BIOL 1100 - Exam 4 flashcards

What are analogous characters?

______ are traits that have similar functions in different species but evolved independently, indicating convergent evolution.

What is macroevolution?

______ refers to large-scale evolutionary changes that occur over long periods of time, resulting in the emergence of new species.

What are the key mechanisms of macroevolution?

speciation, genetic drift, gene flow, and large-scale environmental changes.

What is speciation?

_____ is the process by which populations evolve to become distinct species, often due to reproductive isolation.

What is adaptive radiation?

______ is the rapid diversification of a species into a variety of forms to adapt to different environments.

What role does extinction play in macroevolution?

Way for new species to evolve; it opens up ecological niches and promotes biodiversity.

What is the significance of fossil records in macroevolution?

Fossil records provide evidence of past life forms and help trace the evolution of species over time.

How does continental drift relate to macroevolution?

Influence species distribution and promote speciation through geographic isolation.

What are mass extinctions?

_____ are events where a significant percentage of species is wiped out, leading to rapid changes in biodiversity.

What is the difference between microevolution and macroevolution?

______ involves small evolutionary changes within a species, while ______ encompasses larger evolutionary changes that result in new species.

What is convergent evolution?

_____ occurs when unrelated species evolve similar traits due to similar environmental pressures.

What is gene expression?

_______ is the process by which the information from a gene is used to synthesize functional gene products, typically proteins, which perform essential functions in a cell.

What is gene expression?

______ is the process by which information from a gene is utilized to synthesize functional products, such as proteins.

What are the two main stages of gene expression?

transcription and translation.

What occurs during transcription?

During _______, the DNA sequence of a gene is copied to produce a complementary RNA strand.

What is the role of mRNA in gene expression?

To carry the genetic information from DNA to the ribosome, where protein synthesis occurs.

What is translation?

_______ is the process by which ribosomes build proteins based on the sequence of codons in mRNA.

What are codons?

______ are sequences of three nucleotides in mRNA that correspond to specific amino acids.

What is the role of tRNA in translation?

To bring amino acids to the ribosome and matches them to the appropriate codons in mRNA.

What is a promoter?

A ______ is a DNA sequence where RNA polymerase binds to initiate transcription.

What factors can influence gene expression?

Transcription factors, environmental signals, and epigenetic modifications.

What are enhancers and silencers?

________ are DNA sequences that increase transcription levels, while _______ decrease transcription levels.

What are analogous characters?

______ are traits that have similar functions in different species but evolved independently, indicating convergent evolution.

What is post-translational modification?

_______ ________ involves chemical changes to a protein after synthesis, affecting its function and activity.

What is the importance of ribosomes in gene expression?

_______ are the cellular machinery responsible for translating mRNA into protein.

How does gene expression vary between different cell types?

Different sets of genes, leading to diverse functions and characteristics.

What is the central dogma of molecular biology?

The _______ states that genetic information flows from DNA to RNA (transcription) and from RNA to protein (translation).

What is the significance of regulatory RNA molecules?

________, such as microRNAs and long non-coding RNAs, play roles in gene regulation and can modulate gene expression.

What role do transcription factors play in gene expression?

_________ are proteins that bind to specific DNA sequences to promote or inhibit transcription.

What is the function of RNA Polymerase?

______ is the enzyme that synthesizes RNA from a DNA template during transcription.

How can mutations affect gene expression?

_____ can alter the DNA sequence, potentially affecting transcription and translation processes, which may lead to changes in protein function.

What is chromatin remodeling?

_______ refers to the dynamic alteration of chromatin structure to allow access to DNA for transcription and replication.

What is evolution?

_______ is the change in the heritable characteristics of biological populations over successive generations.

What is natural selection?

________ is the process where organisms better adapted to their environment tend to survive and produce more offspring.

Who proposed the theory of evolution by natural selection?

_______ proposed the theory of evolution by natural selection.

What is genetic variation?

________ is the diversity in gene frequencies within a population.

What is a mutation?

A ______ is a change in the DNA sequence that can lead to new traits.

What is a species?

A _____ is a group of organisms that can interbreed and produce fertile offspring.

What is adaptation?

_____ is a characteristic that enhances an organism's ability to survive and reproduce in its environment.

What is artificial selection?

____________ is the intentional breeding of organisms with desirable traits.

What are homologous structures?

_________ are body parts that are similar in structure but different in function, indicating common ancestry.

What are analogous structures?

_______ are body parts that have similar functions but different evolutionary origins.

What is speciation?

________ is the process through which new species arise from existing species.

What is the Hardy-Weinberg equilibrium?

The ________ _________ conditions describe a stable, non-evolving population where allele frequencies remain constant.

What is genetic drift?

________ is the random fluctuation of allele frequencies in a population, which can lead to significant changes over time.

What is the role of fossils in evolution?

provide evidence of past life forms and evolutionary transitions between species.

What is convergent evolution?

_______ is when unrelated species develop similar traits due to similar environmental pressures.

What is the significance of transitional fossils?

______ fossils show intermediate traits between different groups, supporting the theory of evolution.

What is the modern synthesis of evolution?

The ______ combines Darwin's theory of natural selection with Mendelian genetics.

What is a common ancestor?

A ________ is an ancient species from which two or more species have evolved.

