Introduction to Life Science (ELS) Week 1 Module 2Q PDF

ORIGIN AND STRUCTURE OF THE EARTH SECOND QUARTER | EARTH & LIFE SCIENCE INTRODUCTION TO LIFE SCIENCE Earth and Life Science THE UNIVERSE, SOLAR SYSTEM, AND EARTH SHS 11 | STEM...

ORIGIN AND STRUCTURE OF THE EARTH SECOND QUARTER | EARTH & LIFE SCIENCE INTRODUCTION TO LIFE SCIENCE Earth and Life Science THE UNIVERSE, SOLAR SYSTEM, AND EARTH SHS 11 | STEM Duration: 1 Week ILIGAN COMPUTER INSTITUTE Ground floor MJK Building, Mabini corner M. H. Del Pilar Iligan City, 9200, Philippines +63-917-322-4133 | 228-1008 INTRODUCTION TO LIFE SCIENCE Target Competencies: In this chapter, you are expected to: 1. explain the evolving concept of life based on emerging pieces of evidence 2. describe how unifying themes (e.g., structure and function, evolution, and ecosystems) in the study of life show the connections among living things and how they interact with each other and with their environment. INTRODUCTION Life is believed to have existed on earth for billions of years now. Scientists do not know exactly when life began on Earth. However, they are able to trace how life developed and evolved using some pieces of evidence. Although scientists cannot directly address how life on Earth arose, they can formulate and test hypotheses about natural processes that could account for various intermediate steps, consistent with the geological evidence. THE ORIGIN OF LIFE PRIMORDIAL SOUP THEORY It was proposed by Alexander Oparin and John Haldane It had been theorized that life started in the oceans. Oparin and Haldane thought that with the mix of gases in the atmosphere and the energy from lightning strikes, amino acids could spontaneously form in the oceans. Oparin believed that organic molecules had developed from the gases of Earth’s early atmosphere. However, he wasn’t able to perform the experiments. MILLER AND UREY EXPERIMENT In 1953, American scientists Stanley Miller and Harold Urey tested the Primordial Soup theory. ▪ They combined the atmospheric gases in the amounts that early Earth's atmosphere was thought to contain. Stanley Miller and Harold Urey were the first to show organic molecules could be made from inorganic compounds. This groundbreaking experiment seemed to prove that life on Earth could have spontaneously formed from Figure 1: Miller–Urey Experiment; Retrieved: www.nomadicexperiences.com nonorganic ingredients. EARLY FORMS OF LIFE The first form of life is believed to have appeared some 3.5 billion years ago. The first evidence of life is found in microfossils. Microfossils are fossils that contain the remains of tiny plants and animals. They are very small and can be measured in millimeters, and some could only be identified under a microscope. ES | ELS | G11 | 2 INTRODUCTION TO LIFE SCIENCE Some of the remains of organisms do not have a nucleus so they were called prokaryotes. They are known to be the earliest forms of life. They have survived the extreme conditions of the early environment. They started to make their own food by utilizing the energy from the sun and the carbon dioxide in the atmosphere. These are the photosynthetic organisms. The process of photosynthesis produced more oxygen that changed the Earth’s early atmosphere. This change in the atmosphere allowed oxygen-breathing organisms to exist. The cyanobacteria are the first photosynthetic organisms to form. Their microfossils are among the easiest to recognize. The first microfossil that showed remains of organisms with differences in structure from the simple form of life was seen in rocks about 1.5 billion years old. HOW DID MULTICELLULAR ORGANISMS EVOLVE? Multicellular organisms are believed to have evolved from unicellular eukaryotes. Some single eukaryotic cells, like unicellular algae, formed multicellular aggregates through association with another cell producing colonies. The first fossilized animals which were discovered 580 million years ago were soft-bodied. Evidence from fossil layers proved that different forms of life were present and has evolved through time. Eukaryotes are organisms consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus. These findings marked the beginning of eukaryotic organisms on Earth. CHARACTERISTICS OF LIFE The characteristics common to all living things that are considered in the study of life are cellular organization, metabolism, homeostasis, reproduction, and heredity. Cellular Organization All cells have the same basic structure: a membrane that encloses the cell and controls materials that move in and out; an internal fluid known as the cytoplasm where the organelles are suspended; and a nucleus that contains the hereditary genes called DNA. 1. Cell Structure and Function All living organism are composed of cells Cell is the basic unit of structure & function Structure and Function relationship is apparent in the entire organism and the physiological system that serve them. The structure determine function, function reflects structure. 2. Metabolism Sum of all chemical energy transformation in an organism Living organism use energy to stay alive, grow 3. Homeostasis Maintaining a stable internal environment with respect to the external. All living things maintain stable internal conditions. While the environment often varies a lot, organisms act to keep their interior conditions relatively constant in a process called homeostasis. 