2ND Q. EARTH AND LIFE SCIENCE POINTERS.pdf

EARTH AND LIFE SCIENCE POINTERS/REVIEWER 2nd Quarter Examination LESSON 1: INTRODUCTION TO LIFE Seven characteristics of life 1. ORDER- All living things must follow the biological hierarchy in the biosphere. 2. REP...

EARTH AND LIFE SCIENCE POINTERS/REVIEWER 2nd Quarter Examination LESSON 1: INTRODUCTION TO LIFE Seven characteristics of life 1. ORDER- All living things must follow the biological hierarchy in the biosphere. 2. REPRODUCTION - ability and capability to procreate new individuals (sexual and asexual means) 3. RESPONSE TO STIMULI - sensitivity to their environment. 4. HOMEOSTASIS - maintains an internal equilibrium when dealing with external changes 5. GROWTH AND DEVELOPMENT - change or gain an increase in their bodily structure - Growth refers to the increase in size and mass of an organism over time - Development refers to the progression of changes in structure, function, and complexity 6. ADAPTATION - evolve in order to adapt or fit on the changing environment. 7. METABOLISM - build-up and break down complex molecule inside their body. THEORIES IN THE ORIGIN OF LIFE THEORIES IN THE DEFINITION REASONS FOR REJECTION ORIGIN OF LIFE SPECIAL / DIVINE all things - the universe, the A. Lack of scientific evidence CREATION Earth, and all organisms, arise B. Life can occur in a laboratory using in-vitro THEORY due to the power of a Supreme fertilization and cloning techniques. being called “God”, the C. Believed as true only by faith and not by logical Almighty creator of Heaven and reasoning. Earth 2. PANSPERMIA life can be distributed throughout A. regarded as irrelevant since Earth is the only the universe, from planet to known planet capable of harboring life. planet through meteors and B. It is also very impossible for organisms to travel asteroids from one planet to another using meteors and asteroids alone. 3. SPONTANEOUS life may arise on non-life GENERATION (abiogenesis). 4. BIOGENETIC life occurs in pre-existing life. THEORY OR BIOGENESIS UNIFYING THEMES IN THE DEFINITION STUDY OF LIFE 1. CELL THEORY All organisms are composed of cells. It is summarized based on three statements: 1. All living things are made up of cells. 2. Cell is the basic unit of structure and function of organism. 3. Cell comes from pre-existing cells. 2. GENE THEORY that living organisms can pass on their traits or characteristics through their genes contained inside their genetic material called DNA. 3. STRUCTURE AND the structure of specific body parts always dictates its function. FUNCTION A. HOMOLOGOUS STRUCTURES - Same structure but different function B. ANALOGOUS STRUCTURES – same function but different structures 4. EVOLUTIONARY THEORY organisms come from a common ancestor who gradually evolve because of environmental changes. LESSON 2: PERPETUATION OF LIFE REPRODUCTION - A biological process by which new individual is produced from the parent ASEXUAL REPRODUCTION ✓ creation of new individual from a single parent ✓ does not require the fusion of gamete cells ✓ results to the formation of clone (natural process) Advantages: Faster and does not require lots of energy, Retention of useful characteristics Can work even if the organism is isolated Disadvantages: No variation, Susceptibility to disease, Competition for the same resources MODES OF ASEXUAL REPRODUCTION 1. BINARY FISSION - the parent cell divides into two new daughter cells with equal sizes. Examples Paramecium, Amoeba, E. coli 2. BUDDING - a new individual is formed from the outgrowth of the parent’s body. Example yeast cell, hydra, and corals 3. FRAGMENTATION – an organism breaks into fragments, and each fragment develops into a new, fully- formed individual. Example: planarian worm 4. REGENERATION – organisms regenerate lost or damaged body parts but typically do not reproduce new individuals. For healing, repair, and replacement of lost body parts (sometimes reproduction). Examples: sea stars, lizards, salamander, axolotl 5. PARTHENOGENIS - the female can produce an offspring from an unfertilized egg. A process where unfertilized eggs develop into female individuals without the need for fertilization by sperm. Example: honeybees, Komodo dragons SEXUAL REPRODUCTION – involves two parental organisms possessing different sex characteristics; requires the fusion of sperm and egg cells during fertilization Advantages: Variation of Species, Increased adaptability, Transfer of acquired characteristics Disadvantages: Genetic mutation, it takes longer period of time, Does not work if the organism is isolated INTERNAL FERTILIZATION – fertilization or fusion of gamete cells happen WITHIN the female’s body Examples: human, tiger, monkey, cow, goat, other retiles etc. EXTERNAL FERTILIZATION - fertilization or fusion of gamete cells happen OUTSIDE the female’s body or in the environment. The zygote develops outside the female body. Examples: frog eggs, salmon eggs  LESSON 3: GENES AND GENETIC ENGINEERING Genes – unit of heredity which is transferred from a parent to offspring Punnett square - A table in which all of the possible outcomes for a genetic cross between two individuals with known genotypes are given Example: H h H HH Hh h Hh hh GENETIC ENGINEERING - process of alteration, modification, or manipulation of organism’s genes using different techniques or technologies. SELECTIVE BREEDING - also known as artificial selection, involves the intentional mating of organisms with desirable traits to produce offspring with those specific characteristics. Ex. Cows, plants, dogs, cats etc. HYBRIDIZATION - involves breeding of individuals from two different species, genera, or populations with genetically determined