GENERAL BIOLOGY st 1 Year GENERAL BIOLOGY Biology
GENERAL BIOLOGY st 1 Year
GENERAL BIOLOGY Biology & Molecular Basis of Life. Cell Structure & Functions. Introduction to Embryology. Basic Histology. Principles of Human Physiology.
I. BIOLOGY AND MOLECULAR BASIS OF LIFE Biology • The study of life. Details of Human Brain. The Composition of Genes. Functioning of Reproductive Systems. Human Genome. The sequence of DNA.
Theories Contributing Modern Biology The Cell Theory Evolution By Natural Selection Gene Theory Homeostasis All living things are made of one or more cells. Cells are the basic unit of structure and function in organisms. Cells originate from existing cells.
Theories Contributing Modern Biology The Cell Theory Natural Selection Evolution By Natural Selection Gene Theory Homeostasis The process of differential survival and reproduction of better genotypes that can be stabilizing, directional or disruptive. Better adapted individuals are more likely to survive to reproductive age and thus leave more offspring and contribute more to the gene pool. The differential survival and reproductive successes of individuals in a variable population maintain the evolutionary process. When all individuals survive and reproduce, natural selection works at lower rate.
Theories Contributing Modern Biology The Cell Theory Gene Theory Evolution By Natural Selection Gene Theory Homeostasis Genes are specific segment of DNA that control cell structure and function. Sequence of DNA bases usually code for a polypeptide sequence of amino acids. Genetic divergence is the separation of a population’s gene pools of other populations due to mutation, genetic drift and selection. Continued divergence can lead to speciation. Genetic map is a diagram showing the order of and the distance between genes.
Theories Contributing Modern Biology The Cell Theory Homeostasis Evolution By Natural Selection Gene Theory Homeostasis is the maintenance of a dynamic range of conditions within which the organism can function. Temperature, PH and energy are major components of this concept. Thermodynamics is the field of study that covers the laws governing energy transfers. The universe is composed of two things: matter (atoms, molecules, organelles and cells) and energy.
The Diversity of Life
Organization To Environment or each others. External or internal. Organization into cells, organelles and molecules. Interactions Response to stimuli From sunlight, inorganic chemicals or another organisms. Release in the form of ATP. The maintenance of a constant internal environment (temp, PH, water concentration). Homeostasis Characteristics of living organisms Energy Acquisition and release Single cells grow to mature cells for division. Multicellular organisms more complicated (Differentiation and Organogenesis). Adaption Reproduction Growth and Development Living things are suited to their mode of existence. Since all cells come from existing cells, they must have some ways to reproduce (asexual or sexual).
Levels of Organization Biosphere • The sum of all living things taken in conjunction with their environment. Ecosystem • The relation of a smaller group of organisms with each others and their environment. Community Species • The relation between groups of different species. Like dessert communities consists of rabbits, snakes and such dessert plants as cactus. • Group of similar individuals who tend to mate and produce viable, fertile offspring. Population • Group of similar individuals who tend to mate with each others in a limited geographic area. Individuals • One or more cells with a unique DNA arrangement. • These can be unicellular or multicellular.
Levels of Organization Organ System • In multicellular organisms. • A group of cells, tissues and organs performing a specific major function. Like cardiovascular system. Organ • In multicellular organisms. • A group of cells or tissues performing an overall function. Like heart. Tissue • In multicellular organisms. • A group of cells performing specific functions. Like heart muscle tissue. Cell • The fundamental unit of live things. • Each cells has DNA, energy acquiring chemicals and structures. organelles • A subunit of a cell, subcellular function. like ribosomes (protein synthesis), Mitochondria (ATP generation). Molecules • The fundamental functional levels of biochemistry.
Atoms Universe (energy & matter), Matter (Elements), Elements (atoms). Nucleic acids Molecules DNA and RNA 50 -60% of dry mass of a cell. Composed: amino acids. Function: structure and enzymes. Molecular basis of life Proteins 40% of dry mass of cell. From: carbon and hydrogen. Insoluble in water. Structural component. Lipids 3% dry mass of cell. Composed: carbon, hydrogen and oxygen atoms. Important source of energy. Water Ions Carbohydrates Are compounds in which the elements are definite, fixed ratios. 60 -90% living organisms. Excellent solvent & Metabolite reactions. Atoms or molecules with unequal no. of electrons or protons.
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