In this article we will discuss about the determination of LC50 and LD50 of toxicants. Determination of LC50: Different procedures are adopted depending on the size of the organisms subjected to a toxicant. Mosquito Larvae (Test Animal): Four 1000 ml glass beakers are half-filled with tap water/tank water. A measured amount of toxicant-liquid/solid—is thoroughly mixed with water in three beakers—1, [...]
In this article we will discuss about the water sample collection for physical and chemical analysis. I. Collection of Water Sample: A representative sampling is usually done by collecting samples from a number of places from different depths and mixing them together to get a composite sample. A Kemmerer, Friedinger or Forest type sampler is used for water collection. Bubbling [...]
In this article we will discuss about the structure of different vertebrata. Skull: 1. Presence of cranium, sensory capsules, foramen magnum and jaws. Ready identification: Identification: Skull Bufo, Rana: Subphylum Vertebrata: 1. Cranium bony or cartilagenous and encloses a cavity. 2. Cranium constituted by three rings— occipital, parietal and frontal. 3. Sense capsules—olfactory, optic and otic. 4. Foramina for cranial [...]