Author Archives: Tejas Tapse

1 History of classification 1. Aristotle, the Greek philosopher, classified animals based on whether they live on land, in water or in the air. 2. Charles Darwin put forward the idea of evolution in 1859, in his book, The Origin of Species. 3. Ernst Haeckel, Robert Whittaker and Carl Woese have tried to classify livingContinue reading “Biological Classification-Quick Revision”

1 Characteristics of living organisms Characteristics of living organisms are as follows:1. Definite shape and size2. Organization (coordinated working of the body)3. Cellular organisation4. Growth and repair5. Spontaneous movement6. Nutrition (taking in and utilising food substances)7. Respiration (energy released for body functions)8. Excretion (throwing out of the body wastes)9. Sensitivity (response to external stimuli)10. MaintainingContinue reading “The Living World-Quick Revision”

Introduction to Reproduction in Organisms The time of birth to common death of a living being is called Life Traverse. No individual is everlasting with the exception of unicellular living being on account of it proceeds with its life traverse in descendants by fission. The coherence of life on earth is accomplished by the procedure of reproduction.Continue reading “Reproduction In Organisms”

Menstrual Cycle The reproductive cycle in female primates is known as the menstrual cycle. It starts at puberty which is referred to as menarche. Phases of the Menstrual Cycle The menstrual cycle has 4 phases: (1) Menstrual Phase: The menses take place on cycle days 3-5 in the menstrual cycle. The production of LH is reduced. This leads to degeneration ofContinue reading “what is Menstrual Cycle ?”

Gametogenesis is the process of formation of male and female gametes in the testes and ovary respectively. It is of two types: 1. Spermatogenesis – males 2. Oogenesis – females Spermatogenesis In testes, spermatogonia produce sperms by the process of spermatogenesis. This begins at puberty. Steps in Spermatogenesis The spermatogonia present at the inner side of seminiferous tubules multiply by mitotic division and increase in number. Each spermatogonium has 46 chromosomes. SpermatogoniaContinue reading “what is Gametogenesis ?”