differences. Examples: mule, liger, tigon, zorse, wholphin CLONING - technique or process that happens either through natural and artificial process that creates genetically identical individuals or exact copy of a certain organisms. Examples: natural way of cloning is asexual reproduction and mitotic cell division Dolly the sheep was the first mammal to be cloned from an adult somatic cell, using a technique called somatic cell nuclear transfer (SCNT). DNA RECOMBINATION Refers to the artificial creation of DNA sequences by combining genetic material from entirely different organisms using laboratory techniques. It involves the process of altering and modifying the organism’s genetic code that results in the creation of Transgenic organisms, commonly known as GMO GENETICALLY MODIFIED ORGANISM (GMO) are organisms—plants, animals, or microorganisms—whose genetic material (DNA) has been artificially manipulated in a laboratory through genetic engineering Examples: apples, potato, papaya, alfalfa, soybean, cotton, sugar beet, summer squash Advantages of Genetic Engineering and GMO Improvement of human life Maintenance of good environment through bioremediation Profit source Conservation of endangered species Creation of resistant crops with longer shelf life and increased nutrients  Disadvantages of Genetic Engineering and GMO Overly mutated genes, gene pollution, development of new diseases, and resistance to antibiotics. Reduced variation; and allergic reaction leading to susceptibility of the population Unethical LESSON 4: ORGAN SYSTEMS 1. INTEGUMENTARY SYSTEM - Hair, nails, and skin. Covers internal organs. External protection of the body against injuries and infections. Receive external stimulus 2. SKELETAL SYSTEM - All bones and joints. Protect and support body organs. Provides framework and causes movement. Produces new blood cells through the process of hematopoiesis. 3. MUSCULAR SYSTEM - Provides movement. Maintain posture and facial expression. Produces heat 4. NERVOUS SYSTEM - Organs: Brain, nerves, and spinal cord. Control all organs and body system through the neurons. Analyzes information and provides instructions to the organs of the body 5. REPRODUCTIVE SYSTEM - Elimination of waste and PROCREATION 6. CARDIOVASCULAR SYSTEM – Heart, blood, and blood vessels. Pump and deliver oxygenated blood and nutrients all throughout the body and get rid of carbon dioxide. 7. DIGESTIVE SYSTEM - Breaks down food materials into absorbable units needed for metabolic processes. Eliminates materials that are useless in the body via the fecal route 8. RESPIRATORY SYSTEM – nose, lungs, trachea, larynx. It provides oxygen to the body, disposes of carbon dioxide, and helps regulate blood pH level. 9. URINARY SYSTEM - Elimination of waste. Regulation of water and electrolytes. Balancing of acid- base composition of the blood. Organs: kidney, ureter, urinary bladder, & urethra 10. ENDOCRINE SYSTEM - Secrete hormones crucial for growth, reproduction, and metabolism Maintain internal balance of the body through the secretion of hormones needed for regulation 11. LYMPHATIC SYSTEM - Protects the body against pathogens, activates the immune response and protective cells, distinguishes body cells, and digests and destroys foreign substances that enter the body. LESSON 5:PROCESSES OF EVOLUTION EVOLUTION - process pertaining to the gradual change in the population of species over time.  Adaptive radiation in finches, a phenomenon first studied by Charles Darwin on the Galápagos Islands. Ancestor Finch. The image begins with a common ancestral finch species. These finches likely shared a similar habitat and had similar feeding habits. 1. Natural Selection. Over time, the ancestral finch population faced environmental pressures, such as competition for food resources. Natural selection favored individuals with beak shapes and sizes best suited to different food sources. 2. Divergence into Specialized Forms. The image shows how natural selection led to the evolution of different beak types, each adapted for specific diets: o Insect-eating: A narrow, pointed beak evolved for catching and consuming insects. o Woodpecker-type insect eating: A specialized beak adapted for extracting insects from wood or bark. o Seed-eating: A robust, thicker beak for cracking seeds. JEAN BAPTISTE LAMARCK Proposed the idea of “Theory of use and disuse” in which species undergo the process of transmutation whose physical characteristics were determined according to how often they use their body parts. CAROLUS LINNAEUS Proposed the science of “Taxonomy” in which he described that all organisms arise from a common ancestor. “Father of Taxonomy” developed the system of deriving the organism’s scientific name known as the “binomial nomenclature”. CHARLES DARWIN Pioneered the concept of evolutionary theory describing that species gradually evolve through the process of natural selection. NATURAL SELECTION Organisms that are best suited in the environment have a greater chance of survival. It was described as the survival of the fittest where the ability to adapt ensures survival and continuation of life. GENE FLOW Movement of genes from one population to another. When this happens, there will be an increase in the gene diversity of the population. It can occur through migration, pollination, and hybridization GENETIC DRIFT occurs when the frequency of certain genetic traits in a population changes due to random or chance events. These events can include factors such as genetic mutations, random mating, or the migration of individuals. MUTATION Occurs when there is a change in the genetic makeup, caused by environmental stressors like mutagens. - - - - - - - END - - - -