General Biology 2 Past Paper PDF - Qtr3 Week 2 - Pavia National High School

Republic of the Philippines Department of Education Region VI- Western Visayas PAVIA NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT...

Republic of the Philippines Department of Education Region VI- Western Visayas PAVIA NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT GENERAL BIOLOGY 2 Name: ______________________Grade/Strand & Section: _______________ Date: _________ Change Over Time (Quarter 3, Week 2) Learning Competencies with Code  Describe general features of the history of life on Earth, including generally accepted dates and sequence of the geologic time scale and characteristics of major groups of organisms present during these time periods (STEM_BIO11/12-IIIc-g-8)  Explain the mechanisms that produce change in populations from generation to generation (e.g. artificial selection, natural selection, genetic drift, mutation, and recombination) (STEM_BIO11/12-IIIc-g-9). Background Information for the Learners Evolution  a biological phenomenon that involves changes in a species over time  all the changes that have transformed life on Earth from its earliest beginnings to the diversity that characterizes it today Geologic Time Scale Figure 1. Geologic Time Scale 1  Geologic Time Scale  tabular presentation of the history of life based on geologists’ study of rocks and the fossils they contain  all the pieces of information about Earth are arranged chronologically from the oldest (bottom table) to the most recent (top table) Mechanisms of Evolution 1. Natural Selection Figure 2. The Darwin’s Finches diagram illustrates the way the finch has adapted to take advantage of feeding in different ecological niches.  Some individuals with certain traits in a population have a higher survival and reproductive rate than others and pass on these inheritable genetic features to their offspring.  Evolution acts through natural selection whereby reproductive and genetic qualities that prove advantageous to survival prevail into future generations. 2. Genetic Drift Figure 3. Population Bottleneck 2  Figure 4. Founder Effect  stochastic process, a random event that happens by chance in nature that influences or changes allele frequency within a population as a result of sampling error from generation to generation  The population bottleneck and a founder effect are two examples of random drift that can have significant effects in small populations. o Bottleneck effect occurs when there is a sudden sharp decline in a population’s size typically due to environmental factors that can decimate the number of individuals in the population, predation or habitat destruction. o Founder effect is the loss of genetic variation that occurs when a new population is established by a small number of individuals that are cleaved from a larger population. 3. Mutation Figure 5. Mutation  change in the DNA sequence within a gene or chromosome of a living organism  source of genetic variation and serve as a raw material for evolution to act 4. Gene Flow ( Gene Migration ) Figure 6. Gene Flow 3   transfer of genes from the gene pool of one population to another  may change the frequency and/or the range of alleles in the populations due to the migration of individuals or gametes that can reproduce in a different population Figure 7. Mechanisms of Evolution 5. Artificial Selection  selective breeding of organisms to produce domesticated animals with more desirable traits;  selective breeding to test for genetic variation and covariation in a population. 6. Recombination  process by which pieces of DNA are broken and recombined to produce new combinations of alleles.  creates genetic diversity at the level of genes that reflects differences in the DNA sequences of different organisms  occurs during meiosis Directions / Instructions Read and study the different activities. Write your answer on a separate sheet of paper. Exercises / Activities Activity 1. Interpreting Geologic Time Scale Analyze the Geologic Time Scale found on page 1 and answer the following questions: 1. What was happening to the continents during the Mesozoic era? 2. What creatures are dominant during the Cenozoic era? 3. What was the most abundant creature during the Mesozoic era? 4. What was the most abundant creature during the Paleozoic era? 5. What era is characterized by the first appearance of cyanobacteria? 6. What period is characterized by the extinction of the dinosaurs? 4  7. What do you think had caused the mass extinction of the species? 8. What happened after each mass extinction? Activity 2. Tracing Evolution of an Organism 1. Select one domesticated plant or animal. 2. Make a pictogram or poster showing changes in the traits (evolution) of your chosen domesticated plant or animal. Include in your poster the traits of the organism as it evolves. 3. Explain how did the domesticated plant or animal come up with the new trait. (Refer to the mechanisms of evolution.) 4. Put your output in a long bond paper and pass it to our google classroom. Access the rubric for scoring in the google classroom. Reflections Complete the statements below. I understand ________________________________________________________ ________________________________________________________ I don’t understand _______________________________________________________ _______________________________________________________ I need more information about ________________________________________________________ ________________________________________________________ Answer Key Activity 1 1. Drifting apart from each other 2. Mammals, humans, grasses 3. Reptiles 4. Trilobites 5. Precambrian 6. Cretaceous 7. Changes in environmental conditions, volcanic eruptions, meteorites, etc. brought about mass extinction 8. New sets of organisms appeared and become dominant Activity 2 Pictogram may vary. References: Campbell, N., Reece, J., & Mitchell, L. (1999). Biology. California. Addison Wesley Longman,Inc. Rabago, L., Joaquin, C., & LagunzadC. ( 2003). Functional Biology. Philippines. Vibal Publishing House, Inc. https://www.nature.com/scitable/definition/artificial-selection- 230/#:~:text=Selective%20breeding%20of%20organisms%20to,Compare%20to%20natural %20selection. Note. Please practice personal hygiene at all times. Prepared by: SIENA G. CAJILIG, PhD Master Teacher II 5