Biology NYA Lecture 1 PDF

General Biology I 101-NYA-05 Section: 00007/8  Biology NYA Lecture 1 Introduction to Biology August 20th 2024  Socrative Go to https://socrative.com/ Click “student login” Room Name = GRIFFITHS2554 NOT FOR MARKS Just for fun to get...

General Biology I 101-NYA-05 Section: 00007/8  Biology NYA Lecture 1 Introduction to Biology August 20th 2024  Socrative Go to https://socrative.com/ Click “student login” Room Name = GRIFFITHS2554 NOT FOR MARKS Just for fun to get our brains thinking about Biology  Diversity of Life Approximately 2 million species have been identified and named to date. Thousands more are identified each year! Estimates of the total number of species that actually exist range from 8-9 million! ____________ Taxonomy is the branch of biology that names and classifies species into groups of increasing breadth ____________, Domains followed by ____________, Kingdoms are the broadest units of classification  Diversity of Life cont. Species Genus Family Order Class Phylum Kingdom Domain Ursus americanus (American black bear) Ursus Ursidae Carnivora Mammalia Chordata Animalia Eukarya  Three Domain Model Living things are divided into three major groups (Domains): umbrella domain - __________ Bacteria ______________________________ Prokaryotes (no nucleus) - __________ Archaea - __________ Eukarya ______________________________ Eukaryotes (nucleus Stores DNA) ______________________________ ↳ membrane in nuclear  Domain Bacteria cont. Most abundant organisms on earth & > I bacteria (More bacteria in your mouth than there are mammals on the planet!) Present virtually everywhere Some helpful, some harmful Prokaryotic organisms ↳ no nucleus Unicellular organisms E. Coli Have a cell wall composed of __________________ peptidogly can Most taxonomists recognize 12-15 different groups of bacteria  Domain Bacteria cont. Some helpful activities of bacteria: - Decompose organic material - Degrade environmental pollutants - __________________________________________ Digest cellulose in the stomach of cows cannot it ↳ fiber we digest ↳ en plants sugar - Make essential elements such as nitrogen available to other organisms - __________________________________________ Produce Oxygen - Produce vitamin K in the stomach of humans  Domain Bacteria cont. Bacterial diseases: - Attach to cells - Cause tissue damage - Some plant diseases Syphilis - Many human diseases (Syphilis) (Gonorrhea) (Chlamydia) (Typhoid fever) needmedicine to that Typhoid fever  Domain Archaea Prokaryotic cells ↳ no nucleus Unicellular organisms ________________________ Not bacteria None cause disease Have cell walls that lack peptidoglycan I not made of sugar mix (different chemicals) Grouped into three categories based on the environments in which they live or on their specialized metabolic pathways: - ______________________________ extremophiles places (eives in nazy , - ______________________________ Non extreme archaea - ______________________________ Methanogens (only (Hy) live in methane  Domain Archaea cont. ________________________: Methanogens - Obtain their energy by using hydrogen gas to reduce carbon dioxide to methane gas - poisoned by oxygen (strict anaerobes) - live in swamps, marshes, intestines ________________________: Extremophiles - Grow under extreme conditions - Thermophiles (live at 60-80oC and use sulfur in metabolism) - Halophiles (live in very salty environments) - pH tolerant archaea (live in very acidic or very basic environment) - pressure tolerant arachea (need 300 atm to survive = 3000m under ocean) ________________________: Non extreme archaea - grow in similar environment as bacteria  Domain Eukarya Very diverse domain Three characteristics that distinguish eukaryotes from all prokaryotes: 1) ______________________________: Compartmentalization - Discrete compartments within cells - Membrane bound nucleus - Differences in gene expression 2) ______________________________: Multicellularity - Allows to deal with the environment in specialized ways 3) ______________________________: Sexual reproduction - Major characteristic of eukaryotes is sexual reproduction - Allows for genetic diversity Domain Eukarya cont. Three Domain Model  Kingdom - K kF Each Domain is subdivided into Kingdoms In this course we recognize 6 kingdoms Domains Bacteria and Archaea: - Composed of 1 kingdom each - Domain Bacteria = Kingdom Bacteria - Domain Archaea = Kingdom Archaea Eukarya domain is separated into 4 Kingdoms: - __________________ Protista - Plantae (plants) - Fungi - __________________ Animalia (animals us) ,  Kingdom Protista Diverse group of