BSCI105 Chapter 1 Evolution The Theme of Biology Scientist Inquiry 1 25 16 6 18 PM Evolution process of change that has transform life on Earth from its earliest beginnings to the diversity or organisms living today Properties of Life order evolutionary adaptation regulation reproduction response to the environment energy processing Levels of Biological Organization Biosphere consist all life on Earth Ecosystems living things in a particular area with nonliving things Communities array of organisms inhabiting a part of an ecosystem Population all individuals of a species in an area Organisms individual living things Organs and Organ Systems multiple tissues Tissues group of cells that work together Cells fundamental unit of structure function Organelles functional components present in cells Molecules chemistry structure consisting of 2 or more units called atoms Emergent Properties are due to the arrangement and interactions of parts as complexity increases In other words in order for something to happen there must be organization and a specific arrangement Systems biology explore emergent properties the exploration of a biological system by analyzing the interaction among its parts Structure Functions Knowing the structure will let us know what it does and how it works and vices versa 1 2 The Cells An Organism s Basic Unit of Structure Function Every Cell is enclosed by a membrane that regulates the passage of materials between the cells its surroundings Prokaryotic cells cells of 2 groups of single celled organisms Bacteria and Archaena Eukaryotic cells other forms of life such as plants and animals Genetics Chromosomes contain genetic material in form of DNA deo Cell division DNA is replicated and each cellular offspring inherits a complete set of chromosomes identical to the parent DNA o Made up of 2 long chains strands o Arranged in a double helix o Each chain is made up of 4 chemical building blocks called nucleotides A T G C Many genes provide the blueprints for making proteins which are a major player in building and maintaining cell and activities Genes control protein production indirectly using RNA o The sequence of nucleotides along a gene is transcribed into RNA which is then translated into linked series of protein building blocks called amino acids Gene expression entire process by which the info in a gene directs the manufacture of a cell product Genetic code particular sequence of nucleotides says the same thing in 1 organism as it does in another RNA manufactures proteins regulate the function of protein coding genes Analysis of DNA Sequence Genome entire library of genetic instructions that an organism inherits Genomics researchers study whole sets of genes in 1 or more species Proteomics study of sets of proteins their properties Proteome entire set of proteins expressed by a given cell group of cells 3 important research developments have made genomic proteomic approaches possible high throughput technology tools that can analyze many biological samples quickly bioinformatics use computational tools to store organize and analyze the huge volume of data that results from high throughput methods formation of interdisciplinary research teams groups of diverse specialists such computer scientists Life Requires the transfer transformation of Energy Matter Energy primarily from the sun and then transferred from one form to another from plant to mathematicians etc consumers Energy is lost to the surroundings in a form of heat Energy is a one way flow Enter from light and exit as heat Chemicals are recycled within an ecosystem o Plants absorb chemicals from air sun and soil consumers receive chemicals from eating plants chemicals are returned to the environment by decomposers From Ecosystems to Molecules Interactions are important in biological systems Ecosystems an organism s interactions with other organisms and the physical environment Molecules interactions within organisms o The molecules inside the organism interact with one another to maintain the body s balance such as glucose level Feedback regulation the output or product of a process regulates that very process o Negative feedback response reduces the initial stimulus o Positive feedback end product speeds up its own process Evolution adaptation of organisms to their environments the concept that the organisms living on Earth today are modified descendants of common ancestors 1 3 Evolution Accounts for the Unity and Diversity of Life 1 8 millions species named by scientists o 100 000 fungi 290 000 plants 57 000 vertebrate 1 million insects other single cell organisms o 10 100 million species estimated exist on Earth Grouping species o Taxonomy branch of biology that names classifies species into groups based on similar o Kingdom Domains broadest units or classification characterizes 3 domains Bacteria most diverse and widespread Archaea live in extreme environments Eukarya 3 kingdoms based on their modes of nutrition Plantae photosynthesis Animalia eating and digesting Fungi absord dissolved nutrients from surrounding and Protists unicellular eukaryotes which are more similar to plants animals and fungi than other protists so they are split into several other kingdoms o Similarities between organisms are evident in all levels of the biological hierarchy Charles Darwin the theory of Natural Selection On the Origin of Species by Means of Natural Selection o Contemporary species arose from a succession of ancestors that differed from them descent with modification Unity in the kinship among species that descended from common ancestors diversity in the modifications that evolved as species branch from common ancestors o Natural selection evolutionary mechanism for descent with modification evolutionary adaptation The natural environment selects for the propagation of certain traits among naturally occurring variant traits in the population In other words individuals with inherited traits that are better suited to the local environment are more likely to survive reproduce than less suited individuals The Tree of Life descendants Each branch point represents the common ancestor of evolutionary lineages originating there and their One population fragments into several subpopulations isolated in different environment In separate areas of natural selection one species could gradually radiate into multiple species as the geographically isolated populations adapted over many generations 1 3 In studying Nature
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