SL

ELS_GR11 MAD_2ND QUARTER REVIEWER

Page 1: Introduction to Life Science

Overview

  • Earth and Life Science topics covered include:

    • Introduction to Life Science

    • Cell Theory, Parts, Functions, and Transport

    • Cell Cycle

    • DNA, RNA, Central Dogma

    • Photosynthesis

    • Cell Respiration

Biology

  • Definition: Study of structures, functions, and relationships of living organisms with their environment.

Hierarchy of Life

  • Cell: Basic unit of life.

  • Tissue: Group of specialized cells working together for a specific function.

  • Organ System: Collection of organs performing specific functions.

  • Organism: A living thing that carries out all life functions.

Primordial Soup Theory (Oparin)

  • Life began from a mixture of inorganic molecules (methane, nitrogen, ammonia, etc.).

  • Energy from the sun fueled chemical reactions that formed complex molecules leading to life.

Branches of Biology

  • Various fields exploring living organisms and their interactions with the environment.

Page 2: Theories of Life Origin

Miller-Urey Experiment

  • Simulated ancient Earth conditions; produced organic molecules from inorganic substances.

Abiogenesis

  • Description: Spontaneous generation of life from non-life through energy-induced interactions of organic molecules.

  • Historically supported by Ancient Egyptians, Aristotle, John Needham.

Biogenesis

  • Definition: Life arises from pre-existing life.

  • Key scientists:

    • Francesco Redi: Experimented with jar conditions to test spontaneous generation.

    • Lazzaro Spallanzani: Extended Needham's experiment to kill microorganisms.

    • Louis Pasteur: Enhanced Spallanzani's findings, affirming biogenesis.

Creationism

  • Belief in a supernatural being's role in creating life and the universe.

  • Philippine Version: Malakas at Maganda, a creation myth similar to Adam and Eve.

The Theory of Evolution

  • Living organisms evolve over time, adapting their structures and functions in response to environmental changes.

Page 3: Comparative Anatomy and Evolution

Structural Comparisons

  • Homologous Structures: Same origin, different function.

  • Analogous Structures: Different origin, similar function.

Notable Figures

  • George-Louis Buffon: Contributed to understanding of thermophiles.

  • Charles Darwin: Introduced "Survival of the Fittest".

  • Jean Baptiste Lamarck: Proposed that organism traits develop through use (Lamarckism).

Panspermia/Cosmozoic Theory

  • Life on Earth potentially started from extraterrestrial origins; lacks scientific evidence.

Page 4: Cell Types and Structure

Prokaryotes vs. Eukaryotes

  • Prokaryotes: Single-celled organisms without a defined nucleus; abundant on Earth.

  • Eukaryotes: Multicellular organisms with a defined nucleus containing DNA.

Types of Eukaryotic Cells

  • Plants: Cellulose cell wall, chloroplasts, vacuoles.

  • Animals: No cell wall, may have flagella.

  • Protists: Cell wall but lack differentiated tissues.

  • Fungi: Chitin cell wall; heterotrophs.

Page 5: Structure and Function of Cells

Basic Cell Structures

  1. Cell Membrane:

    • Selective barrier regulating material passage.

  2. Cytoplasm:

    • Gel-like substance for biochemical reactions and metabolic support.

  3. Cell Nucleus:

    • Control center housing DNA and facilitating ribosome synthesis.

Protein Synthesis

  • Ribosomes: Synthesize proteins using mRNA.

Endoplasmic Reticulum (ER)

  • Network of membranes:

    • Rough ER: Ribosomes present; protein synthesis/modification.

    • Smooth ER: Lipid synthesis, carbohydrate metabolism, detoxification.

Page 6: Energy and Cellular Digestion

Golgi Apparatus

  • Processes, packages proteins/lipids from ER; maintains internal balance.

Mitochondria

  • Known as Powerhouse of the Cell; generates energy via cellular respiration.

Endosymbiotic Theory

  • Eukaryotic cells evolved from engulfed prokaryotic cells.

Chloroplasts

  • Exclusive to plant cells; responsible for photosynthesis.

Types of Plastids

  • Chloroplasts: Photosynthesis.

  • Chromoplasts: Plant pigments.

  • Leucoplasts: Non-pigmented, starch storage (

Cellular Digestion

  • Lysosomes: Digest unwanted materials.

  • Peroxisomes: Degrade toxins, regulating metabolism.

Page 7: Cell Support and Movement

Cytoskeleton

  • Provides support and enables movement; crucial for cell stability.

Flagella/Cilia

  • Flagella: Elongated structures for protist motility.

  • Cilia: Shorter structures aiding in fluid movement over cell surfaces.

Storage and Transport

  • Vesicles/Endosomes: Transport materials between organelles.

Differences in Cell Types

  • Animal Cells: Smaller, lack cell walls/chloroplasts.

  • Plant Cells: Rigid cell walls, contain chloroplasts.

Page 8: Cell Transport Mechanisms

Cell Membrane Functions

  • Separates cell from environment, regulates material flow, maintains homeostasis.

Types of Cell Transport

  • Active Transport: Requires energy (e.g., endocytosis).

  • Passive Transport: No energy needed (e.g., diffusion).

Cell Tonicity

  • Refers to water movement affecting cell volume.

Endocytosis/Exocytosis

  • Endocytosis: Bulk transport into the cell.

  • Exocytosis: Bulk transport out of the cell.

Page 9: Cell Cycle and Disorders

Phases of Cell Cycle

  • G1: Growth phase.

  • S: DNA copying.

  • G2: Preparation for division.

  • M: Mitosis.

Genetic Conditions

  • Klinefelter Syndrome (47, XXY): Additional X chromosome leads to physical characteristics.

  • Turner Syndrome (45, XO): Absence of X chromosome.

  • Cri-Du-Chat Syndrome (46, 5p-): Partial loss of chromosome 5.

  • Down Syndrome (47, 21+): Trisomy 21 with distinctive eye folds.

  • Edward Syndrome (47, 18+): Trisomy with severe developmental issues.

  • Patau Syndrome (47, 13+): Similar to Edward syndrome, early mortality.

Page 10: DNA and Genetic Information

DNA Structure

  • Definition: Molecule carrying genetic instructions, discovered through inheritance studies.

  • Double Helix: Twisted structure with bases (A, C, G, T).

Nucleotide Composition

  • Pyrimidines: Cytosine and Thymine.

  • Purines: Adenine and Guanine.

DNA Replication

  • Process of duplicating DNA before cell division.

mRNA and Protein Synthesis

  • mRNA: Transmits genetic information from DNA to ribosomes.

  • Translation: Protein synthesis based on mRNA template.

Page 11: Photosynthesis and Cellular Respiration

Photosynthesis Overview

  • Converts light energy to chemical energy in glucose; requires sunlight, carbon dioxide, and water.

  • Occurs in mesophyll cells of leaves.

Light Reactions

  • Light-dependent reactions capturing sunlight energy.

Cellular Respiration

  • Converts sugars to usable energy; involves Glycolysis, Krebs Cycle, and Electron Transport Chain.