Introduction to Zoology(1).pdf

02/02/2022 SCIENCE – systematiz...

02/02/2022 SCIENCE – systematized body of knowledge that has been tested, proven and verified. BIOLOGY – science of life 2 Forms Of Living Things: Plants and Animals 2 Main Fields Of Biology: BOTANY – science that deals with the study of plants ZOOLOGY – Science That Deals With The Study Of Animals Prepared by: Dept. of Biology, UE - Manila Zoology The study of animals Most zoologists specialize ◦ Subdisciplines (Tables 1.1 and 1.2) 1  02/02/2022 FOUR UNIFYING THEMES OF BIOLOGY 1.All living things share a genetic blueprint – DNA 2.All living things are made up of cells 3.All living things have a common evolutionary forces that will affect change in form, structure, functions and habitat. 4.All living things share the same environment. THEORIES IN THE ORIGIN OF LIFE THEORIES IN THE ORIGIN OF LIFE Creationism - all the different forms of life that occur today on planet earth have been created by God, the almighty. - was purely a religious concept, acceptable only on the basis of faith. It has no scientific basis. Spontaneous generation - assumed that living organisms could arise suddenly and spontaneously from any kind of non-living matter. - was disapproved, as scientists gave definite proof that life comes from pre-existing life. 2  02/02/2022 THEORIES IN THE ORIGIN OF LIFE Pasteur’s Experiment Broth free of Curved Broth is teeming Broth is microorganis neck is with boiled ms for a year removed microorganisms Biogenesis - Living things came from pre-existing living molecules Manifestations of Life / Attributes of Living Things Manifestations of Life / Attributes of Living Things Organisms Sense and Respond to Change Organization Movement / contractility Excitability Organisms sense and respond to change to keep conditions in their internal environment within a range that favors cell survival (homeostasis) - Stimulus types: thermal, impact, acoustic, photic Homeostasis ◦ Set of processes by which an organism keeps its internal conditions within - Response tolerable ranges types: negative, positive Receptor Growth and development ◦ Molecule or structure that responds to a stimulus 3  02/02/2022 Manifestations of Life / Attributes of Living Things Manifestations of Life / Attributes of Living Things Metabolism Organisms Grow, Develop and Reproduce 2 types: a) Anabolism o Forms more complex substances from simpler ones Organisms grow, develop, and reproduce based on information o Concerned with storage of energy encoded in DNA, which they inherit from their parents e.g. assimilation – the food that we eat become a part of the cell b) Catabolism Growth o breaks down complex substances to form simpler ones ◦ Increase in size, volume, and number of cells in multicelled species o concerned with energy expenditure e.g. cellular respiration Development Reproduction ◦ Multistep process by which the first cell of a new individual 2 types: becomes a multicelled adult o Asexual e.g. fission, budding, fragmentation o Sexual Manifestations of Life / Attributes of Living Things Manifestations of Life / Attributes of Living Things Conductivity Organisms Grow, Develop and Reproduce Adaptation ways: - protection : offense, defense , escape and avoidance Reproduction - procurement ◦ Process by which parents produce offspring - reproduction causes of maladjustment Inheritance - physical and chemical defects of the body – heredity ◦ Transmission of DNA from parents to offspring e.g. albinism – absence of pigments color blindness (se – linked traits) - absence of adjustors DNA (Deoxyribonucleic acid) - change is too severe ◦ Molecule that carries hereditary information about traits 4  02/02/2022 Differences Between Living and Non- Living things ATTRIBUTES LIVING THINGS NON-LIVING THINGS Eukaryotes organization Composed of cells Homogeneous movement / locomotion Motile / locomotory Non-motile Plant ◦ Typically a multi-celled, photosynthetic producer irritability Highly irritable Not irritable growth Intersception Accretion (growth is internal (growth is external) Animal through increase in the ◦ Multi-celled consumer that develops through a series number of cells) of embryonic stages and moves about during all or metabolism exhibit Do not exhibit part of the life cycle Differences Between Plants and Animals ATTRIBUTES PLANTS ANIMALS SCIENTIFIC METHOD organization Composed of cells enclosed Composed of cells – set of procedures designed to solve a problem by cell membrane and cell enclosed by cell wall membrane only 1.Observation Movement/ Do not move Highly locomotory - real – authentic - capable of