Biology Lecture Notes - Fundamentals: Organization, Biochemistry, Genetics, and Evolution

A set of practice questions covering core topics from the lecture notes: organization, energy flow, evolution, genetics, biochemistry, and molecular biology.

What is the smallest unit of biological organization?

Cell (enclosed by a membrane; includes prokaryotic and eukaryotic cells).

What are the two cellular domains and what organisms do they include?

Prokaryotic: Bacteria and Archaea; Eukaryotic: Eukarya.

What are the five unifying themes of biology?

Organization (cells); Information (genes, homeostasis); Energy processing (photosynthesis and cellular respiration); Interactions among components; Evolution.

What is the central dogma of molecular biology?

DNA is transcribed into RNA, which is translated into protein.

What is gene expression?

Converting information from a gene into a cellular product (protein or RNA).

What are the steps of the scientific method?

Observation, hypothesis, experiment, data collection/analysis, conclusion.

What are transcription and translation?

Transcription: DNA sequence is copied into RNA. Translation: RNA sequence is used to synthesize a protein.

What is a biosphere?

The sum of all ecosystems on Earth.

What is an ecosystem?

A community of organisms and the environment with which they interact.

What is a community in ecological terms?

A population of different species living in the same area.

What is a population in ecological terms?

A group of individuals of the same species living in a given area.

What are photosynthesis and cellular respiration?

Energy-processing processes: photosynthesis converts light energy to chemical energy; cellular respiration releases energy from sugars.

What is evolution in biology?

An explanation of unity and diversity in life; natural selection leads to adaptation and differential survival and reproduction.

What is natural selection?

Individuals with advantageous traits are more likely to survive and reproduce.

What is the atomic number of an atom?

The number of protons in the nucleus; determines the element.

What is an isotope?

Atoms of the same element with different numbers of neutrons, hence different masses; some are radioactive.

What is a covalent bond?

A bond formed when two atoms share electrons.

What is an ionic bond?

A bond formed by the attraction between oppositely charged ions after electron transfer.

What is a hydrogen bond?

A weak attraction between a partially positive hydrogen and a partially negative atom, important for water properties.

Why is water cohesive and have high surface tension?

Hydrogen bonding between water molecules creates cohesion and surface tension.

What causes water's high specific heat and high heat of vaporization?

Hydrogen bonding; energy is absorbed when bonds break and released when bonds form.

What is pH?

A measure of hydrogen ion concentration; acids have pH < 7, bases > 7, neutral 7.

What is a buffer?

A system that contains an acid-base pair and binds/releases H+ to resist pH changes.

What are the four major classes of macromolecules?

Carbohydrates, Proteins, Nucleic Acids, Lipids.

What is a monomer?

A single subunit that can join with others to form polymers.

What is a polymer?

A large molecule made of repeating monomers.

What are isomers?

Compounds with the same molecular formula but different structures; includes structural isomers, cis-trans (geometric) isomers, and enantiomers.

What is a carbohydrate monomer?

Monosaccharide (e.g., glucose, fructose, galactose).

What is a nucleotide made of?

A sugar (deoxyribose or ribose), a phosphate group, and a nitrogenous base.

What are the nitrogenous bases in DNA and RNA?

DNA: C, G, A, T; RNA: C, G, A, U.

What is the structure of DNA?

Double-stranded, stores genetic information.

What is the structure of RNA?

Usually single-stranded; functions in transcription and translation.

What is a phospholipid and its role in membranes?

Glycerol backbone with a phosphate group and two fatty acids; forms the phospholipid bilayer of cell membranes.

What are triglycerides and cholesterol?

Triglycerides: glycerol + three fatty acids; Cholesterol: a sterol lipid involved in membrane structure and signaling.

What is ATP and what does it do?

Adenosine triphosphate; the cell’s energy currency; ATP hydrolysis to ADP releases energy.

What is dehydration synthesis and hydrolysis?

Dehydration synthesis forms polymers by removing water; hydrolysis breaks polymers by adding water.

What is the role of proteins in cells?

Enzymes; defense; transport; signaling; receptors; movement; and structural support.

What is genomics and proteomics, and what field supports them?

Genomics analyzes large sets of genes; Proteomics analyzes large sets of proteins; both rely on bioinformatics.