Spring Semester Final Study Guide Biology 2026

Flashcards covering genetics, evolution, and ecology units for the Spring Biology 2026 Final Exam.

Mutations

Random changes in DNA.

Law of Dominance

The Mendelian law stating that dominant alleles will always be expressed.

Law of Independent Assortment

A law stating that the inheritance of one trait does not affect the inheritance of another.

Law of Segregation

The law stating that every person possesses $2$ alleles of every trait.

Monohybrid Cross Gamete Production

$4$ gametes are produced from this type of cross.

Dihybrid Cross Gamete Production

$16$ gametes are produced from this type of cross.

Alleles

Different variations of the same geneinherited from both parents ($1$ from each parent).

P1

Refers to the parents in a cross.

F1

Refers to the first offspring in a cross.

Gamete

In humans, this type of cell contains $23$ chromosomes.

Sex-linked genes

Genes located specifically on the X and Y chromosome.

Incomplete Dominance

An inheritance pattern where alleles or traits blend together, such as black skin and white skin resulting in tan skin.

Codominance

An inheritance pattern where both alleles are present, such as human blood types or a fish with both red and blue scales.

Type O Blood

The recessive human blood type.

Type A and B Blood

The dominant human blood types.

Haploid Cells

Sex cells or gametes, such as sperm or egg, containing half the number of chromosomes ($23$ in humans).

Diploid Cells

Body cells, such as skin or hair, containing $46$ chromosomes in humans.

Meiosis

The splitting of a cell to make another cell where chromosomes are pulled apart as new cells form.

Nondisjunction

A phenomenon where chromosomes fail to separate during cell division.

Cloning

A process where the offspring has the exact same DNA as the parent instead of a combination of two parents.

Karyotype

A picture of all of an organism's chromosomes ($46$ in a normal human).

Sickle cell disease

A blood disorder characterized by sickle-shaped blood cells that clot in veins and disrupt blood flow, with symptoms including nausea, dizziness, fatigue, and headaches.

Evidence for Evolution

The four main types are DNA, Fossils, Anatomy, and Geography.

Theory of Evolution

The scientific principle that all things share a common ancestor and change over time through genetic variation and natural selection.

Homologous Structures

Structures with the same physical construction but different functions (e.g., arms of humans, cats, bats, and whales) that indicate divergent evolution and a common ancestor.

Analogous Structures

Structures with the same function but different physical construction (e.g., bird wing vs. insect wing) that indicate convergent evolution and no common ancestor.

Superbugs

Strains of bacteria, viruses, or fungi that have developed resistance to most medications and antibiotics used to treat them.

Vestigial Structures

Parts of an organism's body that no longer serve a purpose, such as the human tailbone and appendix, indicating evolutionary changes.

Natural Selection

A process where organisms with beneficial traits survive longer to reproduce; it acts on the phenotype of an organism.

Fitness

The ability of an organism to survive in its environment.

Species

A group of organisms with similar characteristics that are capable of interbreeding.

Hominins

The group of organisms that originated from Africa.

Mass Extinction

A specific time when multiple different species died out, as opposed to the death of a single species.

Speciation

The process occurring when a population of a single species evolves into separate, distinct species due to behavioral, temporal, or habitual isolation.

Punctuated Equilibrium

An evolutionary process where a long period without change is followed by a sudden large change (e.g., the Cambrian boom).

Phyletic Gradualism

An evolutionary process where small changes occur slowly over time, such as in natural selection.

Albedo

The measure of how much sunlight a surface reflects back into space instead of absorbing it.

High Albedo Example

Ice, which reflects light and does not absorb much heat.

Low Albedo Example

The ocean, which absorbs most heat and does not reflect much light.

Cladogram

A diagram showing the evolutionary relationship between organisms.

Phylogenetic Tree

A complex version of a cladogram that includes the time between evolutionary changes.

Law of Superposition

The principle that older rocks and fossils are located at the bottom while newer ones are closer to the surface.

Erosion

The process where earthen materials are worn down and transported by natural forces like wind, water, or ice.

Weathering

The process where materials are worn down but not transported.

Absolute Dating

A scientific method, such as radiometric dating, used to find the exact age of a rock.

Body Fossils

Fossil types consisting of physical remains such as teeth or bones.

Trace Fossils

Fossil types consisting of signs of life such as footprints or burrows.

Mold and Cast Fossils

Fossils created when organisms leave an impression in sediment.

Chemical Fossils

Fossils involving microscopic organisms like bacteria.

Biodiversity

The variety of species in an ecosystem which makes the system resilient and stable.

Invasive Species

Non-native organisms that are dangerous, adapt easily, and spread rapidly, such as the Golden mussels.

Conduction

Heat transfer occurring through direct physical contact.

Convection

Heat transfer occurring through the physical movement of gases or liquid.

Radiation

Heat transfer occurring through electromagnetic waves without requiring physical contact.

Polar Ice Cap Feedback Mechanism

A cycle where rising temperatures melt ice, exposing the low albedo ocean which absorbs more heat and leads to further melting.