Learning Activity Sheet Earth and Life Science
- 1. EARTH AND LIFE SCIENCE QUARTER 2 READINGS TOPIC: Evolving Concept of Life Based on Emerging Pieces of Evidence Have you been curious of when and where did life possibly start on Earth? During the 1800s, geologists and the naturalists found several forms of physical evidence that confirmed that Earth is very old. The evidence includes: fossils of ancient sea life on dry land far from oceans, this supported the idea that the Earth changed over time and some dry land today was once covered by oceans; the many layers of rock allowed the people to realize that rock layers represent the order in which rocks and fossils appeared, thus they were able to trace the history of Earth and life on Earth; lastly, the indications that volcanic eruptions, earthquakes and erosion that happened long ago shaped much of the Earth’s surface and supported the idea of an older Earth. This module will help you understand the historical development of the concept of life based on emerging pieces of evidence. This will trace back the events, processes, and living organisms existed on earth from the earliest time to present. Study this Timeline.
- 2. The universe is about 4.6 billion years old. Life on earth, probably began only between 3.5 and 4.0 billion years ago. Evidences from fossil records show the emergence of the different life forms. The common ancestor of all life was prokaryotic. Since, oxygen was scarce on the early Earth, so the ancestral cell must also have been an anaerobic. There are some challenges encountered in searching for the evidence of early life. Cells are microscopic and most have no parts to fossilize. The tectonic plate movements have destroyed nearly all rocks older than about 4 billion years, and most of the younger rocks have been heated or undergone processes that destroy the traces of biological material. At present, the oldest cell microfossils (microscopic fossils) are filaments from 3.5 billion-year-old rocks in Western Australia. The filaments resemble chains of modern photosynthetic bacteria and the rocks in which they occur are the remains of ancient stromatolites. The researchers look for biomarkers specific to eukaryotes. It is a substance that occurs only or predominantly in cells of a specific type. Eukaryotes are organisms having true nucleus. The DNA is enclosed within the nucleus whereas DNA of most prokaryotes lies enclosed in the cell’s cytoplasm. The first eukaryotes were protists. For life to evolve from simple single-celled organisms to many millions of species of prokaryotic species to simple eukaryotic species to all the protists, fungi, plants, and animals, took some time. The first life forms were very basic and this then allowed for the evolution of more complex life forms. Eukaryotic cells evolved from prokaryotic cells. The evolution of life is brought about the changes in the environment which are linked to changes in climate and geology. These Earth’s environmental changes made the Earth’s environment more suitable for a wider variety of life forms. Sequence of Events of the History of Life •The genus Homo gave rise to modern humans, Homo sapiens, us. It is estimated that they have been around for 2.3-2.4 million years, coinciding with the first evidence of stone tool usage. •The first mammals are our most direct ancestors, evolved from Amniotes. One of the earliest known mammals was Eozostrodon lived about 210 million years ago. •Studies of fossils from the Devonian Period 416-359 MYA indicates that land plants had evolved features we recognized today, such as leaves, roots and secondary wood. •Simple eukaryotes, but more advanced organisms, thought to developed 1.6 – 2.1 billion years ago •Oldest known fossilized prokaryotes have been dated approximately 3.5 billion years ago •Around 1.1 billion years ago multicellular organisms are thought to have started to develop. •Animals in the most basic sense of the word, have evolved from eukaryotes. Fossils of early sponges have been discovered in 665 million years old rock. •560 million years ago, some highly significant fossils of an organism which was named Charnia were discovered. These enigmatic early animals were anchored to the sea floor where they are thought to have absorbed nutrients.
- 3. ACTIVITY SHEET EARTH AND LIFE SCIENCE NAME:________________________________ General Instruction: From the Readings provided by the teacher, answer the following activities. Write your answers in this sheet of paper. ACTIVITY 1. Name It. Directions: Name the pieces of evidence on the evolution of life. Write your answer on the space provided. Pick your answer from the terms inside the box. ACTIVITY 2. ARRANGE ME. Directions: From the given statements below, arrange them to show the origin and evolution of eukaryotes. Number the boxes from 1-8, 1 as the earliest. Activity 3: Time to Reveal Directions: Arrange the jumbled word to reveal the evidence in the history of life on earth. Write the answer on the space below the grid.
