Lecture I: Characteristics of Living Organisms & Levels of Biological Organization Flashcards
7 Characteristics of Living organisms
Have organized structure made up of organic molecules (molecules of life).
Are made up of one or more cells.
Grow, develop and reproduce.
Need energy to survive.
Respond to stimuli.
Maintain homeostasis.
Have the ability to evolve over generations.
What are the 4 organic molecules?
Protein, Carbs, Lipids, Nucleic Acids
What is the difference between growing and developing?
Growing: increase in size and cell number
Develop: Change in form (transformation)
Two types of reproduction?
Sexual/Asexual
What is energy used for?
Energy is taken in by living organisms to fuel metabolic reactions.
What is Metabolism?
The sum of all chemical reactions within living cells. It allows to perform all the chemical reactions that allow to do the necessary functions
What are the two types of stimuli?
Internal and external stimuli, which are both responses to changes in the environment, either internal (pH of blood) or external (predators).
Define homeostasis
The ability to maintain a specific internal environment.
What is an adaptation?
Traits that allow them to survive better in their environment will become more prevalent over time. These are called adaptations.
What are the 8 levels of Oragnization?
Atoms Molecules Organelles Cells Tissues Organs Organ systems Multicellular Organism
What is an organelle?
Organelles are the different distinct structures found within cells.
Each organelle has a specialized function.
Organelles are made up of molecules.
Examples include the nucleus and the mitochondrion
What is a cell?
The smallest level of organization that can sustain life
What are the 4 characteristics shared by all cells?
All cells are surrounded by a membrane.
All cells have internal mass (cytoplasm).
All cells contain genetic material (DNA).
All cells have ribosomes ( required to make proteins).
Characterize the Procaryotic cell.
Small in size 1 -10 µm
DNA not enclosed within it’s own membrane. DNA molecule is Circular in shape.
Lack membrane bound organelles
Have ribosomes (for protein synthesis)
Cytoplasm fills the cell.
Characterize the Eukaryotic cell
Larger in size 10 -100 µm
DNA is enclosed within it’s own membrane = nucleus
DNA molecules are linear strands.
Contain many membrane bound organelles each with specialized functions and Ribosomes.
Cytoplasm fills most of the cell, but is not found within the nucleus.
Define Tissues
A group of similar cells within an intercellular matrix (substance surrounding the cells) specialized to perform a specific function are called tissues.
e.g. Bone, muscle, nerve, etc…
Define Organs
Organs are made up of several different types of tissues, but they work together to perform the same function.
Define Organ Systems
Organs that work together to perform a particular function.
Define Living Organism
Independent living unit, composed of molecules, organelles, cells, tissues, organs and systems
Define Population
A group of individuals of the same species (unicellular or multicellular) living in the same area.
Define Community
Community ecology studies the interactions that occur between different species within a given area.
e.g. predator/prey
Ecosystem
All of the living organisms in a given area (the community or biotic component)
Plus,
The physical environment (abiotic component) they interact with.
Biosphere
The entire portion of Earth inhabited by living organisms
