General Biology Bio 110 Chapter 1 PDF

General Biology Bio 110 Chapter 1 CONTENTS: Part 1 Life on Earth: An Overview Chapter 1 PART II Chemistry of Life a. Basic Chemistry Chapter 2 b. Chemistry of Organic Molecules Chapter 3 PART III The...

General Biology Bio 110 Chapter 1 CONTENTS: Part 1 Life on Earth: An Overview Chapter 1 PART II Chemistry of Life a. Basic Chemistry Chapter 2 b. Chemistry of Organic Molecules Chapter 3 PART III The Cell a. Cell Structure and Function Chapter 4 b. Membrane Structure and Function Chapter 5 CONTENTS: PART IV Microbiology Chapter 6 PART VI Plant Chapter 7 PART VII Animal Chapter 8 PART IX Genetics Basic of Life a. Genetic Control and Cell Cycle Chapter 9 b. Classical Genetics and Modern Chapter 10 Biotechnology.  Part 1.1 1.1 LIFE ON EARTH An Overview PART I: LIFE ON EARTH: An Overview 1.1 HOW TO DEFINE LIFE a. Life is Plentiful and Diverse b. Levels of Biological Organization c. Acquirement of Materials and Energy and Homeostasis d. Behavior of Living Things e. Reproduction of Living Things 1.2 Adaptation and biodiversity of Living Things a. Organizing Diversity 1. Domains 2. Scientific Name b. Natural Selection c. Biodiversity Part 1: Introduction to Biology The term “Biology” has been derived from bios = life and logos = science It is the scientific study of all living things, called organisms. Organisms include bacteria, protists, fungi, plants, & animals  1.1 How to Define Life Life on Earth exists in different forms and varieties. Humans share the planet with as many as 8.7 million different forms of life, according to what is being billed as the most accurate estimate yet of life on Earth. Organisms or living things behave in ways different from those of humans: The Antarctic blue whale is the biggest animal on the planet, weighing up to 400,000 pounds (approximately 33 elephants) and reaching up to 98 feet in length. The smallest known adult insect is a parasitic wasp, Dicopomorpha echmepterygis. These tiny wasps are often called fairyflies. Males are wingless, blind and measure only 0.005 inches (0.127 mm) long. Some bacteria’s life is 15 minuets, while some pine trees outlive as long as ten generations of human. 1.1 How to Define Life Living things (organisms) as well as non-living things are composed of chemical elements and obey the same universe laws of chemistry and physics of life (Figure 1.1). Organisms can be distinguished by how they get their food: Fungus digests its food externally by absorption. Sunflower, a photosynthetic plant, makes its own food. Snow goose, an animal, ingests its food. Figure 1.1 Diversity of life on Planet Earth. b. Levels of Biological Organization, Moving up the Hierarchy: Atoms: the basic units of matter. Molecules: cluster of atoms. Organelles: membrane bounded structures with different jobs inside the cell. The cell, life starts here, the simplest entity that has all prosperities of life. Tissue: Made of groups of similar cells that carries out a particular function on an organism. Organs: a structure consisting of two or more tissues that perform specialized functions on an organism. Organ system: have specific functions ; are composed of organs that carries out a particular function in an organism. Organism: An individual living thing that can react to stimuli, reproduce, grow, and maintain homeostasis. b. Levels of Biological Organization, Moving up the Hierarchy:  Population: All the individuals of a species that interbreed with each other within a specific area.  Community: the array of organisms ( different populations) living in particular ecosystem.  Ecosystem: All the organisms ( communities) living in particular area.  Biosphere: All the environments ( ecosystems) on earth the support life. b. Levels of Biological Organization c. Acquirement of Materials and Energy and Homeostasis: -Food provides nutrients, which are used as building blocks or for energy (Figure 1.3). Energy is the capacity to do work. When cells take nutrient molecules, they carry out a sequence of chemical reactions through metabolism. The ultimate source of energy for all life on Earth is the sun. Plants and certain other organisms can capture solar energy and carry-on photosynthesis, eg., transform solar energy into the chemical energy. Figure 1.3 c. Acquirement of Materials and Energy and Homeostasis: Organism’s ability to maintain a state of biological balance is called homeostasis. For life to continue, temperature, moisture level, acidity and other physiological factors must remain within the tolerance range of the organism. Control mechanism; eg., when you forget to eat, your liver releases stored sugar to keep blood sugar levels within normal limits. Figure 1.3 d. Behavior of Living Things: Multicellular, rather than unicellular organisms, can manage more complex responses. The ability to respond often results in movement; eg., Leaves of a plant turn toward the sun. These activities are termed behavior of the organism to maintain homeostasis and search and compete for: Energy Nutrients Shelter Mates e. Reproduction of Living Things: Life comes only from life. Every type of living thing can reproduce; make another organism like itself (Figure 1.4). Bacteria and protists split in two. Most multicellular organisms reproduce by pairing of a sperm from one partner and an egg from the other partner to form an embryo. Then, many cell divisions take place and organism grows to become an adult. When living things reproduce, their genes are passed on to the next generation. DNA, over time, also undergoes mutations (changes) that may be passed on to the next generation. These events help to Figure 1.4 Penguins with their create diversity of life. offspring.  