Integrated Science 2 Past Paper (Philippines) PDF

LEARNING GUIDE Subject Code IS2 Integrated Science 2 Module Code 1.0 What is Life? Lesson Code 1.3.1 Viruses: Living or Nonliving? Time Limit 30 minutes Components Tasks...

LEARNING GUIDE Subject Code IS2 Integrated Science 2 Module Code 1.0 What is Life? Lesson Code 1.3.1 Viruses: Living or Nonliving? Time Limit 30 minutes Components Tasks TA​a ATA​b Target After completing this module, you are expected to: 2 min C1.A.c.1 Discuss how viruses can be viewed as either living or nonliving things C1.A.c.2 Describe the noncellular structure of viruses and their ability to reproduce if within a host Hook You are now reading this module at the comfort of your 3 min home amidst a global pandemic. We are advised to stay at home to help stop the transmission of the infectious disease. CoViD-19 stands for Coronavirus Disease of 2019 which is caused by the SARS-CoV-2 virus. But what are viruses? Let’s learn it. The picture below is what a coronavirus looks like under scanning electron microscope. Figure 1. Wuhan coronavirus (circular-shaped) near an infected cell Source: University of California San Francisco. Retrieved from https://www.ucsf.edu/news/2020/01/416511/mysterious-coron avirus-spreads-infectious-disease-expert-explains-what-you COVID-19 is a highly transmittable disease caused by the virus – SARS-CoV-2 which started in Wuhan, China and spread around the world, making it a pandemic. PHILIPPINE SCIENCE HIGH SCHOOL SYSTEM Integrated Science 2 Page ​1​ of ​8  FORMATIVE ASSESSMENT 1 o Based on the statement above, what characteristics of life does SARS-CoV-2 possess? ______________________________________________ ______________________________________________ ______________________________________________ o Since viruses show some characteristics that living organisms possess, can they be considered living or nonliving? ______________________________________________ ______________________________________________ Ignite Are viruses dead or alive? Let us compare them to the 20 min characteristics of life to determine if something has life. o Living things are made up of cells. o Living things reproduce (Reproduction). o Living things grow and develop (Growth and Development) o Living things require energy through metabolism. o Living things adapt to their environment through evolution (Adaptation and Evolution). o Living things can move (Movement). o Living things maintain homeostasis. Living things are made up of cells. Viruses are acellular which means they are not composed of cells. A ​virion ​(complete single particle of virus) is made up of two main parts: ​capsid ​and ​nucleic acid (genetic material)​. Capsid ​is a protein shell or capsule that encloses and protects the ​genetic material​ of a virus that can have either DNA or RNA, but never both. A virus does not contain both DNA and RNA in a capsid. There are virus strains (e.g. SARS-CoV-2) that do have an ​envelope​, an extra membrane of lipid bilayer. Viruses do not have organelles, nuclei, or cytoplasm like cells do. Viruses are categorized based on general composition: naked/nonenveloped viruses​ and ​enveloped viruses​. Naked viruses are those that have the genetic material and capsid only, while enveloped viruses are those that have the genetic material, capsid, and a lipid layer (Gelderblom, 1996). PHILIPPINE SCIENCE HIGH SCHOOL SYSTEM Integrated Science 2 Page ​2​ of ​8  Figure 3. A nonenveloped virus - e.g. bacteriophage – (Kaiser, 2019). Bacteriophage is a type of virus that infects and destroys the bacterial cell. In fact, the word “bacteriophage” literally means “bacteria eater.” Are viruses made up of cells? ​ ​☐ ​Yes ​☐​No Living things reproduce. Viruses definitely multiply. Our body’s immune system is designed to defend the body from a virion, but a large number of virions produced in a short period of time could harm our cells. Since viruses do not have organelles, and ribosomes, they are incapable to replicate their genes to produce new virions. That’s why they live inside a cell and use the cell as a host to replicate their genetic information, create new capsids, and assemble everything together. Viruses depend on the host cells that they infect to reproduce. Bacteriophages are viruses that infect bacteria. Bacteriophages may carry out a ​lytic cycle, a ​ ​lysogenic PHILIPPINE SCIENCE HIGH SCHOOL SYSTEM Integrated Science 2 Page ​3​ of ​8  cycle ​or both. Lytic cycle is also referred to as virulent infection because the virus kills the host cell. Lysogenic cycle is non-virulent infection because the virus does not destroy or kill the host cell but uses it as a shelter where it exists in a dormant/inactive state. In the ​lytic cycle​, the virus injects its genetic material into the host cell, breaking down the genetic material of the host that allows the virus to take control of the cell. The virus uses the host cell to synthesize proteins needed to create new virions. During this process, the host cell weakens and eventually bursts, releasing new virions and going on to infect other cells. In the ​lysogenic cycle​,​ ​the virus injects and integrates its genetic material into the host’s genetic material. As the