FINAL EXAM

What are DNA and RNA

Polymers of nucleotides.

What is a nucleotide composed of?

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

What are the four bases of DNA?

Adenine (A), Cytosine (C), Thymine (T), Guanine (G).

What is the difference between DNA and RNA?

DNA has deoxyribose and thymine; RNA has ribose and uracil.

What is the structure/shape of DNA?

A double helix.

What is the flow of genetic information?

DNA → RNA → Protein.

What is transcription?

The process where DNA is copied into RNA.

What is translation?

The process where RNA is used to build proteins.

What is a mutation?

A change in the nucleotide sequence of DNA.

What is a virus?

A nonliving infectious particle made of a protein coat and genetic material.

What is a prion?

An infectious protein that causes diseases like mad cow disease.

What are restriction enzymes and DNA ligase used for?

They are used in biotechnology to cut and join DNA.

How is forensics used in DNA analysis?

To identify individuals using genetic information.

What is PCR (Polymerase Chain Reaction)?

A method to amplify DNA segments.

What is gel electrophoresis?

A technique to separate DNA by size using an electric field.

Who is Charles Darwin and who contributed to his theory?

The scientist who proposed the theory of evolution by natural selection and Alfred Russel Wallace contributed to the theory.

What are fossils?

Fossils are preserved remains or traces of organisms from the past, often found in sedimentary rock.

What is the fossil record?

The fossil record is the collection of all known fossils and their placement in rock layers, showing a timeline of life on Earth.

How does the fossil record support the theory of evolution?

It shows how species have changed over time and reveals transitional forms linking modern organisms to their ancestors.

What is the mechanism of evolution?

Natural selection.

How does natural selection work in the natural environment?

Individuals with traits better suited to their environment survive and reproduce more, passing those traits on to the next generation.

What is homology?

Similar traits inherited from a common ancestor (e.g., human arm and bat wing).

What is a vestigial structure?

A structure with no current function (e.g., appendix in humans).

What does an evolutionary tree represent?

It shows the evolutionary relationships between different species, tracing back to common ancestors.

What do the branch points on an evolutionary tree represent?

Branch points (also called nodes) represent the most recent common ancestor shared by the descendant species.

What are the 3 key points of natural selection?

Variation, inheritance, and differential survival/reproduction.

Example of natural selection?

Insects becoming resistant to pesticides.

What are the 3 random components of sexual reproduction?

Crossing over, independent assortment, and random fertilization.

What is a population?

A group of the same species in the same area.

What is a gene pool?

All the alleles in a population.

What is microevolution?

Small changes in allele frequency in a population over time.

What is the Hardy-Weinberg equation?

A formula used to study genetic variation in a population.

What 5 conditions must be met for Hardy-Weinberg equilibrium?

No mutation, random mating, no gene flow, large population, no selection.

How do you calculate allele frequencies?

Dividing the number of times an allele appears by the total number of alleles at that specific genetic locus in the population. (equation p² + 2pq + q² = 1)

What are the 3 main causes of evolutionary change?

Genetic drift, gene flow, natural selection.

What is the bottleneck effect?

A sharp reduction in population size that reduces genetic diversity.

What is the founder effect?

Reduced genetic variation when a small group starts a new population.

What is relative fitness?

How well an organism can survive and reproduce compared to others.

How old is the Earth?

About 4.6 billion years old.

What is macroevolution?

Major evolutionary changes over long periods.

When did life on Earth first emerge and what was it?

About 3.5 to 4 billion years ago, likely as simple prokaryotic cells.

What is plate tectonics?

Plate tectonics is the theory that Earth’s outer shell is divided into large plates that move over the mantle.

How do plate tectonics affect the movement of continents?

As the plates shift, they carry continents with them, causing them to move, collide, or break apart over millions of years—this movement can lead to changes in climate, habitats, and the isolation of species, which contributes to evolution.

What does the fossil record show?

A timeline of life and evolutionary changes.

How does the fossil record document the history of life?

The fossil record shows the appearance, extinction, and gradual changes of species over time, providing a timeline of life on Earth and evidence for how organisms have evolved.

How many mass extinctions have occurred?

Five major ones in the past.

What is adaptive radiation?

Adaptive radiation is when one species evolves into many different species that adapt to various environments.

What is an example of adaptive radiation?

Darwin’s finches on the Galápagos Islands—one ancestral species evolved into multiple species with different beak shapes and sizes suited to different food sources.

What is the difference between prokaryotes and eukaryotes?

Prokaryotes lack a nucleus; eukaryotes have a nucleus.

What are the two kinds of prokaryotes?

Bacteria and Archaea.

What are the three common prokaryote shapes?

Cocci (spherical), bacilli (rod), spirilla (spiral).

What is a protist?

A protist is a mostly single-celled organism.

What is an example of a protist?

Amoeba—a single-celled organism

How do protists get food?

Through photosynthesis, ingestion, or absorption.

What is mycorrhiza?

A symbiotic relationship between fungi and plant roots.

Who are the ancestors of land plants?

Green algae.

How did plants evolve to exist on land?

By developing features like cuticles, stomata, and vascular tissue.

When did land plants first appear?

Around 470 million years ago.

What is a gymnosperm?

A non-flowering seed plant (e.g., pine trees).

What is an angiosperm?

A flowering plant that produces seeds within fruit. (e.g., rose plant).

What are the parts of a flower?

Sepals, petals, stamens, carpels.

What is a fruit?

A mature ovary that contains seeds.