Exploring Life

The great variety of species that exist today on our planet evolved over a period of time. The environment and the biological evolution are closely related leading to rich diversity of life. The evolution of photosynthetic organisms that released oxygen into the air, followed by emergence of homo sapiens transformed the life on earth. Some of the important properties and processes that associate with life are ordered structure, evolutionary adaptation, response to the environment, regulation, energy processing, growth and development and reproduction. Flow of energy from sunlight and the feedback mechanisms in biological systems sustain life. Exploring life in its entirety starts from the microscopic molecules and cells that make up organisms to the macroscopic view of entire planet including the biosphere and ecosystems. Biosphere includes most regions of land, bodies of water such as lakes, rivers and oceans and the atmosphere to an altitude of several miles.  Diversity is the hallmark of life as the total species count range between 10 million to 200 million while biologists have so far named about 1.8 million species which can be grouped under three domains or five kingdoms. Even though there is so much of diversity we can also find remarkable unity especially at molecular and cellular levels. The universal genetic language of DNA is common to organisms as different as bacteria and animals. Darwin’s theory of evolution by way of descent with modification and natural selection explains this unity and diversity. The rain forest orchids reflect the unity in diversity through variations in their form and colour while all of them belong to the same species with common characteristics such as lip like petals that attract pollinating insects and provides a landing platform for the pollinators. Exploring life in its entirety helps us to have a panoramic view of the unity in the diversity of life. For More Detailed Knowledge on this Topic Visit  wonderwhizkids/Biology/Exploring Life

Genetics

Genetics, a discipline of biology, is the science of heredity and variation in living organisms. The continuity of life depends on the inheritance of biological information in the form of DNA molecules. The research kindled by curiosity about the origin and nature of life, lead to breakthroughs in genetics and cell biology. The discoveries are certainly going to transform medicine and improve our quality of life. Knowledge of the inheritance of characteristics has been implicitly used since prehistoric times for improving crop plants and animals through selective breeding. However, the modern science of genetics, which seeks to understand the mechanisms of inheritance, only began with the work of Gregor Mendel in the mid–1800s. Although he did not know the physical basis for heredity, Mendel observed that inheritance is fundamentally a discrete process with specific traits that are inherited in an independent manner – these basic units of inheritance are now called genes. Following the rediscovery of Mendel’s observations in the early 1900s, research in 1910s yielded the first physical understanding of inheritance – that genes are arranged linearly along large cellular structures called chromosomes. By the 1950s it was understood that the core of a chromosome was a long molecule called DNA and genes existed as linear sections within the molecule. A single strand of DNA is a chain of four types of nucleotides; hereditary information is contained within the sequence of these nucleotides. Solved by Watson and Crick in 1953, DNA's three–dimensional structure is a double–stranded helix, with the nucleotides on each strand complementary to each other. Each strand acts as a template for synthesis of a new partner strand, providing the physical mechanism for the inheritance of information. Find More knowledge base on wonderwhizkids/Genetics