Biology 1052 PDF - Past Paper

Biology 1052 Week 1: Scientific Method & Characteristics of Life Scientific Method The Scientific Study of Life Scientific inquiry follows the SCIENTIFIC METHOD: 1. Observation 2. Question 3. Hypothesis 4. Experiment 5. Analysis 6. Conclusion Inductive Reasoning: Creative thinking combines isolated facts into a cohesive whole. Used in making a hypothesis. Hypotheses need to be tested. SPECIFIC OBSERVATION → PATTERN RECOGNITION → GENERAL CONCLUSION 1. Observation: - A low-cost airline flight is delayed. 2. Observe a Pattern: - Another 20 flights from low-cost airlines are delayed. 3. Develop a Theory or General Conclusion: - Low cost airlines always have delays. Deductive Reasoning: Considers possible relationships of different factors. Used in making a prediction. Predictions are required for experiments. EXISTING THEORY → FORMULATE HYPOTHESIS → COLLECT DATA → ANALYZE DATA → DO/DON'T REJECT HYPOTHESIS 1. Start with an Existing Theory: - Low cost airlines always have delays. 2. Formulate a Falsifiable Hypothesis Based on Existing Theory: - If passengers fly with a low cost airline, then they will always experience delays. 3. Collect Data to Test the Hypothesis: - Collect data of low-cost airlines. 4. Analyze and Test the Hypothesis: - 5 out of 100 flights of low-cost airlines are not delayed. 5. Decide Whether You Can Reject or Support the Hypothesis: - 5 out of 100 flights of low-cost airlines are not delayed = reject hypothesis. Experiment: INDEPENDENT VARIABLE: what is being tested? - EX: attendance DEPENDENT VARIABLE: what is changing as a result of the experimental variable? - EX: grades CONTROL VARIABLE: ensures that the change (EX: higher grades) is due to the experimental variable (EX: attendance) and not some other factor (EX: hours of study). Data: Results of experiments are prepared. - Tables, graphs, charts Results are analyzed. - Statistical analysis → was the change likely due to chance? Or other variables? Results are shared with the scientific community. The Process of Science: Scientific Theory: Hypotheses that are related and well-supported (through repeated experimentation) form SCIENTIFIC THEORIES. In science, a theory is supported by a broad range of observations, experiments, and data. - Examples: cell theory, homeostasis theory, evolution theory. The theory of ________ is the unifying concept of biology Characteristics of Life The Characteristics of Life: Life exists almost everywhere on the planet Earth. Earth possesses a great variety of diverse life forms. - There are estimated to be 8.7 million different species (not including bacteria) & some sources estimate 2 billion species of bacteria. All living things have certain ______________ in common. Characteristics of Life: 1. Are ORGANIZED - Living things are organized into a hierarchy of levels. 2. Acquire MATERIALS and ENERGY - Living things need an outside source of materials and energy. - Energy = capacity to do work → maintain homeostatic 3. Reproduce - Reproduction ensures survival of the species. - Genetic information is passed from one generation to the next. 4. Respond to STIMULI - Sense organs: eyes → light, ears → sound 5. Are homeostatic - The maintenance of internal stability. - EX: shivering in winter, sweating in summer 6. Grow and DEVELOP - Growth = number and size - Develop = cells develop into tissue 7. Have the capacity to ADAPT - Changes overtime in response to the environment. - Adaptations: features that increase survival. Classification of Organisms Three Domain System of Classification: The Classification of Organisms (Science of Organizing the Diversity of Life): Living organisms are assigned to groups based on their similarities. SYSTEMATICS is the study of the evolutionary relationships among organisms. - Research performed by systematists may result in changes to the current classification system. - Identify, name, classify, discover, understand the evolutionary connection between living thing.s - Broad field of biology that studies the diversifications of species. - Governs the evolutionary history and phylogenetic relationship in addition to taxonomy. - Taxonomy + Phylogeny = Systematics TAXONOMY is the discipline of identifying and grouping organisms. - Discipline of classifying organisms into taxa. - Governs the practices of naming, describing, identifying and specimen preservation. - Classification + Nomenclature = Taxonomy Categories of Classification: MOST INCLUSIVE 1. Domain (Domain Eukarya): - Cells with nuclei 2. Kingdom (Kingdom Animalia): - Multicellular, motile, ingestion of food 3. Phylum (Phylum Chordata): - Dorsal supporting rod and nerve cord 4. Class (Class Mammalia): - Hair, mammary glands 5. Order (Order Primates): - Adapted to climb trees 6. Family (Family Hominidae) - Adapted to walk erect 7. Genus (Genus Homo) - Large brain, tool use 8. Species (Species Sapiens): - Body characteristics similar to modern humans LEAST INCLUSIVE ★ Drooling King Philip Came Over For Green Soup Week 2: Study of Life & Evolution of Life Charles Darwin (Father of Evolution): Initially believed that species had remained unchanged since the time of creation. During his 5-year voyage, he collected and recorded the geological and biological