non- living parts, which interact, forming a stable system. Fundamental concepts of ecosystem include… Energy flow through food chains or food webs. Nutrient…