- 4. ACTIVITY 4. MULTIPLE CHOICE. Directions: Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 1. Oxygen was scarce during the early development of Earth. By this situation, what kind of organism first existed? a. aerobic organism b. anaerobic organism c. mammal d. protist 2. Which of the following statements is NOT true on the evolution of multicellular organisms? a. The process of continuous specialization brought more complex organisms. b. The prokaryotic organisms that formed multicellular aggregates were like the cells of Cyanobacteria. c. They are believed to have evolved from single-celled prokaryotic organisms. d. They are formed from other multicellular colonial aggregates through cells specialization. 3. Why do you think the emergence of plants and animals came later than simple living organisms? a. Their existence is not that important on Earth. b. Their size is too big that it takes longer time for development. c. The cell structures of these multicellular organisms are more complex. d. These organisms are composed of many nucleus compared to unicellular. 4. Which statement is incorrect about living organisms? a. The earliest forms of life existed were the prokaryotes. b. The eukaryotic organisms evolved from the unicellular prokaryotic. c. Organisms did not change despite of the changes in the environment. d. Evolution of oxygen-producing organisms allowed the increase in the atmospheric oxygen. 5. Which of the following are in the correct order? a. eukaryotic cell, photosynthesis, prokaryotic cell, organic molecules b. eukaryotic cell, prokaryotic cell, organic molecules, photosynthesis
- 5. c. organic molecules, eukaryotic cell, photosynthesis, prokaryotic cell d. organic molecules, prokaryotic cell, photosynthesis, eukaryotic cell 6. What is the evidence for a last universal common ancestor among life on Earth? a. All look the same. b. They have similar synthesis pattern. c. All are classified as aerobic organisms. d. They share similar molecular features. 7. What unique substance do researchers look after in their study of eukaryotes? a. biomarkers b. fossils c. mitochondria d. stromatolites 8. Which of the following can be considered as a fossil? a. a billion-year old rock b. a billion-year old piece of amber c. a billion-year old amber with a primitive insect inside d. all of the choices are correct 9. Mainly the fossils are found on sedimentary rocks. What type of rocks are stromatolites? a. igneous b. metamorphic c. sedimentary d. trilobites 10.Which of the following is NOT true about the evidence that fossils provide? a. All fossils gathered contain intact DNA that can be sequenced. b. Fossil ages can often be determined by testing nearby rocks. c. Fossil organisms often share physical similarities with living organisms. d. Some fossil organisms are transitional forms between groups of organisms. 11.It was stated that the organisms are evolving. The evolution can be due to environmental changes. More so, the conservation of their traits depends mainly on how they will survive. In this regard, humans alter the natural world bringing harmful consequences from their activity. Which among the following refers to the alteration brought by humans to the natural environment? a. environmental issues b. ecosystem conflict c. environmental topics d. human intervention 12.What is the significance of studying the molecular evidence present among living organisms? a. It will benefit the economy of the world. b. It will give idea for the scientist which to clone. c. It will then serve as the basis of what to study. d. It will allow the classification of living organisms. 13.Over the past several decades, natural selection has caused populations of Staphylococcus aureus to evolve resistance to most antibiotics. What do you think would be the significance of being knowledgeable about the history of this organism towards antibiotics? a. It will just give them background about the microorganism. b. It will just give them idea of increasing the frequency of the organisms. c. It will give an idea of continuing the use of antibiotic against Staphylococcus aureus. d. It will give an idea for the medical team to discontinue the use of particular antibiotic resistant to that microorganism.
- 6. 14. The study of history of life is indeed significant. As part of searching for the fossils of previous organisms, stromatolite played a significant role. What is true about stromatolite? a. It is found on eukaryotes. b. It is produced by endosymbiosis. c. It is formed during volcanic eruptions. d. It consists of layered bacteria and sediment. 15. The following statements are challenges for the researchers in finding and identifying signs of early cells. Which is NOT part of the group? a. Cells are microscopic and most have no parts to fossilize b. Materials and testing laboratories are not available. c. Slightly younger rocks have been heated up and undergone other processes d. Tectonic plate movements have destroyed nearly all rocks older than about 4 billion years. Note: Pass this Activity Sheet on November 18, 2024. Keep the Readings and it will serve as your notes.