Week 1 - Chapter 1 Biology - study of life Study of plants - botany Study of animals - zoology Study of microorganisms - microbiology Study of viruses - virology Study of bacteria - bacteriology Study of fungi - mycology Study of genes - genetics Study of classification of organisms - taxonomy Study of cells - cytology Study of structure and function of organs and organ systems - anatomy and physiology Study of how organism interact with their environment - ecology What is life (key properties) Common characteristics - Arranged in a particular order -structure - Acquire and use materials and energy - Actively maintain organized complexity - Perceive and respond to stimuli - Grow and reproduce - Regulate their internal environment - homeostasis - Have the capacity to evolve, collectively - Evolutionary adaptation Cell is the basic/smallest unit of life - It is separated from its surroundings by a membrane Energy acquire and use in ecosystem In most ecosystems - Plants are the producers that provide the food - Consumers eat plants and other animals - Decomposers act as recyclers, changing complex matter into simpler mineral nutrients Producers Organisms obtain energy in two ways. Coming directly of indirectly from the sun - Photosynthesis is the process by which plants and some single-celled organisms capture sunlight - Other organism consumer energy rich molecules in the bodies of other organisms - Also known as autotrophs - Examples: plants and blue green bacteria, phytoplankton Consumers - Organisms obtaining energy form complex organic substances - These cannot produce its own food, instead take nutrition from other sources of organic carbon, mainly plant or animal matter - In a food chain there can be primary, secondary and tertiary consumers - Also known as heterotrophs - Examples: bacteria, animals Decomposers - Decomposers are organism that break down dead or decaying organisms - Detritivores ingest and digest dead matter internally, while decomposers directly absorb nutrients through external chemical and biological processes - Earthworms are technically detritivores, not decomposers, since they must ingest nutrients because they are unable to absorb them externally In an ecosystem - Energy flows in one direction, nutrients are recycled Life-organized complexity - organisms actively maintain organized complexity Life- response to stimuli Organisms perceive and respond to stimuli - Organisms sense and respond to internal and external environmental stimuli - - sensory organs in animals can detect and respond to external stimuli such as light, sound, chemicals, etc - Internal stimuli in animals are perceived by a stretch, temperature, pain, and chemical receptors - Plants and bacteria respond to stimuli as well, such as plants turning to face light and bacteria moving toward nutrients Life-growth Organisms grow - Every organisms becomes larger over time - Plants, birds, and mammals grow by producing more cells to increase their mass - Bacteria grow by enlarging their cells; they divide in half to reproduce after genetic material is copied Life-reproduction Organisms reproduce - Organism reproduce by dividing in half, producing seeds, bearing live young and leggings eggs - Sperm and egg combine to form zygote - Organisms give rise to offspring of the same type - The parents genetic material (DNA) is passed on to the offspring creating continuity of life DNA - Deoxyribose Nucleic Acid - Found in every cell - Carries genetic information - Humans are 99.1% similar to each other Life-evolution - Organisms, collectively, have the ability to evolve - Evolution is the process by which modern organisms ascended, with modifications, from preexisting forms of life - Changes in DNA within populations occur over the course of generations, which results in evolution Life-adaptations - Adaptations are structures, physiological processes, or behaviors that aid in survival and reproductions - Adaptations that good for one environment may be poor in another - Species that cannot adapt to environmental change become extinct, as for example the dinosaurs - Extinction is the complete elimination of a species How do scientist study life - life's levels of organization Life can be studied at different levels - Matter is formed of elements - An atom is the smallest particle of an element retaining the properties of an element - An atom is the smallest unit that makes up life, but does not have life - Atoms combine to form molecules - Molecules provide the building blocks of life Some forms of life consist of single cells - In multicellular forms, cells combine to form tissues - Tissues must be made up of the same type of cells - Tissues combine to organs which can be united as organ systems - Organ systems make multicellular organisms Life can be studied at different levels - Organisms of the same type that are capable of interacting and interbreeding are called species - A group of organism of the same species living in a given area is a population - Interaction populations make up a community - A community and its nonliving environment is an ecosystem - The entire surface of earth including living and nonliving components is the biosphere Levels of organization - Atoms - Molecules - Macromolecules - Organelles - Cells - Tissues - Organs - Organ systems - Organism - Populations - Communities - Ecosystems - Biosphere Classification of organisms Scientist generally categorize organism into three major groups - Archaea - Eukarya - bacteria Bacteria and archaea are unicellular organisms and eukarya can be multicellular or unicellular Unicellular - prokaryotes Archaea live in extreme environments and can never cause diseases in animals Bacteria can cause diseases because they live in many different environments The cells of the domain can be classified as prokaryotes or eukaryote Prokaryotes - Were the first to evolve - Lacks a nucleus - Are simpler - Are usually smaller than eukaryotic cells - Examples - bacteria and archaea - Bacteria cell wall - perptilogycan Eukaryotes - Contain membrane enclosed organelles including a nucleus containing DNA - Are found in plants animals protist and fungi Types of eukaryotic cells Animals - No cell wall - Ingest their meals and digest them internally Plants - Have cell wall made of cellulose - Obtain energy by photosynthesis - Can make their own food and are autotrophs Protists - Most are unicellular - Very diverse species; examples are algae, malarial parasites Fungi - All fungi are multicellular except yeast - Have cell walls made up of chitin - Obtain energy by secreting digestive enzymes and absorb the broken products Chapter 2 Life is composed of matter Matter - Occupies space - Has mass - Is composed of elements Elements are unique forms of matter - Has specific chemical properties - Has specific physical properties - Found in the periodic table Elements cannot be broken down Each element is represented by a letter or two Four most common elements of living things - Carbon C - Oxygen O - Hydrogen H - Nitrogen N Atoms are the smallest unit of matter that retains the chemical properties of an element Contains two regions - Nucleus - center of the atom and contains protons and neutrons - Outermost region - holds electrons in orbit around the nucleus Protons, neutrons, and electrons are referred to as subatomic particles Protons are positive, neutrons are neutral and electrons are negative Atoms of each element have a standard number of proteins and electrons - Atomic number is the number of protons - mass number is the number of protons and neutrons Atomic mass is the mass of the atom, roughly equal to number of protons and neutrons (mass number) Atomic mass=mass number Isotopes are the same elements but with different numbers of neutrons Substances that dissolve in water are called polar or hydrophilic Substances that do not dissolve in water are called non polar substances or hydrophobic Solute and solvent together make a solution Blood is a solution Water boils at 100C 212F Water freezes at 0C 32F Water-soluble substances are called polar Water dreading substances are nonpolar Oil is hydrophobic Oil is non polar Sugar is hydrophilic Sugar is polar Ph of blood is 7.38-7.42 Chapter 4 Prokaryotic cells do not have a nucleus Eukaryotic cells have a nucleus Structure of the cell membrane? Two layers of phospholipids with hydrophilic heads facing out and hydrophobic tails on the inside of the heads DNA to RNa - transcription RNA to proteins - translate Entire process -
