General Biology Chapter 1-3 Review Flashcards

Comprehensive practice question-and-answer flashcards covering key biological concepts, chemical foundations, and biological macromolecules from Chapters 1, 2, and 3 lecture notes.

How is biology defined in Chapter 1?

Biology is defined as the scientific study of life.

What is the structural and functional unit of life?

The cell.

What is metabolism?

All chemical reactions in the body through which organisms take in energy and use it to power all activities.

What is homeostasis?

The ability of an organism to maintain a beneficial internal environment through regulatory mechanisms.

What is taxonomy?

The branch of biology that names and classifies species and arranges species into a hierarchy of broader and broader groups.

What is the order of the taxonomic hierarchy from most general to most specific?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

What are the three higher levels of life known as domains?

Domain Bacteria, Domain Archaea, and Domain Eukarya.

What is binomial nomenclature?

A two-part, italicized scientific name given to each unique form of life that identifies its genus (capitalized) and particular species (lowercase), such as Homo sapiens.

What are emergent properties?

Novel properties that arise at each higher level of biological hierarchy and were not present at the preceding level, resulting from specific arrangements and interactions among component parts.

In an experiment, how do independent variables and dependent variables differ?

The independent variable (or experimental variable) is the factor manipulated by researchers, whereas the dependent variable (or responding variable) is the measure used to judge the outcome and depends on the manipulated variable.

What are the five unifying themes in biology?

1. Evolution is the core theme of biology. 2. Life depends on the flow of information. 3. Structure and function are related. 4. Life depends on the transfer and transformation of energy and matter. 5. Life depends on interactions within and between systems.

Which six chemical elements make up about $99\%$ of the weight of most living organisms?

Carbon, hydrogen, nitrogen, oxygen, calcium, and phosphorus.

What subatomic particles compose an atom, and where are they located?

Protons (positive charge) and neutrons (neutral charge) are located in the nucleus, while electrons (negative charge) are located in the electron cloud.

What is the atomic number of an element?

The number of protons in an atom (which also equals the number of electrons in an electrically neutral atom).

What are isotopes?

Atoms of the same element that have the same number of protons but different numbers of neutrons.

According to the octet rule and electron shell capacities, how many electrons can the first, second, and third electron shells hold?

The first shell holds up to $2$ electrons; the second and third shells hold up to $8$ electrons each.

What distinguishes a nonpolar covalent bond from a polar covalent bond?

In a nonpolar covalent bond, electrons are shared equally. In a polar covalent bond, electrons are not shared equally and are pulled closer to the more electronegative atom.

How does an ionic bond form, and what are cations and anions?

An ionic bond forms by the transfer of electrons between atoms. A cation is a positively charged ion that lost electrons, and an anion is a negatively charged ion that gained electrons.

How do cohesion and adhesion differ regarding water's life-supporting properties?

Cohesion is the tendency of molecules of the same kind to stick together, whereas adhesion is the clinging of one substance to another.

Why does ice float on top of liquid water?

Water is less dense as a solid than a liquid because as it freezes, each molecule forms stable hydrogen bonds with its neighbors, forming ice crystals where molecules are less densely packed.

What is the logarithmic nature of the pH scale?

Each unit on the pH scale represents a $10\text{-fold}$ change in the concentration of $H^+$ ions.

What is the function of a buffer?

A buffer is a substance that minimizes changes in pH by accepting $H^+$ when it is in excess (too acidic) or donating $H^+$ when it is depleted (too basic).

What are isomers?

Compounds that have the same molecular formula but different structures and therefore different properties.

What are the five functional chemical groups of organic compounds, and what property do they share?

Hydroxyl, carbonyl, carboxyl, amino, and phosphate groups. They are all polar and hydrophilic.

How do dehydration reactions and hydrolysis reactions differ in polymer building and breakdown?

Dehydration reactions link monomers together to form polymers by removing a water molecule, whereas hydrolysis reactions break polymers apart by adding a water molecule.

What are the storage and structural polysaccharides found in plants and animals?

Storage polysaccharides: Starch (in plants) and Glycogen (in animals). Structural polysaccharides: Cellulose (in plant cell walls) and Chitin (in insect/crustacean exoskeletons and fungal cell walls).

How do unsaturated fatty acids and saturated fatty acids differ structurally and physically?

Unsaturated fatty acids contain one or more double bonds and are liquid at room temperature (typical of plant oils). Saturated fatty acids contain the maximum number of hydrogens and are solid at room temperature (found in animal fats).

What is denaturation in proteins?

A process where a protein unravels, loses its specific shape, and consequently loses its function.

What are the four levels of protein structure?

1. Primary structure: sequence of amino acids in its polypeptide chain. 2. Secondary structure: coiling or folding of the chain, stabilized by hydrogen bonds. 3. Tertiary structure: overall three-dimensional shape resulting from interactions among R groups. 4. Quaternary structure: structure made of more than one polypeptide.

What three components make up a nucleotide monomer?

A 5-carbon sugar, a phosphate group, and a nitrogenous base.

What are the key structural and base differences between DNA and RNA?

DNA is a double helix containing deoxyribose sugar and the bases adenine, thymine, cytosine, and guanine. RNA is a single polynucleotide chain containing ribose sugar and the bases adenine, uracil, cytosine, and guanine.