Part 1.2 1.2 Adaptation and Biodiversity of Living Things 1.2 Adaptation and Biodiversity of Living Things Adaptation is the modifications that make organisms better able to function in a particular environment, ex.: Penguins are adapted to an aquatic existence by an extra layer of short, thick feathers that form a waterproof coat. They also slide on their bellies across the snow in order to conserve energy when moving quickly. Camels have many adaptive traits for their life in the desert. They have wide feet for walking on sand. They have long eyelashes and thin slit nostrils that they can close to protect them from blowing sand. They are adapted to survive a long time without water and food. - The unity of living things suggests that they are descended from a common ancestor—the first cell (Figure 1.5). Figure 1.5 Evolutionary tree of life. a. Organizing Diversity: Taxonomy is the discipline of identifying and grouping organisms according to certain rules. Several of the basic classification categories, or taxa going from least to most inclusive are species, genus, family, order, class, phylum, kingdom and domain (Table 1.1). Species is defined as a group of interbreeding individuals. Species placed within one genus share many specific characteristics and are the most closely related, while species placed in the same Family share only general characteristics.  SYSTEMATICS a. Linnaean Taxonomy At the seventeenth century, it was believed that each organism should have a set name. During this time, Carolus Linnaeus (1707-1778) developed binomial nomenclature, by which each species receives a two-part name. For example, Lilium canadense and Lilium bulbiferum are two different species of lily (Figure 6.1). The first word, Lilium, is the genus (pl. genera), a classification category that can contain many species. The second word, the specific epithet, refers to one species within that genus. The scientific name is in italics; the genus is capitalized, while the specific epithet is not. Both names are separately underlined when handwritten. Figure 6.1 Lily species. SYSTEMATICS a. Linnaean Taxonomy The specific epithet alone gives no meaning—just as the house number alone without the street name gives no meaning. The genus name can be used alone to refer to a group of related species. Also, the genus can be abbreviated to a single letter if used with the specific epithet (e.g., L. bulbiferum) and if the full name has been given previously. Scientific names are derived in several ways: Some scientific names are descriptive in nature, ex., Acer rubrum for the red maple, ( Acer= maple, and rubrum= Red) Other scientific names may include geographic descriptions such as Alligator mississippiensis for the American alligator. Scientific names can also include eponyms (named after someone), such as the owl mite Strigophilus garylarsonii (named after the cartoonist, Gary Larson). SYSTEMATICS a. Linnaean Taxonomy Why do organisms need scientific names? And why do scientists use Latin, rather than common names, to describe organisms? common name varies from country to country because different countries use different languages. even people who speak the same language sometimes use different common names to describe the same organism, ex., bowfin, grindle, choupique and cypress trout describe the same fish, Amia calva. Furthermore, between countries, the same common name is sometimes given to different organisms. A “robin” in England is very different from a “robin” in the United States, for example. Latin, on the other hand, is a universal language that not too long ago was well known. When scientists throughout the world use the same scientific binomial name, they know they are speaking of the same organism.  SYSTEMATICS a. Linnaean Taxonomy (cont.) It is estimated that there are 30 million species now living on Earth. The task of identifying and naming the species of the world is continuing. The latest fast and efficient way of identifying species is based on their DNA. This molecular method was found satisfactory for the identification of mosquito species in India. SYSTEMATICS: b. Linnaean Classification Categories: In the context of classification, a species is a taxonomic category below the rank of genus. The taxonomist Aristotle divided living things into 14 groups— mammals, birds, fish and so on. Then, he subdivided the groups according to the size of the organisms. Ray used a more natural system, grouping animals and plants according to how they were related. Linnaeus