General Biology 1, Lecture 2 Notes
General Biology 1, Lecture 2 Notes 101-NYA-05
Popular in General Biology 1
verified elite notetaker
Popular in Biology
This 7 page Class Notes was uploaded by CatLover44 on Monday September 5, 2016. The Class Notes belongs to 101-NYA-05 at Dawson Community College taught by Virginia Hock in Fall 2016. Since its upload, it has received 12 views. For similar materials see General Biology 1 in Biology at Dawson Community College.
Reviews for General Biology 1, Lecture 2 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/05/16
General Biology 1 Course Number : 101-NYA-05 Date: Monday, August 29, 2016 Professor: Dr. Virginia Hock Topics Covered : properties of life, the cell’s blueprint, hierarchy of biological organization, unity and diversity (evolution and natural selection), taxonomy, and ecosystem dynamics. Important Concepts in Biology (Summary): 1. Properties of Life; 2. Transmission of Heritable Traits Through DNA; 3. Classification of Organisms; 4. Evolution and Natural Selection; 5. Taxonomy: the Science of Naming Organ isms; 6. Ecosystem Dynamics Concept no. 1: Properties of Life (Review) - Properties of life are exclusive to organisms . Only living things that are made of cells (either multi - cellular or single -celled) have these characteristics: Organisms : 1) are made of cells and/or biomolecules ; 2) can metabolize energy; 3) respond to changes in their environments (to evade dangerous situations); 4) regulate themselves to maintain homeostasis (evident at the cellular level); 5) grow and develop their biological traits; 6) reproduce either sexually (humans) or asexually (bacteria); 7) may evolve (as a population, not as individuals). Concept no. 2 : DNA is the Cell’s Blueprint According to cell theory, all cells: - are the smallest unit of life; - constitute all life forms ; - come from pre -existing cells . - DNA is essential to life because it oversees the cell’s activities , such as its metabolism . It contains four different nucleotides , which are abbreviated as A, T, C, G . - Nucleotides are essentially chemical building blocks. You can think of them as a four -letter alphabet of inheritance . Specific arrangements of the four nucleotides encode information into genes. - Our genes determine traits like hair colour and eye colour. - RNA (ribonucleic acid) helps DNA to complete its tasks . For example, when our bodies produce melanin, RNA is activated. - RNA copies DNA into a form that it can use : RNA is a messenger , meaning it can leave the cell’s nucleus. DNA can't leave the cell’s nucleus . Evidently different cellular processes take place in different compartments of the cell. - DNA is made up of genes, which are the units of inheritance that transmit genetic information from parents to their offspring. - Genes are made of different lengths and sequences of the 4 nucleotides. Concept no. 3: Hierarchy of Biological Organization Hierarchical Organization of Organisms: 1) Molecules; 2) Organelles; 3) Tissues; 4) Organs; 5) Organ systems; 6) Organisms; 7) Populations; 8) Communities; 9) Ecosystems; 10) Biosphere. Analyzing the Biologically -organized Organisms 1) Molecules : biomolecules (very large molecules ) are particularly important in biology . For example, when enough hydrocarbons are strung together they form sugars (C6H12O6) or fats (C3H8O3), which both have relatively comple x Lewis structures. Sugars and fats, or phospholipids, are essential to the well being of a cell because their membranes are composed of these biomolecules . 2) Organelles : organelles are a cell’s organs. They carry out specialized tasks for a cell. Some examples of organelles are the nucleus, the Golgi, and the mitochondrion . - the nucleus is a cell's control centre. This is where DNA is contained. - the Golgi takes simple molecules, and turns them into more complicated ones. It then takes those big molecules, keeps them inside vesicles, and and stores them or sends them out of the cell. You can think of the Golgi as a packaging and transport centre. - the mitochondrion produces a cell's energy. 3) Cells: the smallest unit of life, made up of many differe nt molecules and organelles. All cells have membranes , and contain genetic information (DNA) , internal mass (cytoplasm) , and ribosomes that allow for protein synthesis. 4) Tissues: groups of a particular type of cell that perform the same function. Bones, m uscles, and skin are made of tissues. 5) Organs: groups of tissues that all serve the same purpose . 6) Organ systems: groups of organs that perform a specific function. 7) Organisms : individual living things that vary in comp lexity and size. For example, prokaryotic cells are much smaller and simpler in terms of their biological makeup than eukary otic cells. Another example is the comparison of a single celled bacteria to a mammal that's composed of trillions of cells and several organ systems. All of these are examples of living things, but some are larger and more complicated than others. 8) Populations : group of the same kind of organism living together in one place . For example, the population of cats in a given neighbourhood. 9) Communities : groups of different types of organisms that live together and interact with/ depend on each other. 10) Ecosystems: the community of organisms in a particular area and their interactions with their surroundings. Ecosystems include non -living things, like sources of energy. 