4. Reproduction The offspring inherits units of information called genes from their parent Genes- responsible for family resembles Made up of information rich molecule called DNA DNA (Deoxyribonucleic acid) is a large molecule containing the hereditary material of the cell. 5. Heredity ES | ELS | G11 | 3 INTRODUCTION TO LIFE SCIENCE Genetic heritage passed down by our biological parents. All organisms possess a genetic system that is based on the replication and duplication of a long molecule called deoxyribonucleic acid (DNA). The information that determines what an individual organism will be like is written in a code dictated by the sequence of the DNA molecule. Each set of instruction within the DNA is called a gene. UNIFYING THEMES IN LIFE SCIENCE In addition to the characteristics, certain topics also tie life science together. Levels of organization, the flow of energy, evolution, interacting systems, form and function, ecology, and science and society are these six overarching topics. 1. Levels of Organization There is a hierarchy of increasing complexity within cells, from the molecular level of DNA (where the chemistry or life occurs), to the organelle level (where the cellular activities are organized), to the cellular level (the smallest level of organization). 2. The Flow of Energy Energy is used by organisms to grow and do work. Without it, life stops. Almost all the energy that living things need is obtained from the sun. Plants capture the energy from sunlight and use it to make complex molecules in a process called photosynthesis. These molecules then serve as the source of fuel for animals that eat them. The flow of energy among organisms helps determine how organisms interact within their environment 3. Evolution The theory of evolution helps explain how all kinds of organisms came into existence. It explains why organisms look the way they do, and how organisms of the past are related to the organisms alive today. Charles Darwin proposed the theory of evolution by natural selection which presumes that organisms with more favorable traits would be more likely to survive and reproduce in a certain environment. These favorable traits are called adaptations. For example, the cactus plant is adapted to a desert environment. In time, organisms that lack the necessary adaptations would die out, and all individuals with favorable adaptations would live on. 4. Interacting Systems Living things interact with each other and with the environment. A living community is highly structured and interdependent. This interdependence is the result of a long process of evolution in which selection has favored cooperation. For example, animal cells that descended from symbiotic bacteria possess organelles, and symbiotic fungi helped plants move from sea to land. The coevolution of flowering plants and insects has been responsible for the diversity of both species. 5. Structure and Function A relationship exists between structure and function at all levels of biological organization. In biology, structure is always related to function. Hence, the hierarchy of structural levels is the basis for the biology organization. Structural levels are built on the levels that preceded it. Within the many kinds of organisms in the living world, body structures seem to be carefully designed to carry out their functions. For example, hummingbird sucks nectar from a deep flower through its long tongue. ES | ELS | G11 | 4 INTRODUCTION TO LIFE SCIENCE 6. Ecology The study of complex communities of organisms in relation to their environment. Organisms’ need the physical environment to survive. They need substances like water, nutrients, and gases from the environment. The stability of the environment, in turn, depends on the healthy functioning of organisms in that environment. For example, all organisms depend on the oxygen-carbon dioxide cycle, which releases vital gases in the atmosphere. However, this complex web of interactions is easily disrupted when the environment is polluted and individual species become extinct, similar to what is happening in the world today. 7. Science and Society Knowledge from biological science can be applied to specific problems in the society to improve human life. For example, the development of a vaccine against poliomyelitis virus in the 1950s was a scientific breakthrough that had a large impact on society. By producing the polio vaccine in bulk and distributing it throughout the world, scientists, business leaders, and governments have worked together to reduce the threat of polio. ES | ELS | G11 | 5 INTRODUCTION TO LIFE SCIENCE SUPPLEMENTAL VIDEOS/READING MATERIAL LINKS: 1. Ecosystem https://education.nationalgeographic.org/resource/ecosystem/?utm_source=Bibblio RCM_Row 2. What Darwin Didn't Know About Evolution: https://www.nationalgeographic.com/science/2018/09/darwin-evolution-crispr- microbiome-bacteria-news/ 3. 5 vital roles insects play in our ecosystem: https://www.nationalgeographic.com/magazine/article/insects-play-these-five-vital- roles-in-our-ecosystem-feature 4. Making sense of how life fits together https://www.youtube.com/watch?v=IYSlId-Ri7Q&authuser=0 5. The Costs and Benefits of Environmental Changes https://www.nationalgeographic.org/idea/costs-benefits-environmental- changes/?utm_source=BibblioRCM_Row&authuser=0 6. Introduction to Biology https://www.youtube.com/watch?v=7L7x0BAqWis&authuser=0 ES | ELS | G11 | 6