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1. What do you mean by meiosis? Ans. Meiosis is a special type of cell division involving a diminution (meion in Greek means reduction or diminution) in the amount of genetic material which comprises two successive nuclear divisions with only one round of DNA replication, which produces four haploid daughter cells from an initial diploid [...]

It is the most powerful weather event on the earth, disrupting weather pattern across half of the earth’s surface. The most recent El Nino began to develop in 1989 and lingering until 1995. It resulted in unusual weather and short term climate changes that caused losses in crops and commercial fishing.

1. What are corals? Ans. Corals are the anthozoan polyps of Phylum Cnidaria, which are capable of secreting calcareous materials or a horny organic material that form a hard external or internal skeleton. 2. What is Corralite and Corralum? Ans. The skeleton formed by a solitary polyp is called Corralite, while the skeleton of entire [...]

Chemical oxygen demand (COD) is a measure of the ability of chemical reactions to oxidise matter in aqueous system. The results are expressed in terms of oxygen so that they can be compared directly to the results of biochemical oxygen demand (BOD) testing. The test is performed by adding the oxidising solution to a sample, [...]

The BOD test is an indirect measure of the biodegradable organic matter in an aqueous sample. The test is indirect because oxygen used by microbes as they degrade organic matter is measured. Generally the test is performed over a 5 day period (BOD5) of 20°C in 300 ml bottles incubated in the dark to prevent [...]

A large terrestrial or aquatic ecosystem characterized by distinctive kinds of plants and animals and maintained by a distinct climate and soil conditions. Such as the desert biome is characterized by low annual rainfall, high rate of evaporation, resulting in dry environmental conditions. Special adaptations allow organisms to survive in this condition. Other examples of [...]

1. Changes in glycosidation of lipids and proteins: The Golgi complex plays a central role in the biosynthesis of gangliosides and other glycosphingo lipids. There is evidence that in cancer cells, there are surface membrane changes that involve a loss of glycosphingo lipids and these alterations are due to the reduction of one or more [...]

1. Immortalization of cancer cell: Cancer cells are characterized by immortalization; they overcome apoptosis by altering the genes that control such death of the cell. Genetic expressions of certain genes make the malignant cells immortal. These two genes are oncogenes and tumor suppressor gene. Actually activation of protooncogene and inactivation of tumor suppressor genes both [...]

1. The tumor cells are much rounded in shape compared to normal cells. 2. Mitochondrial size is said to be smaller in cancer cells than the normal. In cancer cells, the alternation is extremely frequent mitochondrial swelling and it appears denser. Some granules are smaller than mitochondria, termed as growth granules, which are found only [...]

Cancer cells are defined by two heritable properties: they and their progeny (i) reproduce in defiance of the normal restraints on cell division and (2) invade and colonize territories normally reserved for other cells. The controlling mechanism in the cell proliferation is maintained by a chain of events. Very occasionally, this control breaks down. A [...]