BIOL 1000 Chapter 1 Lecture Outline New Format FA2024 PDF

MACOMB COMMUNITY COLLEGE BIOL 1000 Chapter 1 Biology: The Study of Life What is biology? – the study of living things Some common biological terms organisms - living things (unicellular or multicellular) species – a type of organism diversity of life – there are many dif...

MACOMB COMMUNITY COLLEGE BIOL 1000 Chapter 1 Biology: The Study of Life What is biology? – the study of living things Some common biological terms organisms - living things (unicellular or multicellular) species – a type of organism diversity of life – there are many different types of organisms on earth With this diversity, there is a unity of life because all organisms share common traits such as consisting of cells and performing metabolism. What is life? (characteristics of living things) The basic unit of life is the cell. metabolism – sum of all the chemical reactions in an organism and within its cells homeostasis – the maintenance of a constant, internal environment e.g. body temperature, blood sugar levels reproduction – most living things are able to reproduce at some period in their lives heredity – the passing of genes from parents to offspring (genes are instructions) other properties? development detect and respond to stimuli (senses) excretion based on carbon adaptation energy requirements respiration complex evolution death 1 Biological Themes – ideas that pervade the biological sciences evolution – a population of a species changes over time - occurs by natural selection the flow of energy Sunlight Energy Photosynthetic Organisms Food Energy Other Organisms Eat cooperation e.g. flowers and insects structure determines function e.g. eye versus ear chemical structures have certain structures to be able to perform certain functions Figure 1.6 2 Levels of Organization – small to large subatomic particle – part of an atom atom – basic unit of matter molecule – atoms bonded together macromolecule – large molecule organelle – part of a cell cell – basic unit of life tissue – consists of similar cells combined together to perform a function organ – consists of two or more different tissues combined together to perform a function organ system - combination of organs working together to perform a function organism – individual living thing species – a group of similar, interbreeding organisms population – a group of the same type of organism in an area community – different populations in the same area ecosystem – community (living) and the environment (nonliving) biosphere – earth and atmosphere 3 Figure 1.2 4 Organization of Living Things Living things are organized into groups called taxa (taxon). The three domains of life are Archaea, Bacteria, and Eukarya. Domains are the largest and most inclusive of the taxa. Domain Archaea “unusual” bacteria prokaryotic cells (no nucleus) unicellular some live in extreme environments Domain Bacteria “usual” bacteria prokaryotic cells (no nucleus) unicellular Domain Eukarya eukaryotic cells (nucleus) unicellular and multicellular divided into kingdoms or supergroups Kingdom Protista (????) – amoebae, algae Kingdom Fungi – yeasts, molds, mushrooms Kingdom Plantae - plants Kingdom Animalia - animals Scientific names of organisms consist of a binomial first term - genus second term - specific epithet (species term) italicized or underlined e.g. Homo sapiens (H. sapiens), Escherichia coli (E. coli), Canis familiaris (C. familiaris), Canis lupus (C. lupus) 5 The Scientific Process science a body of knowledge a process stages of the scientific process 1. making an observation and asking a question 2. formulating a hypothesis (an educated guess based on logic and previous knowledge, must be testable) 3. conducting an experiment (controlled study)/making observations to test the hypothesis 4. drawing a conclusion based on results (accept or reject the hypothesis) Example: Observation - People living in an area where the water is contaminated with chemical A develop cancer at a higher frequency than people in other areas. Question - Does chemical A cause cancer? Hypothesis - Chemical A causes cancer in rats. Controlled Experiment – using 200 rats Experimental Group Control Group 100 rats 100 rats Both groups receive the same amount of food, water, light, space, etc. Inject with chemical A Inject with water dissolved in water Outcome Outcome First 98 cancer 1 cancer Second 99 cancer 1 cancer Conclusion – Based on these results, the hypothesis is accepted – Chemical A causes cancer in rats. 6 Theory and Uncertainty hypothesis – educated guess theory – hypothesis that has been tested many times and is almost certain to be true law – absolute truth Ecology – study of how organisms interact with one another and their environment levels of ecological organization population - a group of the same species in an area community - different populations in the same area referred to as the biotic (living) components the place where a community lives is called a habitat (physical environment) referred to as the abiotic (nonliving) components ecosystem – community and environment energy flow - the sun is the ultimate source of energy for all life on earth materials cycle (recycled) – chemicals cycle through the ecosystem human activities – the usual cause of ecosystem disruption/imbalance The Biotic Components producers are autotrophic organisms carry on photosynthesis (able to produce food such as carbohydrate) consumers are heterotrophic organisms directly or indirectly eat producers 7  Figure 45.16 Energy Flows Through Ecosystems trophic levels (feeding levels) based on how organisms obtain energy food chain – linear progression examples: seed mouse owl wolf alga snail fish hawk food web – interconnected food chains the path of energy first trophic level second trophic level third trophic level (producers) (herbivores) (carnivores) 8 Figure 45.18 Figure 45.19 9 Materials Cycle Within Ecosystems (materials are recycled within ecosystems) water (hydrologic) cycle water cycles within an ecosystem in two ways: the environmental water cycle and the organismic water cycle environmental water cycle rain earth’s surface evaporation atmosphere organismic water cycle rain earth’s surface up the roots of plants transpiration (water evaporates out stomata of plants) atmosphere carbon cycle carbon in the atmosphere photosynthetic organisms organic molecules (CO2 – carbon dioxide gas) (food) consumers (aerobic cellular respiration) nitrogen cycle nitrogen in the atmosphere nitrogen fixation ammonium used by plants (N2 – nitrogen gas) (nitrogen-fixing (NH4+) bacteria) denitrification death, excretion, feces consumers (denitrifying bacteria) phosphorus cycle phosphorus in rocks/soil plants consumers urine, feces, decaying tissues (phosphate ions) 10 Populations and Communities a population is all the organisms belonging to the same species within an area at the same time a community consists of the populations of different species that live together and interact in a particular place life history patterns (adaptations) of populations (two types: r-selected populations and K- selected populations) r-selected populations have short life spans produce many young at one time often high mortality rate mature quickly give no parental care examples: dandelions and cockroaches K-selected populations long life spans produce few young at one time usually low mortality rate mature slowly often give extensive parental care examples: whooping cranes, whales, and humans 11 Symbiosis refers to the condition in which two or more dissimilar organisms live together in close association three types of symbiotic relationships commensalism is a symbiotic relationship in which one species benefits while the other neither benefits nor is harmed example: birds using trees as roosting sites mutualism is a symbiotic relationship in which both participating species benefit example: ants and aphids parasitism is a symbiotic relationship in which one species benefits, but the other is harmed (beneficial to the parasite and harmful to the host) tapeworms and humans, viruses and hosts symbiotic relationships can be dynamic 12 Planet Under Stress pollution acid rain (acid precipitation) ozone holes global warming nonreplaceable resources topsoil groundwater biodiversity population growth two models of population growth exponential growth model the number of individuals added each generation increases rapidly produces a roughly J-shaped curve logistic growth model results when limiting environmental factors that oppose growth come into play produces a sigmoidal (S) or S-shaped curve carrying capacity – the maximum number population size that a habitat can support most natural populations exhibit logistic growth 13  human population growth over 7.5 billion people on earth increasing by a little over 79 million people per year the human population is getting larger, but the human population growth rate is declining less-developed countries’ populations growing more rapidly than more-developed countries’ populations many people are gravely concerned about the increased amount of resources that will be needed to support the growth in the human population 14 Figure 44.15 (Note: LDCs = less-developed countries and MDCs = more-developed countries) 15