diversity. While travelling to the Galapagos Islands, Darwin observed differences in the size and shape of beaks between finches on different islands. Theory of Evolution: EVOLUTION: any evolved trait that helps an organism be more suited to its environment. Natural Selection: Individual organisms in a species exhibit variation that is BLANK. - Can be passed from one generation to the next. Organisms compete for available resources. - Individuals in a population produce more offspring than the environment can support Some individuals in a population have favorable traits that enable them to better compete for limited resources (survival of the fittest) - Will have greater reproductive success. Organisms become adapted to environmental conditions, as traits that are favorable will increase in a population due to increased reproductive success. - Descent with modification Theory of Evolution: One scientist that influenced Darwin was a predecessor named Jean-Baptiste de Lamarck. Lamarck developed the theory of inheritance of acquired characteristics. - The environment can bring about an inherited change. Lamarck Darwin Inheritance of acquired characteristics Evolution by Natural Selection The example used by Lamarck was Darwin’s theory would predict that that the long neck of the giraffe giraffe populations would include developed over time because giraffes individual giraffes with longer necks stretched their necks to reach food in than others. trees. Individuals with longer necks could They then passed gradually longer reach more leaves, acquire more necks to their offspring. energy, and potentially produce more offspring that inherited the long neck trait. Over time, the trait would be more common in a population (adaptation to the environment). Think, Pair, Share: What are some examples of adaptations that have evolved in living organisms? - The shape of a bird’s beak - The color of a mammal’s fur - The thickness or thinness of the fur - That shape of the ears or nose ★ Help for survival Evidence of Evolution - Fossils: Some fossils serve as transitional links between groups. - They have some traits like their ancestors and others like their descendants. Evidence of Evolution - Biogeographical: CONTINENTAL DRIFT: the position of the continents and oceans has shifted throughout Earth’s history. Australia has many distinct species because it has been geographically isolated for about 50 million years. Evidence of Evolution - Anatomical: HOMOLOGOUS STRUCTURE: anatomically similar because they are inherited from a common ancestor. - Forelimbs of different species share same general structure but different function ANALOGOUS STRUCTURE: NOT anatomically similar; not from a common ancestor. - Similar function because of similar environments. Evidence of Evolution - Biochemical: Humans and chimpanzees have a high degree of similarity in DNA sequences. - 97% related Terminology: GENE: a segment of DNA information for one specific trait/protein. ALLELES: variation in a gene. Processes of Evolution: EVOLUTION is the change in traits that are heritable. - Evolutionary change occurs in populations over many generations. We now understand evolution in terms of genetic inheritance, as genes interact with the environment. - A gene is a segment of DNA that codes for a trait. - Traits are passed from one generation to the next via alleles (alternate forms of a gene). Mutations: MUTATIONS are changes in the DNA. - Change in segment of chromosomes - Variations in alleles - Sequences of DNA - Environmental factors The only source of new inheritable variation in a population. Mutations are random events. - A mutation does not arise because the organism “needs” one. Some are beneficial (provide a survival advantage), and some are harmful.. New mutations can cause variation of genes in a population. - Nature has more options. Genetic Drift: GENETIC DRIFT refers to a change in small population’s allele frequency due to a random chance. - Change of variation → narrows the variation It’s not based on fitness but pure luck of any natural disaster or random event. NATURAL DISASTERS: hurricane, volcano, tsunami, earthquake, fire etc. RANDOM EVENTS: stepped on, ran over, picked up etc. FOUNDERS EFFECT: part of the original population colonized a new area. BOTTLENECK EFFECT: a natural disaster happens leaving few survivors from an original population. Gene Flow: GENE FLOW is the movement of alleles between populations. - Increase in the variation. - Individuals or their gametes migrate from one population to another and breed in the new population. Gene flow mixes genetic diversity. - More diversity. Natural Selection: Some individuals in a population have favorable traits that enable them to better compete and survive (survival of the fittest). Over the years, nature’s actions select populations with favorable traits that are passed onto the future generation/descendents. Non-random Mating: NON-RANDOM MATING occurs when individuals are selective about choosing a mate with a preferred trait. - Less diversity. Random mating is never observed in natural populations, because most sexually reproducing organisms select mates based on some trait. ARTIFICIAL SELECTION is a human-controlled breeding to increase the