Biology Final Exam Spring 2025 Review

Flashcards for Biology Final Exam Review

What is Polymorphism?

The existence of multiple distinct forms of a specific DNA sequence that can occur among different individuals or populations

What is an Allele?

A variation or version of a specific gene (e.g., eye color, hair color)

What is a Genome?

An organism's complete set of genetic information

What is Allele Frequency?

Proportion of chromosomes in a population that carry a particular allele

What is Genotype Frequency?

Proportion of individuals in a population that carry a particular genotype

What is Hardy-Weinberg Equilibrium?

A way to calculate expected genotype frequencies from allele frequencies, assuming evolution is NOT occurring (p2 + 2pq + q2 = 1)

What is Genetic Drift?

Random fluctuation of allele frequencies within a population, especially in smaller populations, due to chance events

What is the Bottleneck Effect?

A significant reduction in a population's size due to a catastrophic event, leading to a loss of genetic diversity

What is the Founder Effect?

A reduction in genetic variability that occurs when a small group of individuals from a larger population migrates and establishes a new, isolated population.

What are Species Concepts?

Rules used to draw lines between species.

What is the key factor in the Biological Species Concept?

Reproductive isolation

What is the key factor in the Evolutionary Lineage Species Concept?

Common evolutionary traits and homologies

What is the key factor in the Ecological Species Concept?

Specific use of environmental resources and niches

What is the key factor in the General Lineage Species Concept?

Holistic, based on all of the above

What is Allopatric Speciation?

An event where two species form as a result of a geographic separation between the members of a population

What is Sympatric Speciation?

Occurs within a population without a geographic separation

What is Gradualism?

Speciation that occurs as a result of the accumulation of many insignificant mutations

What is Punctuated Equilibrium?

Speciation that occurs as the result of very few significant mutations

What is Reproductive Isolation?

The inability of two organisms of different species to reproduce in the long term

What is Prezygotic Isolation?

The inability of two organisms to mate

What is Postzygotic Isolation?

The inviability of hybrid organisms post-fertilization

What is Allopatric Isolation?

he two organisms are in different geographical locations

What is Temporal Isolation?

The two organisms are not active during the same time of day to be able to mate

What is Behavioral Isolation?

The two organisms do not share the correct behaviors or mating rituals to be able to mate

What is Mechanical Isolation?

A physical inability to mate based on the two organisms' genitalia

What is Gamete Isolation?

The two gametes are unable to fuse and produce a zygote

What is Hybrid Inviability?

A zygote forms, but cannot fully grow into an organism

What is Hybrid Sterility?

A hybrid forms, but is sterile

What is Hybrid Breakdown?

A hybrid forms and is sterile, but the accumulation of incorrect amounts of genetic material prevents the long-term reproduction of hybrids

What is Binomial Nomenclature?

The scientific name of a species with its genus

What is the order of taxonomic classification?

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species

What is Systematics?

The study of the relationships between species

What is Phylogeny?

The evolutionary relationships between species

What is an Ingroup?

A group of organisms that are evolutionarily related

What is an Outgroup?

An organism that is relatively unrelated to the ingroup

What are Evolutionary Trees?

Trees are used to represent evolutionary relationships between organisms and The intersection of a tree represents ancestral organisms that are no longer seen in modern times

What is Parsimony?

The idea that trees should be drawn to reflect the most likely evolutionary relationships

What is Monophyly?

A group of organisms that includes all descendants of a common ancestor

What is Paraphyly?

A group of organisms that includes a common ancestor but not all of its descendants

What is Polyphyly?

A group of organisms that do not share a recent common ancestor, meaning that they have evolved independently from multiple lineages

What is Altruism?

The choice of an organism to provide some benefit for another organism at its expense

What is Kin Selection?

Possible explanation for altruism

What is Hamilton's Rule?

rb > c; A way to predict whether or not an individual will perform an altruistic act

What is Habituation?

An organism learns to ignore a repeated stimulus

What is Classical Conditioning?

An involuntary response comes to be associated with a stimulus

What is Operant Conditioning (or trial and error learning)?

An animal's behavior is reinforced by a consequence, either a reward or a punishment

What is Cognitive Learning?

