organic

Examples of organic in the following topics:

• Plant Tissues and Organ Systems

• More complex organic molecules and life

• Strategies for Acquiring Energy

  • It is important to understand how organisms acquire energy and how that energy is passed from one organism to another through food webs and their constituent food chains.
  • Food webs illustrate how energy flows directionally through ecosystems, including how efficiently organisms acquire it, use it, and how much remains for use by other organisms of the food web.
  • Without these organisms, energy would not be available to other living organisms and life itself would not be possible.
  • The energy stored in ATP is used to synthesize complex organic molecules, such as glucose.
  • If they cannot eat other organisms, they will die.

• Types of Skeletal Systems

  • A skeletal system is necessary to support the body, protect internal organs, and allow for the movement of an organism.
  • This compartment is under hydrostatic pressure because of the fluid and supports the other organs of the organism.
  • Lengthening the body extends the anterior end of the organism.
  • Most organisms have a mechanism to fix themselves in the substrate.
  • Although a hydrostatic skeleton is well-suited to invertebrate organisms such as earthworms and some aquatic organisms, it is not an efficient skeleton for terrestrial animals.

• Cells as the Basic Unit of Life

  • A cell is the smallest unit of a living thing and is the basic building block of all organisms.
  • A living thing, whether made of one cell (like bacteria) or many cells (like a human), is called an organism.
  • Thus, cells are the basic building blocks of all organisms.
  • Several cells of one kind that interconnect with each other and perform a shared function form tissues; several tissues combine to form an organ (your stomach, heart, or brain); and several organs make up an organ system (such as the digestive system, circulatory system, or nervous system).
  • Several systems that function together form an organism (like a human being).

• Signaling Molecules and Cellular Receptors

  • Cellular communication ensures regulation of biological processes within various environments from single-celled to multicellular organisms.
  • This is true whether a cell is growing by itself in a pond or is one of many cells that form a larger organism.
  • In multicellular organisms, cells send and receive chemical messages constantly to coordinate the actions of distant organs, tissues, and cells.
  • While the necessity for cellular communication in larger organisms seems obvious, even single-celled organisms communicate with each other.
  • Some forms of bacteria coordinate their actions in order to form large complexes called biofilms or to organize the production of toxins to remove competing organisms.

• Properties of Life

  • In multicellular organisms , similar cells form tissues.
  • Organs work together to form organ systems.
  • Single-celled organisms reproduce by first duplicating their DNA.
  • All organisms use a source of energy for their metabolic activities.
  • A toad represents a highly organized structure consisting of cells, tissues, organs, and organ systems.

• Levels of Organization of Living Things

  • Organs are present not only in animals but also in plants.
  • An organ system is a higher level of organization that consists of functionally related organs.
  • Mammals have many organ systems.
  • Furthermore, organisms are individual living entities.
  • For example, each tree in a forest is an organism.

• Food Chains and Food Webs

  • Both energy and nutrients flow through a food web, moving through organisms as they are consumed by an organism above them in the food web.
  • In both food webs and food chains, arrows point from an organism that is consumed to the organism that consumes it.
  • Some lines within a food web may point to more than one organism; those organisms may occupy different trophic levels depending on their position in each food chain within the web .
  • A detrital food web consists of a base of organisms that feed on decaying organic matter (dead organisms), called decomposers or detritivores.
  • These organisms are usually bacteria or fungi that recycle organic material back into the biotic part of the ecosystem as they themselves are consumed by other organisms.

• The Respiratory System and Direct Diffusion

  • Respiratory processes that help organisms exchange O2 and CO2 range from simple direct diffusion to complex respiratory systems.
  • The oxygenated air crosses the lung tissue, enters the bloodstream, and travels to organs and tissues.
  • All aerobic organisms require oxygen to carry out their metabolic functions.
  • The complexity of the respiratory system correlates with the size of the organism.
  • For small multicellular organisms, diffusion across the outer membrane is sufficient to meet their oxygen needs.