Module 2 (The Levels of Organization of Living Things)

• Living organisms are characterized by a highly organized structure and arranged in a hierarchical pattern.
• At the smallest scale is an atom, the fundamental unit of matter. When atoms combine, they form molecules.
• is a chemical structure consisting of at least two atoms held together by one or more chemical bonds.

  Molecule
• Many biologically important molecules are macromolecules, examples are proteins, lipids, carbohydrates, and nucleic acid like your DNA which contains the instructions for the structure and function of your body.
• These molecules can form organelle, a structure that has a specific function within the cell. An example of this includes the mitochondria which can be found in both animals and plants, and chloroplast which is present mostly in plants.
• Mitochondria produce energy to power cells.
• Chloroplast enables green plants to utilize the energy in sunlight to make sugars.
• Cell is the basic building block of all organisms. It is structural and functional unit of life.
• Some organisms consist of single cells and others are multicellular. Some examples of cells that can be found in humans include RBCs, brain cells, skin cells, liver cells, etc.
• Cells are classified as prokaryotic and eukaryotic.
• Prokaryotes are single-celled organisms that do not have membrane-bound organelles.
• An example of prokaryotic organisms are bacteria, some fungi, protozoa, algae, etc.
• Cells of eukaryotes have membrane-bound organelles like the nucleus.
• Eukaryotic organisms are animals such as humans, plants, and some fungi.
• In larger organisms, cells combine to make tissues which are group of similar cells performing specific functions within an organism.
• The 4 main types of tissues in animals namely; epithelial tissues, connective tissues, muscle tissues, and nervous tissues.
• The 3 main types of tissues in plants namely; vascular, dermal, and ground tissues.
• When there is a layer of tissues working together, they form an organ.
• Organs are collections of tissues grouped performing a common function, it is not only present in animals but also in plants.
• Mammals have five vitals organs that they cannot live without like kidneys, lungs, liver, heart, and brain.
• In plants, the major organs include the leaf, stem, root, and reproductive structures.
• When a group of organs combine, they form an organ system.
• is a higher level of organization that consists of functionally related organs.

  organ system
• are living individual entities, simply defined as any living thing that is composed of various organ systems that function altogether.

  Organisms
• A group of organisms of the same species living together within a specific area/habitat are collectively called populations.
• A forest of pine trees includes populations of flowering plants, animals, and microorganisms which is called a community.
• is a group of organisms composed of different species living together and interacting in a certain area or habitat.


  Community
• All trees, flowers, insects, microorganisms, and other populations community, the forest itself is an ecosystem.
• is a group of organisms having an interaction or interrelationship with the non-living environment such as air, nitrogen in the soil, or rainwater.

  ecosystem
• At the highest level of organization is the biosphere.
• The biosphere is the global sum of all ecosystem, and it represents the zones of life on Earth which means a part of the planet that is capable of supporting life. It includes land, water, and even the atmosphere to a certain extent.