cell divides, the genetic material of the virus is replicated along with the host’s genetic material. The virus remains inactive until the host cell deteriorates. As the virus becomes active, the cell bursts, releasing a new virion. Figure 4. A bacteriophage undergoing a lytic cycle (Steward, 2018). PHILIPPINE SCIENCE HIGH SCHOOL SYSTEM Integrated Science 2 Page ​4​ of ​8  Figure 5. A bacteriophage undergoing a lysogenic cycle (Steward, 2018). Can viruses reproduce on their own? ​☐​Yes ​☐​No Living things grow and develop. Once a virus injects its genetic material to a host cell, it would eventually create and release virions in their fully-formed state. These virions do not increase in size nor in complexity. Do viruses grow and develop? ​ ​☐ ​Yes ​ ​No ☐ Living things use and require energy through metabolism. Viruses require a lot of energy to create new virions, from building genetic material and capsids together. However, the energy they utilized comes from the host cell because viruses cannot metabolize. Do viruses get energy through metabolism? ☐​ Yes ​☐ ​ No Living things adapt to their environment. Viruses do adapt to their environment. Sometimes, when a host cell loses enough energy needed by the virus to replicate, the virus switches to the lysogenic phase and will re-enter the lytic phase when cell conditions return to normal. The ability of viruses to quickly mutate is the PHILIPPINE SCIENCE HIGH SCHOOL SYSTEM Integrated Science 2 Page ​5​ of ​8  reason why human immunodeficiency virus (HIV) is hard to treat. Do viruses adapt to their environment? ​ ​☐ ​Yes ​☐ ​No Living things maintain homeostasis. Viruses cannot control their internal environment and maintain their own homeostasis. Do viruses maintain homeostasis? ​ ​Yes ☐ ​☐​ No Living things can move. Viruses cannot move without the help of a host cell. This is the main reason why during this pandemic, we are advised to stay at home because the lesser mobility of people, whether infected or not, the lesser the transmission of the virus, SARS-CoV-2, and the disease, COVID-19. Can viruses move by themselves? ​ ​☐ ​Yes ​☐​No Characteristics of Viruses Scorecard Yes No Are viruses composed of cells? Can viruses replicate on their own? Do viruses grow and develop? Do viruses get energy through metabolism? Do viruses adapt to their environment? Do viruses maintain homeostasis? Can viruses move by themselves? Navigate FORMATIVE ASSESSMENT 2: 5 min SARS-CoV-2 is the coronavirus that causes the current pandemic, COVID-19. Let us visualize a virus particle and its parts by creating a model of the HIV virus (refer to APPENDIX A). This activity requires the following materials: a pair of scissors, transparent adhesive tape, and coloring markers/pencils. PHILIPPINE SCIENCE HIGH SCHOOL SYSTEM Integrated Science 2 Page ​6​ of ​8  Based on your model virus: 1. What are the parts of the virus? ______________________________________________ 2. What category does your model virus belong to? ______________________________________________ 3. What genetic material does the virus have? ______________________________________________ a​ suggested time allocation set the teacher b​ actual time spent by the student References: Gelderblom, H. (1996). Structure and Classification of Viruses. In S. Baron (Ed.), ​Medical Microbiology (​ 4​th​ ed.). The University of Texas Medical Branch at Galveston. https://www.ncbi.nlm.nih.gov/books/NBK8174/ Kaiser, G. (2019). ​Size and Shapes of Viruses​. Biology LibreTexts. https://bio.libretexts.org/Bookshelves/Microbiology/Book%3A_Microbiology_(Kaiser)/ Unit_4%3A_Eukaryotic_Microorganisms_and_Viruses/10%3A_Viruses/10.02%3A_Si ze_and_Shapes_of_Viruses Khan Academy (n.d.). ​Are viruses dead or alive?​ Khan Academy. https://www.khanacademy.org/test-prep/mcat/cells/viruses/a/are-viruses-dead-or-aliv e Ryu, W. S. (2017). ​Virus Structure.​ ScienceDirect. https://www.sciencedirect.com/science/article/pii/B9780128008386000023 Steward, K. (2019, August 20). ​Lytic vs Lysogenic – Understanding Bacteriophage Life Cycles.​ Technology Networks. https://www.technologynetworks.com/immunology/articles/lytic-vs-lysogenic-understa nding-bacteriophage-life-cycles-308094 The Regents of The University of California. (2020, January 24). ​As Mysterious Coronavirus Spreads, An Infectious Disease Expert Explains What You Should Know.​ University of California San Francisco. https://www.ucsf.edu/news/2020/01/416511/mysterious-coronavirus-spreads-infectio us-disease-expert-explains-what-you Vogt, G.L. & Moreno, N.P. (2012). ​The Science of HIV/AIDS: The Virus, the Epidemic and the World.​ BioEd. http://www.bioedonline.org/BioEd/cache/file/EBEB131C-D34E-A025-CD1F1ED2CD4 97D13.pdf Prepared by: Reviewed by: Approved by: RANULFO F. CALA ROWENA M. LABRADOR REX S. FORTEZA Special Science Teacher II Special Science Teacher IV Special Science Teacher IV Central Visayas Campus Western Visayas Campus Central Luzon Campus PHILIPPINE SCIENCE HIGH SCHOOL SYSTEM Integrated Science 2 Page ​7​ of ​8 APPENDIX A. This activity is adopted from The Science of HIV/AIDS: The Virus, the Epidemic and the World (Vogt & Moreno, 2012). PHILIPPINE SCIENCE HIGH SCHOOL SYSTEM Integrated Science 2 Page ​8​ of ​8