frequency of desired traits. Microevolution: Within species variation. - Same species EX: Different breeds of dogs, due to artificial selection. Macroevolution: The process of evolution on a large scale. - Results in the formation of a new species. SPECIATION: when one species gives rise to two species - Recall: species – a group of similar, interbreeding organisms. - They are reproductively isolated from other species. Ex. New species of salamanders, in California, evolved from a Northern species Populations are reproductively isolated by the geographical barrier. Week 3: Cell Structure and Function Cells Cell: The CELL is the structural and functional unit of an organism, the smallest structure capable of performing all the functions necessary for life. All cells have 3 things in common: 1. Cell/Plasma Membrane 2. Cytoplasm 3. Genetic Material (DNA) Cell Theory: Cells are the basic units of life. All living organisms are composed of one or more cells. All cells come only from previously existing cells. Types of Cells: PROKARYOTIC CELLS lack membrane enclosed structures. EUKARYOTIC CELLS possess membrane enclosed structures. Plasma Membrane and Cytoplasm: All cells are surrounded by a PLASMA MEMBRANE. The material inside of a cell is the CYTOPLASM. The plasma membrane regulates what enters and exits a cell. Head → polar Tail → nonpolar → hydrophobic Intro → inside Inter = between Learning Check: Which of the following organelles is the principal and distinguishing feature of the eukaryotic cell? a) Mitochondria b) Chloroplast c) Nucleus d) Ribosomes e) Lysosomes Surface Area/Volume Ratio Not all cells are the same size. The fact that cells are so small is a great advantage for multicellular organisms. The amount of surface area affects the ability to get materials in and out of a cell. As cells increase in volume, the proportionate amount of surface area decreases. All three have the same volume, but the group on the right has four times the surface area. Prokaryotes: Structurally simple. Metabolically diverse. Adapted to most types of environments. Felagella = plural Pili = plural Pilus = singular Plasmid = small circular DNA Protein factory of cells. Not linear. Eukaryotes (Animal and Plant): Are structurally complex. Have a nucleus. Possess membrane-bound organelles. Examples are animals, plants, fungi and protists. Nucleus: Stores DNA. Nucleolus. Nuclear Envelope. - Double membrane, continuous with endoplasmic reticulum, disappears during cell division. - Nuclear pores → bidirectional transport of proteins and ribosomal subunits Ribosomes: Site of protein synthesis. Two subunits (large and small). - Subunits consist of rRNA and protein molecules. Polyribosomes. - Several ribosomes with a single mRNA molecule. Endoplasmic Reticulum: Consists of membranous channels and saccules (flattened vesicles). Rough ER. - Processing and modification of proteins. - 3D protein functional Smooth ER. - Synthesizes phospholipids. - Produces lipids. Golgi Apparatus: Post office of the cell. Collects, sorts, packages, and distributes materials such as proteins and lipids. Proteins made in Rough ER have tags that serve as “zip codes” to direct Golgi apparatus where to send them. Lysosomes: Contain hydrolytic digestive enzymes that break down unwanted, foreign substances or worn - out parts of cells. Considered the garbage disposal of the cell. Only in plant cells. Vacuoles: Membranous sacs that store substances. EX: water, pigments, toxins Only in plant cells. Peroxisomes: Membrane bound vesicles containing enzymes. The enzymes break down molecules (fatty acids) and as a result produce hydrogen peroxide (H2O2). H2O2 is then broken down to water and oxygen. Peroxisomes found in liver cells In both plant and animal cells. Endomembrane System: Nuclear envelope Endoplasmic reticulum Golgi apparatus Vesicles Learning Check: The ______ function(s) in the packaging, storage, and distribution of molecules produced by the ER. a) Golgi apparatus b) Lysosome c) Nucleus d) Mitochondria e) Centrioles Energy-Related Organelles: Chloroplasts use solar energy to synthesize carbohydrates. Carbohydrates are broken down in Mitochondria. Chloroplasts: Site of photosynthesis. Structure: - Double-membrane - Stroma - Grana ↳ Thylakoids Chloroplasts contain: - Their own DNA - Ribosomes - Enzymes Mitochondria: Found in all eukaryotic cells. Site of cellular respiration. Structure: - Double-membrane - Matrix - Cristae Mitochondria contain… - Their own DNA - Ribosomes - Enzymes Cytoskeleton: Maintains cell shape. Assists in movement of cell and organelles. Assemble and disassemble as needed. Three types of macromolecular fibers: 1. Actin Filaments 2. Intermediate Filaments 3. Microtubules Actin Filaments: Smallest among all three cytoskeletal fibers. Are long, extremely thin (7nm), flexible fibers. 2 filaments wrapped around each other. Mechanical support. Determines cell shape. Allows movement of the cell surface: - Enabling cells to migrate. - Engulf particles. Play a role in animal cell division. Anchored to the plasma membrane. Allows intestinal microvilli to expand and contract. Play a role in animal cell division, cell movement.

Biology 1052 PDF - Past Paper

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