simply used flower part differences to assign plants to the categories species, genus, order and class. Nowadays, taxonomists use the following major categories of classification: species , genus, family, order, class, phylum, kingdom Recently, a higher taxonomic category, the domain, has been added to this list; Bacteria, Archea, and Eucaria respectively. SYSTEMATICS: b. Linnaean Classification Categories: There can be several species within a genus, several genera within a family and so forth—the higher the category, the more inclusive it is (Figure 6.2). Therefore, there is a hierarchy of categories. SYSTEMATICS: b. Linnaean Classification Categories You can also say that the categories are nested. For example, a domain contains many kingdoms and one kingdom contain many classes, and so forth. Organisms in the same domain have general traits in common; those in the same species have quite specific traits in common. In most cases, categories of classification can be subdivided into three additional categories, as in superorder, order, suborder and infraorder.  1.2 Adaptation and Biodiversity of Living Things: a. Organizing Diversity I. Domain Biochemical evidence suggests that there are only three domains: 1- Bacteria (Figure 1,6) 2- Archaea (Figure 1.7). 3- Eukarya Both domains Bacteria and Archaea evolved from the first common ancestor soon after life began. They are prokaryotes, which lack the membrane-bounded nucleus found in the eukaryotes of domain Eukarya. Archaea’s cell walls & membranes are chemically more similar to eukaryotes than bacteria. Figure 1.7 Domain Archaea. Figure 1.6 Domain Bacteria. 1.2 Adaptation and Biodiversity of Living Things: Organizing Diversity : The three-domain system: 1- Domain Bacteria: Bacteria are so diversified and plentiful as they are found in large numbers nearly everywhere on Earth. Bacteria differ from the archaea not structurally but biochemically (Table 6.1). All forms of nutrition are found among the bacteria, but most are heterotrophic. Heterotrophic bacteria are beneficial in ecosystems because they break down organic remains.  The Three-Domain System: b. Domain Archaea: Like bacteria, archaea are prokaryotic unicellular organisms that reproduce asexually. Archaea don’t look different from bacteria under the microscope, but they are distinguishable from bacteria by a difference in their rRNA base sequences and also by their unique plasma membrane and cell wall. chemistry (Table 6.2). Archaea can live in aquatic environments that lack oxygen or are too salty, too hot, or too acidic for most other organisms, perhaps Archaea are the least evolved forms of life. (Figure1.8) Table 6.1 Figure 1. 8 Domain Archaea ( extreme environment)  The Three-Domain System 2. Domain Archaea (continued): The branched nature of diverse lipids in the archaeal plasma membrane, for example, could possibly help them live in extreme conditions. Ex., the halophiles are salt lovers living in bodies of water such as the Great Salt Lake in Utah; and the thermoacidophiles are both high temperature and acid loving. Table 6.2 The Three-Domain System 3- Domain Eukarya: Domain Eukarya contains four major groups of organisms: A- Protists, range from unicellular (Figure1.9a) to a multicellular forms. Some are Figure 1.9 a Domain Eukarya. photosynthesizing, ex. algae. B- Fungi, the familiar molds and mushrooms that help decompose dead organisms (Figure 1.9b). C- Plants, multicellular photosynthetic organisms. Figure 1.9 b Domain Eukarya. D- Animals, multicellular organisms that must ingest and process their food.  b. Natural Selection: Natural selection is the process that made modification, or adaptation, possible, where some aspect of the environment selects which traits to be passed on to the next generation Figure 1.9 shows how the dietary habits of deer affect the characteristics of the leaves of a particular land plant; though mutations. How? A plant species generally produces smooth leaves, but an advantageous mutation occurs to cause one plant to have hairy leaves, while the deer (the selective agent) prefer to eat smooth leaves. Then, the plant with hairy leaves survives best and produces more seeds than most of its neighbors. Figure 1.9 Natural selection. c. Biodiversity: Biodiversity is the total number and relative abundance of species, the variability of their genes and the different ecosystems in which they live. The present biodiversity of our planet has been estimated to be as high as 15 million species and so far, less than 2 million have been identified and named. Extinction is the death of a species or larger classification category. It is estimated that presently we are losing as many as 400 species per day due to human activities. For example, several species of fishes disappeared from the coral reefs of Indonesia and along the African coast because of overfishing. The last mass extinction, about 65 million years ago, caused many plant and animal species, including the dinosaurs, to become extinct. It would seem that the primary bioethical issue of our time is the preservation of ecosystems. Thank you