The ability to solve problems with conscious thought and includes activities such as perception, analysis, judgment, recollection, and imagining

What is a Hypothesis?

An idea based on observations and/or experiments that gives a possible explanation for an observed natural phenomenon

What is a Theory?

Broad explanation for the natural phenomenon that is supported by large amounts of evidence

What does it mean to be Falsifiable?

When something CAN be shown to be incorrect after further investigation, observation, or experimentation

What are some characteristics of Science?

Self-correcting, expects repeatability of study results, evidence-based, subject to ethical limits as determined by society

What are core concepts of science stated in the lecture?

Evolution, Structure and function

What is Evolution?

A heritable change in a population of organisms from one generation to the next

What are the requirements for Natural Selection?

variation, heritability, Differences in reproductive success and survival

What other factors influence evolutionary change?

Mutation (source), Genetic drift, Non-random mating, gene flow (migration)

What is the Law of Segregation?

Homologous chromosome pairs separate into different daughter cells

What is the Law of Independent Assortment?

The alleles of two (or more) different genes get sorted into gametes independently. Assumes equal numbers of non-recombinant (no crossing over needed) and recombinant (crossing over needed) games

What is Linkage?

genes are located close together on the same chromosome they tend to assort more frequently together as crossing over events between are less likely to occur

What is Aneuploidy?

An abnormal number of chromosomes in a cell. Ex: Trisomy 21

What is Polyploidy?

Extra complete sets of chromosomes. Ex: Triploid plants with 36 instead of 12

What are Nucleic acids responsible for?

Responsible for the storage and transmission of genetic information: 5 ’ pentose sugar (ribos vs. deoxyribose), string of phosphates and Nitrogenous bases: A, T, G, C, U

What are Carbohydrates mostly used for?

Quick source of energy Also sometimes used for maintaining cell structure

What are Lipids mostly used for?

Molecules that can store A LOT of energy Also needed for membrane structure

What is Transcription?

Converting DNA into RNA

What occurs during the Initiation phase of Transcription?

Sigma factor binds (prokaryotes) or transcription factor binds (eukaryotes)

What occurs during the Elongation phase of Transcription?

RNA polymerase synthesizes 5’ to 3’

What occurs during the Termination phase of Transcription?

Terminator sequence signals that transcription is complete

What is Splicing?

Removal of introns

What is the purpose of Addition of 5’ cap?

Prevents mRNA degradation in the cytosol helps bind to the ribosome

What is the purpose of Addition of Poly-A-tail?

Stabilizes mRNA in the cytosol Helps export mRNA out of the nucleus

How does transcription and translation differ in prokaryotes?

Transcription and translation occur simultaneously in the cytoplasm

What is Translation?

Production of a protein from an mRNA transcript

What occurs at the A Site?

where the tRNA comes in

What occurs at the P site?

where the protein is

What occurs at the E site?

where tRNA exists

What are the four steps of translation?

The ribosome binds to the 5’ cap and moves along the start codon, Amino acids are added one at a time (read 5’ → 3’), Protein is made from N → C terminus, and Release factor binds to the stop codon, finalizing translation

What are the 3 potential results of CRISPR/Cas9?

The cut is repaired by introducing a mutation in the DNA, Enzymes are engineered to make cuts on either side of the target DNA to remove the target DNA and rejoin ends, and The DNA repair system can be hijacked to insert a section of DNA into the genome

What occurs at Non-homologous end joining (NHEJ)?

DBS is fixed by simply rejoining the two sides of the break together

What occurs at Homologous recombination (HR)?

DSB is fixed by looking for a template that is homologous to the break

What is the job of the Repressor?

binds to operator repressing the expression of the lac operon.

What is the job of the Activator (CAP)?

cAMP is produced in high amounts when glucose is low, then cAMP binds to CAP allowing it to bind to the activator site, increasing transcription

How is Gene Regulation controlled in Eukaryotes?

Chromatin compaction using histones, histone modification (Methylation and Acetylation), Alternative splicing, and Euchromatin vs Meterochromatin

Why is Gene Regulation important?

Energy saving, Cell differentiation, and Developmental differences