Biology is the branch of science, where bio means life and logy means to study, basically biology is defined as the study of life, divided into two main branches, ZOOLOGY, 'study of animal life', BOTANY, 'study of plant life'.
From its earliest beginnings, biology has wrestled with some questions: What is the shared properties that make something “alive”? How do those various living things function? When faced with the remarkable diversity of life, how do we organize the different kinds of organisms so that we can better understand them? Concepts that are described in biology give away many answers, and, As new organisms are discovered every day, biologists continue to seek answers to these and other questions.
The biological levels of organization range from a single organelle all the way up to the biosphere in a highly structured hierarchy.
The diversity of life can be classified within the three major domains (Bacteria, Eukarya and Archaea) using phylogenetic trees.
Key characteristics or functions of living beings are ordered, stimuli, reproduction, growth/development, regulation, homeostasis, and energy.
Organisms grow and develop according to specific instructions coded for by their genes, these genes provide instructions that will direct cellular growth and development, ensuring that a species will grow up to exhibit many of the same characteristics as its parents.
Even the smallest organisms are complex and require multiple regulatory mechanisms to coordinate internal functions, such as the transport of nutrients, response to stimuli, and coping with environmental stresses.
All organisms use a source of energy for their metabolic activities. Some organisms capture energy from the Sun and convert it into chemical energy in food; others use chemical energy from molecules they take in.
To function properly, cells require - appropriate conditions such as proper temperature, pH, and concentrations of diverse chemicals.
Single-celled organisms reproduce by first duplicating their DNA, which is the genetic material, and then dividing it equally as the cell prepares to divide to form two new cells. Many multicellular organisms (those made up of more than one cell) produce specialized reproductive cells that will form new individuals.
All living organisms exhibit a “fit” to their environment, a consequence of evolution by natural selection, which operates in every lineage of reproducing organisms. Examples of adaptations are diverse and unique, All adaptations enhance the reproductive potential of the individual exhibiting them, including their ability to survive to reproduce.
Immunity is the balanced state of having adequate biological defenses to fight infection, disease, or other unwanted biological invasion while having adequate tolerance to avoid allergy and autoimmune diseases.