Foundations of Biology – Lecture 1

These flashcards cover the main ideas from Lecture 1, including levels of organization, evolution, genomics, taxonomy, scientific method, model-based learning, and foundational chemistry required for biology.

What national initiative was launched in 2007 to modernize undergraduate biology education?

Vision and Change in Undergraduate Biology, proposed by NSF with HHMI, NIH, and AAAS.

List the five core concepts of biology outlined by Vision and Change.

Evolution; Structure and Function; Information Flow, Exchange, and Storage; Pathways and Transformations of Energy and Matter; Systems.

What is the smallest level in the biological hierarchy that still retains the chemical properties of an element?

An atom.

Place these levels in order from simplest to most complex: Organ, Tissue, Ecosystem, Cell.

Cell → Tissue → Organ → Ecosystem.

Define ‘population’ in biological terms.

A group of organisms of the same species living in the same environment.

Which level of organization includes all regions on Earth where living organisms exist?

The biosphere.

What does biological evolution describe?

Heritable change in a population of organisms from one generation to the next.

How old are the earliest primitive cells believed to be?

Between 3.5 and 4 billion years old.

Give an example of modification of pre-existing structures in evolution.

Walking limbs modified into a dolphin’s flipper or a bat’s wing.

What molecule stores hereditary information in almost all living organisms?

DNA (deoxyribonucleic acid).

What is a gene?

A segment of DNA that governs the traits of an organism, typically transcribed into mRNA and translated into a polypeptide.

Define mutation.

A heritable change in the genetic material.

Describe vertical descent with mutation.

Evolutionary changes in a lineage where new species arise from pre-existing ones by accumulation of mutations; natural selection favors beneficial mutations.

What is horizontal gene transfer?

The movement of genetic material from one organism to another that is not its offspring.

Why is the ‘web of life’ considered more complete than the ‘tree of life’?

It incorporates both vertical evolution and horizontal gene transfer events among species.

What is a genome?

The complete genetic material of an organism.

Define proteome.

The full complement of proteins produced by an organism.

What term describes techniques used to analyze all genes of a species?

Genomics.

What is artificial selection?

Human-directed breeding to enhance desired traits in domesticated species.

Which experiment demonstrated artificial selection in canids?

The 40-year study selecting tame behavior in red foxes (Vulpes vulpes).

Name the three domains of life.

Bacteria, Archaea, and Eukarya.

Which two domains are prokaryotic?

Bacteria and Archaea.

What cell characteristic distinguishes Eukarya from Bacteria and Archaea?

Presence of a nucleus and other internal compartments.

What taxonomic system gives every species a two-word Latin name?

Binomial nomenclature.

In binomial nomenclature, which part of the name is capitalized?

The genus name.

Give the scientific name of the ocellaris clownfish.

Amphiprion ocellaris.

Define science in one sentence.

The observation, identification, experimental investigation, and theoretical explanation of natural phenomena.

Give two common model organisms used in biology.

Examples include E. coli (bacterium) and Drosophila melanogaster (fruit fly).

What is the primary goal of discovery-based science?

To collect and analyze data without a preconceived hypothesis, often revealing new patterns or phenomena.

List the five stages of hypothesis testing.

1) Observation; 2) Hypothesis formation; 3) Experimentation; 4) Data analysis; 5) Acceptance or rejection of hypothesis.

Differentiate between a hypothesis and a theory.

A hypothesis is a testable, proposed explanation for a phenomenon; a theory is a broad explanation supported by extensive evidence and predictive power.

In the maple-leaf example, what variable was manipulated in the experiment?

Length of daily light exposure.

Why must valid experiments be repeatable?

Repeatability ensures results are reliable and not due to random chance.

What gene is defective in most cystic fibrosis patients?

The CFTR gene, which encodes a chloride transporter.

Explain how CFTR malfunction leads to thick mucus.

A faulty chloride transporter causes salt imbalance, altering water movement and producing sticky mucus.

Name two social mechanisms that maintain scientific integrity.

Peer review of papers and collaboration/discussion at scientific meetings.

List three core skills every biologist should develop.

Applying the scientific process, quantitative reasoning, and effective communication/collaboration.

What is a scientific model?

A conceptual, physical, or mathematical representation of a real-world phenomenon used for explanation or prediction.

Give an example of a mechanistic model in biology.

A diagram showing the steps of cellular respiration and how each enzyme functions.

What subatomic particles reside in an atom’s nucleus?

Protons and neutrons.

State the charges of protons, neutrons, and electrons.

Protons: +1; Neutrons: 0; Electrons: –1.

What determines an element’s atomic number?

The number of protons in its nucleus.

How many electrons can the first electron shell hold?

Two.

Why are noble gases like neon chemically unreactive?

They have filled outer (valence) electron shells.

Define isotope.

Atoms of the same element with different numbers of neutrons (different mass numbers).

What is the half-life of 14C?

Approximately 5,370 years.

Which titanium isotope has 22 protons and 26 neutrons?

Titanium-48 (mass number 48).

Distinguish between a molecule and a compound.

A molecule is two or more atoms held together by bonds; a compound is a molecule composed of two or more different elements.

Is H2 considered a molecule, a compound, or both?

A molecule only (not a compound because it has one element).

Define radioisotope.

An unstable isotope that undergoes spontaneous decay, emitting radiation.

What type of scientific approach often discovers new genes, such as CFTR?

Discovery-based science.

Which half-life is longer: cobalt-60 or uranium-238?

Uranium-238 (~4.46 billion years) is longer than cobalt-60 (~5.27 years).

What property of electrons primarily influences how atoms interact?

The number and arrangement of electrons in the outer (valence) shell.

What is the maximum number of electrons the second electron shell can hold?

Eight.

Explain the term ‘mixture’ in chemistry.

Two or more substances that intermingle without forming chemical bonds; component proportions can vary.

Why is chemistry fundamental to biology, as illustrated by the ‘sticky gecko’?

Understanding chemical interactions (e.g., van der Waals forces) explains biological phenomena like gecko adhesion.

Which core concept of biology emphasizes that living systems are interconnected and interacting?

Systems.

Give two attributes required of a scientific theory.

Consistency with vast data and ability to make accurate predictions.

What classroom technique encourages solving biology problems by drawing diagrams?

BioTIPS strategy: Make a drawing.

What kind of model traces biological processes over time?

A temporal model.

Name one benefit of genomics and proteomics comparisons across species.

They illuminate evolutionary history and relatedness among organisms.