What are reproductive barriers?

______ _____ are mechanisms that prevent different species from interbreeding.

What is taxonomy?

_____ is the science of classifying and naming organisms.

What is biogeography?

Biogeography is the study of the distribution of species and ecosystems in geographic space and time.

What is population genetics?

_______ is the study of the distribution and change in frequency of alleles within populations.

What is an allele?

An _______ is a variant form of a gene that may produce distinguishable phenotypic effects.

What is gene frequency?

______ refers to how often a particular allele appears in a population.

What is a genotype?

A _______ is the genetic constitution of an individual, represented by the alleles it possesses.

What is a phenotype?

A ______ is the observable physical or biochemical characteristics of an organism, determined by its genotype.

What is inbreeding?

_______ is the mating of closely related individuals, which can increase the chance of offspring inheriting genetic disorders.

What is outbreeding?

_______ is the mating of individuals from different populations, which can increase genetic diversity.

What is genetic drift?

____ is the change in the frequency of an allele in a population due to random sampling of organisms.

What is a founder effect?

The _______ occurs when a small group from a larger population establishes a new population, leading to reduced genetic variation.

What is a bottleneck effect?

The ______ occurs when a population's size is dramatically reduced, leading to loss of genetic diversity.

What is gene flow?

________ is the transfer of genetic material between populations, which can increase genetic diversity.

What is natural selection?

_______ is the process in which organisms better adapted to their environment tend to survive and reproduce.

What is stabilizing selection?

_______ favors intermediate variants and acts against extreme phenotypes.

What is directional selection?

_________ occurs when one extreme phenotype is favored over others, causing the allele frequency to shift.

What is disruptive selection?

________ favors individuals at both extremes of a trait, leading to two or more contrasting phenotypes.

What is phylogeny?

_______ is the study of the evolutionary history and relationships among individuals or groups of organisms.

What is a phylogenetic tree?

A ________ is a diagram that represents evolutionary relationships among various biological species based on similarities and differences in their genetic or physical traits.

What does a node represent in a phylogenetic tree?

A ____ represents a common ancestor of the descendants branching from that node.

What is a clade?

A ___ is a group of organisms that include an ancestor and all its descendants.

What is the difference between homologous and analogous structures?

_______ structures are similar due to shared ancestry, while _________ structures serve similar functions but do not share a recent common ancestor.

What is molecular phylogenetics?

________ is the analysis of molecular data, typically DNA or protein sequences, to infer evolutionary relationships.

What is a sister taxa?

_______ are groups of organisms that are each other's closest relatives on a phylogenetic tree.

What is cladistics?

______ is a method of classifying organisms based on shared derived characteristics and the branching patterns of evolution.

What is a shared ancestor?

A _____ ______ is a common ancestor from which two or more descendant species evolved.

What is parsimony in phylogenetics?

________ is a principle that suggests the simplest explanation or path of evolution with the least number of changes is preferred.

What are morphological traits?

_________ ______ are structural features of organisms, such as shape, size, and form, often used in phylogenetic analysis.

What role does genetic data play in phylogeny?

__________ provides insights into evolutionary relationships by showing similarities and differences at the molecular level.

What is an outgroup?

An ________ is a species or group that is closely related but not part of the group being studied, used for comparison.

What is a taxonomic hierarchy?

A ___________ is a system of classification that arranges organisms in a ranked order, from broad to specific categories (e.g., domain, kingdom, phylum).

What is endemism?

________ refers to a species that is native to and restricted to a particular geographical area.

What is speciation?

_________ is the evolutionary process by which populations evolve to become distinct species.

What are the two main types of speciation?

allopatric speciation and sympatric speciation.

What is allopatric speciation?

_______ occurs when a population is geographically isolated, leading to the evolution of new species.

What is sympatric speciation?

_____ occurs when new species arise from a single population without geographic isolation, often through mechanisms like polyploidy or habitat differentiation.

What are analogous characters?

______ are traits that have similar functions in different species but evolved independently, indicating convergent evolution.

What role does reproductive isolation play in speciation?

_______ prevents interbreeding between populations, allowing them to evolve into separate species.

What are prezygotic barriers?

______ barriers are mechanisms that prevent mating or fertilization between different species.

What are postzygotic barriers?

_______ barriers occur after fertilization and reduce the viability or reproductive capacity of hybrid offspring.

What is temporal isolation?

_______ occurs when species breed at different times, preventing mating.

What is behavioral isolation?

_________ occurs when differences in mating behaviors prevent interbreeding between populations.

What is mechanical isolation?

________ occurs when structural differences in reproductive organs prevent mating.

What is habitat isolation?

_______ occurs when species occupy different habitats and rarely meet, thus preventing mating.

What is gametic isolation?

________ occurs when sperm and eggs of different species are incompatible and cannot fertilize.

What is hybrid inviability?

______ occurs when hybrid offspring fail to develop properly and do not survive to maturity.

What is hybrid sterility?

______ happens when hybrid offspring are sterile and cannot reproduce, like mules.

What is the biological species concept?

The _______ defines a species as a group of populations that can interbreed and produce viable, fertile offspring.

What is the phylogenetic species concept?

The ________ defines a species based on its unique evolutionary history and genetic makeup.