being repeated locomotion because of well- - consistency in cause and effect developed muscles - understandable irritability Low degree Highly irritable due to 2. Identification of problem the presence of sensory 3. Gather relevant data / materials receptors/sense organs 4. Formulation of hypothesis / hypotheses growth Continuous but not Terminal but 5. Experimentation – testing proportionate proportionate independent variable – parameter being tested nutrition autotrophic heterotrophic dependent variable – parameter being measured gas exchange Excrete oxygen utilized by Excrete carbon dioxide 6. Conclusion animals during respiration utilized by plants during photosynthesis 5  02/02/2022 The Scope and Limits of Science LIMITATIONS OF SCIENTIFIC METHOD 1. Pseudoscience Science is a way of looking at the natural world which helps us to 2. Cannot make moral judgment communicate our experiences without bias by focusing only on testable ideas about observable phenomena 3. Cannot make value judgment ◦ Science does not address the supernatural 4. Cannot prove the existence of God Science ◦ The systematc study of nature How Science Works Common Research Practices Researchers make and test potentially falsifiable predictions about how the natural world works 1. Observe some aspect of nature Generally, scientific inquiry involves forming a hypothesis 2. Frame a question about your observation (testable assumption) about an observation then making and testing predictions based on the hypothesis 3. Propose a hypothesis (a testable explanation of the observation) A hypothesis that is not consistent with the results of scientific tests is modified or discarded 6  02/02/2022 Common Research Practices Common Research Practices 4. Make a prediction – a statement based on a hypothesis, 6. Assess the results of the tests (data) to see if they about some condition that should exist if the hypothesis support or disprove the hypothesis is not wrong 7. Conclusions: Report all steps of your work and 5. Test the accuracy of the prediction by experiments or conclusions to the scientific community gathering information (tests may be performed on a model) Making Observations: A Scientific Theory A Field Study Scientific theory ◦ A hypothesis that has not been disproven after many years of rigorous testing ◦ Useful for making predictions about other phenomena 7  02/02/2022 Laws of Nature Law of nature ◦ Generalization that describes a consistent and universal natural phenomenon for which we do not yet have a complete scientific information ◦ Example: gravity The Power of Experiments The Power of Experiments Natural processes are often influenced by many Experiments simplify interpretations of complex biological interacting variables systems by focusing on the effect of one variable at a time Variable Experiment ◦ A characteristic or event that differs among individuals ◦ A test to support or falsify a prediction 8  02/02/2022 Experimental and Control Groups Potato Chips and Stomach aches Experimental group ◦ A group of objects or individuals that display or are exposed to a variable under investigation Control group ◦ A group of objects or individuals that is identical to an experimental group except for one variable Hypothesis Olestra® causes intestinal cramps. Potato Chips and Stomach aches Prediction People who eat potato chips made with Olestra will be more Example: Butterflies and Birds likely to get intestinal cramps than those who eat potato chips made without Olestra Question ◦ Why does a peacock butterfly flick its wings? Experiment Control Group Experimental Group Eats regular Eats Olestra potato chips potato chips Two hypotheses Results 93 of 529 people 89 of 563 people get ◦ Exposing wing spots scares off predators get cramps later cramps later ◦ Wing sounds scare off predators (17.6%) (15.8%) Conclusion Two predictions Percentages are about equal. People who eat potato chips ◦ Individuals without spots are eaten more often made with Olestra are just as likely to get intestinal cramps ◦ Individuals without sounds are eaten more often as those who eat potato chips made without Olestra. These results do not support the hypothesis. 9  02/02/2022 Experiments and Results Peacock Butterfly Defenses Four groups of butterflies were exposed to predators (birds) ◦ Butterflies without spots ◦ Butterflies without sounds ◦ Butterflies without spots or sounds ◦ Control group Test results support both original hypotheses Results: Peacock Butterfly Experiment References: Biology Today and Tomorrow by Starr, Evers and Starr Zoology by Stephen A. Miller and John P. Harley 10