eukaryotic organisms that live in moist or aquatic habitats Most are unicellular or have a unicellular phase in their life cycle Some colonial or multicellular First eukaryotes that evolved 2.1 billion yrs ago Classification is in flux (Some believe there should be 20 kingdoms) (we will stick with 6 for now)  Kingdom Protista cont. Types of protists: - ________________________: Phagotrophs - Animal-like protists - Heterotrophs have to eat to survive - ________________________: Phototrops - Plant-like protists - Autotrophs - ________________________: Osmotrops - Fungus-like protists  Kingdom Protista cont. Amebas (Animal – like): - Have pseudopods (arm-like projections) - Cytoplasm flows - Engulf food - Hold food in vacuole - Digest with enzymes - ______________________________ Contractile vacuole pump to water  Kingdom Plantae Plants Multicellular eukaryotic organisms __________________ Autotrophie (make their own food): - convert sunlight into chemical energy - produce other necessary chemicals from simple substances in the environment have their own cell walls Self sufficient Examples include: ferns, trees, flowers  Kingdom Fungi Includes: mold, mushrooms growing in the forest ________________________: Heterotrophic - Need to obtain energy and chemical building blocks already formed - Obtained by decomposing and absorbing the necessary chemicals Most fungi are decomposers (live on organisms that are no longer alive) Some fungi are ____________ parasites (live on living organism) Some fungi are __________________ mutualists Absorb nutrients from another organism but reciprocate with functions beneficial to their partners in some way)  Kingdom Animalia Contains all of the animals (Eukaryotic, multicellular organisms) Many different kinds of animals Some similar to each other most are not ________________________: Heterotrophic - Need to obtain energy and chemical building blocks already formed - Do so by ingesting and digesting particulate food (plants or other animals)  Classification of Organisms Recall that ____________ taxonomy is the science of classifying living things A classification level is called a ____________ taxon Specific scientific names avoid the confusion caused by common names - Ex.: Stizostedion vitreum is known as - Dore in Quebec - Pickerel in the Prairies - Walleye in other regions By agreement among taxonomists throughout the world, no two organisms can have the same scientific name Taxa (plural of taxon) are based on shared characteristics  The Binomial System Each kind of organism has a unique name The name is made up of 2 words (binomial) in Latin, consisting of the ____________ Genes name (first letter capitalized) followed by the ____________ Species name (lower case), all in italics No other organism in any kingdom has it! Examples: - Homo sapiens = Human Capletter Genes lowercap letter spins - Canis familliaris = Dog all in it alia - Sciurus carolinensis = Grey squirrel  The Binomial System cont. The binomial system was developed by Carl Linnaeus in the 1750s Before Linnaeus most organisms had cumbersome descriptive names that could be up to 15 words long Example: - Apis pubescens, thorace subgriseo, abdomine fusco, pedibus posticis glabris utrinque margine ciliates = European honey bee Binomial system is way more efficient  The Linnaean Hierarchy In the decades following Linnaeus, taxonomists began to group organisms into larger more inclusive categories = ____________________________________ Hierarchal system of classification l - Domain : Eukarya - Kingdom: Animals - Phylum: Chordates - Class: Mammals - Order: Primates - Family: Homidae (Apes) - Genus: Homo (humans) - Species: sapiens You must know the order of the hierarchal system of classification, not specific names  The Linnaean Hierarchy cont. Species Genus Family Order Class Phylum Kingdom Domain Ursus americanus (American black bear) Ursus Ursidae Carnivora Mammalia Chordata Animalia Eukarya  Dichotomous Key Dichotomous (Greek for “cut in two”) keys are used for rapid identification of limited numbers of organisms We still use dichotomous keys today to help identify species A dichotomous key considers only two possibilities at one time, such that a “yes” or a “no” condition exists. (Ex. Wings present; wings not present) The characteristics used to construct a dichotomous key must be observable and kept as simple as possible Choose features that will divide the group of organism approximately in half. Once a group is split into two groups further distinguishing characteristics can be used to separate the groups further, leading finally to identifying the organism