Bio 103: Levels of Organization and Scientific Principles

Comprehensive flashcards covering biology definitions, levels of organization, atomic structure, organic/inorganic molecules, macromolecules, and the scientific method.

What is the definition and origin of the word Biology?

Biology is the study of life, coming from Bios meaning life and logia meaning study, encompassing anything that impacts living things.

What is the Major Principle of Biology regarding levels of organization?

God made the world so that each level of organization is a building block of the next more complex level.

What are the 13 levels of organization in order from simplest to most complex?

1. Subatomic particles, 2. Atoms, 3. Molecules, 4. Organelles, 5. Cells, 6. Tissues, 7. Organs, 8. Organ systems, 9. Multicellular organisms, 10. Populations (species), 11. Communities, 12. Ecosystems, 13. Biospheres.

What are the three types of subatomic particles and their characteristics?

Protons are heavy with a positive charge ($\text{P}^+$), neutrons are heavy with a neutral charge ($\text{N}$), and electrons are light with a negative charge ($\text{e}^-$).

What components form the core of an atom's nucleus?

Protons and neutrons form the core of the nucleus, which attracts electrons.

How many natural types of atoms exist, and what are they called in pure form?

There are 92 natural types of atoms, which are called elements in their pure or simple form.

Which element is the most complex atom found in nature?

Uranium is the most complex element found in nature.

What does CHNOPS stand for, and what percentage of living tissue does it compose?

CHNOPS stands for Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur. These six elements make up 97–99% of living tissues.

How are chemical bonds defined?

Chemical bonds are forces that hold atoms together in molecules, depending on the number of electrons.

What are the electron stability rules for electron shells?

Electron shells are stable when the first shell has $2\,\text{e}^-$ and the second and third shells have $8\,\text{e}^-$.

Why does Neon rarely form molecules?

Neon ($\text{Ne}$) has happy shells, meaning it already has the maximum number of electrons in each shell.

What is an ion and what defines an ionic bond?

An ion is an atom with a net electrical charge. An ionic bond is formed by electrical forces that attract and hold oppositely charged ions together when electrons are transferred.

What is a covalent bond and how is it represented in structural formulas?

A covalent bond is formed when atoms share electrons in their outermost shell (electrons are not exchanged). It is represented by a solid line ($-$).

What chemical criteria distinguish organic molecules from inorganic molecules?

Organic molecules are large and complex and MUST contain $\text{C}-\text{H}$ bonds. Inorganic molecules are simple and do not contain $\text{C}-\text{H}$ bonds.

Why are water ($\text{H}_2\text{O}$) and carbon dioxide ($\text{CO}_2$) classified as inorganic molecules?

They are simple molecules that lack $\text{C}-\text{H}$ bonds.

What are the four main groups of organic molecules?

Carbohydrates, Lipids, Proteins, and Nucleic Acids.

What elements make up carbohydrates and what are their 5 types?

Carbohydrates always contain $\text{C}$, $\text{H}$, and $\text{O}$. The 5 types are Sugars (main energy source and building blocks), Starch (main energy storage), Glycogen (energy storage in animals), Cellulose (plant cell walls), and Chitin (exoskeletons and fungi cell walls).

What are the four main functions of lipids?

1. Energy storage, 2. Structural (cell membranes), 3. Protective (around inner organs), 4. Regulatory (many hormones are lipids).

What are the building blocks of proteins and how many are essential?

Amino acids are the building blocks of proteins. There are 20 different types of amino acids, 8 of which are essential (cannot be naturally produced by the body).

What structural feature differentiates one amino acid from another?

All amino acids share the same basic structure, but their side groups differentiate them.

What are the six main types and functions of proteins listed in the notes?

1. Regulatory (enzymes, ADH), 2. Energy storage (eggs/yolk), 3. Transport (blood, $\text{O}_2$), 4. Movement (muscles), 5. Protection (antibodies), 6. Structural (cartilage, feathers, keratin).

What are the three types of nucleic acids and their functions?

1. DNA (cellular info, instructions/codes of life), 2. RNA (helps create proteins), 3. ATP (energy carrier).

What are organelles and what are they composed of?

Organelles are small structures inside the cell that each perform a specific function (e.g., nucleus, mitochondria, ribosomes). They are made up of organic molecules.

How is a cell defined at the cellular level?

A cell is the smallest living unit, existing as unicellular organisms (e.g., bacteria) or multicellular organisms (e.g., humans, plants, animals).

What does it mean that life is an emergent property?

It means complexity arises from the interaction of simpler components; the whole is greater than the sum of its parts because of interactions.

What is the origin and definition of science in the lecture notes?

Science comes from the Latin scientia meaning to know or knowledge. It is a multi-step process to acquire knowledge as well as a collective body of information.

According to the notes, what bird group are falcons closest to?

Falcons are closer to parrots than hawks.

What are the four steps of the scientific method?

1st Step: Observation of natural phenomena. 2nd Step: Formulate hypothesis (must be testable and falsifiable). 3rd Step: Conduct experiments to test hypothesis. 4th Step: Draw conclusion that accepts, rejects, or modifies hypothesis.

What is the cardinal rule regarding hypotheses in science?

NEVER prove a hypothesis.

What are the seven properties or attributes of living things?

1. Composed of cell(s), 2. Highly organized and complex, 3. Use energy, 4. Grow, develop, reproduce, control internal environment, 5. Respond to stimuli, 6. Ability to change (pass on genes), 7. Death.

What are the definitions of tissues, organs, and organ systems?

Tissues are groups of cells with structural/functional roles; Organs are structures with specific functions (e.g., stomach, brain, leaf, roots); Organ systems are groups of organs working towards a specific goal (e.g., digestive system).

What are the definitions of population, community, ecosystem, and biosphere?

Population is a group of individuals of the same species in an area; Community is all different species in an area; Ecosystem includes living (biotic) and non-living (abiotic) elements in the physical environment; Biosphere is all ecosystems together on Earth (most complex level).

What is the distinction between biotic and abiotic factors?

Biotic factors are living components, while abiotic factors are non-living components (e.g., air, water, oxygen).