11) Biosphere: all of Earth’s ecosystems . The biosphere contains all the parts of our planet inhabited by organisms. Concept no. 4: Evolution Explains Biological Unity and Diversity - Organisms that don't appear to be similar actually share common traits , particularly at the lower levels of biological organization. - For example, a bat’s wings have the same bones, joints, nerves, and blood vessels fo und in the human arm. - The universal gene tic language of DNA are what make eukaryotes and prokaryotes similar to each other. - If you analyze eukaryotes of different organisms closely enough, you will see similarities in their cell structure. - According to Charles Darwin, species demonstrate descent with modi fication from common ancestors: unity within members of a species that inherited traits from the same ancestors, and diversity in the genetic modifications that occurred as they deviated from those ancestors. - The reasoning behind descent with modification is natural selection . Natural selection occurs when species with traits that aren't beneficial to their survival are eliminated , and only the members of that species that are better adapted to their environment can survive and reproduce. This phenomenon results in a species that is more likely to survive in their specific environment. - Natural selection occurs in several steps : 1) The organisms in populations are not exactly the same as each other . They have varying biological traits that can benefit them, endanger them, or have no impact on their survival. 2) Since organisms reproduce, resources that are necessary for survival are scarce . This forces organisms to compete in order to survive . 3) Individuals that are better adapted to their environment are more likely to get the resources they need to survive , and they will reprodu ce. This step is where natural selection occurs . 4) Surviving members of the population reproduce, and pass on their adaptive traits to their offspring. Note: adaptive traits can change over time , causing populations to evolve over time . The environment selects individuals with beneficial traits, and allows them to reproduce. - By examining an organism’s evolutionary history, we can understand why they're made of certain biomolecules, the purposes of their cellular activities, the reasons for their structure s, and why they behave in the ways they do. o For example: birds have aerodynamic wings that reduce drag so they can fly faster and with more ease; thin and flat leaves in plants maximize the amou nt of light they absorb so the process of photosynthesis is optimi zed; elongated structures in cells allow for quick long-distance communication ; certain insects have intricate patterns so they can easily hide from predators . Concept no. 5: Classification - Biologists organize organisms according to their similarities - Taxonomy is the science of naming and classifying organisms - Certain rules must be followed when naming organisms . When naming a species, we must consider its genus and its subspecies. For example, the name of an insect of the species Scaptia beyonceae is composed of two parts. The first word, Scaptia, is called the genus and the first letter of the genus is always capitalized . The second word, beyonceae, is in lowercase, but both words are in italics . - Another example is Sylvilagus palustris hefneri: the first word is the genus, the second is the species, and the last word is the subspecies. All the words are in italics . - Taxonomic classification is hierarchical , and is comprised of several diffe rent categories that range from general to specific. - Remembering this mnemonic may simplify the task of remembering these categorizations: Dumb Kings Play Chess On Fine Grain Sand. - The table below is meant to help you to visualize the different taxonomic groups. Mnemonic Vs. Taxonomic Classification Mnemonic Taxonomic Classification Dumb Domain Kings Kingdom Play Phylum Chess Class On Order Fine Family Grain Group Sand Species (subspecies) - Domains o Three domains are mentioned in this lecture: Domain Eubacteria, Domain Archaebacteria, and Domain Eukar ya. - Kingdoms o Four kingdoms were mentioned in this lecture: Kingdom Fungi, Kingdom Animalia, and Kingdom Protista , which is under construction because it's composed of any organisms that don't quite fit into the Animalia, Plantae, or Fungi kingdoms . § There are als o supergroups, which are shown in the figure below: - A binomial system was developed by Linnaeus in the 1700’s which assigned organisms with Latin names. When using this binomial system, we refer to organisms by their genus and their species. For example, Kingdom Animalia contains all animals. Some animals share similar traits while others do not. This system was put into place to help Biologists avoid confusion; everyone knows which species is being discussed without any ambiguity. - Consider how the jaguar would be classified according to the taxonomic hierarchy ( Dumb Kings Play Chess On Fine Grain Sand) o Jaguar: § Domain: Eukarya § Kingdom: Animalia § Phylum: Chordata § Class: Mammalia § Order: Carnivora § Family: Felidae § Genus: Panthera § Species: onca Concept 6: Ecosystem Dynamics - Organisms interact with other organisms and the non -living components of their environment . - In most ecosystems, nutrients are re cycled—once they are used by consumers, they're decomposed so they can be used agai n. - Nutrients pass through biotic and abiotic forms. o Biotic: living components of an ecosystem o Abiotic: non-living components of an ecosystem - Energy enters an ecosystem as light , and leaves as thermal energy (heat) - There are three types of organisms : 1) Producers: photosynthetic plants. Producers convert light energy into chemical energy from raw materials. They can also be called autotrophs, which are self-feeding organisms. Plants and algae are examples of autotrophs because they use sunlight as their main source of energy. 2) Consumers: feed on producers and other consumers . They are unable to produce heir own energy. Consumers are heterotrophs , which means they obtain energy by breaking down the food that's provided by producers. Herbivores , carnivores, and omnivores are examples of consumers. 3) Decompose rs: are also heterotrophs . They obtain their energy by breaking down dead organic matter. They play a very important role in the recycling of nutrients: nutrient recycling wouldn't be possible with out decomposers . Bacteria and fungi are decomposers. They decompose producers and consumers after they die.
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'