JS BIO Questionnaires Flashcards
Identify the term used to describe the consistent biochemical structures shared by all living organisms.
A) Unity - Diversity Paradox
B) Conservation of critical genetic sequences
C) Unity of Biochemical Structures
D) Unique Assembly of Parts
A. Unity of biochemical structures
What questions how life can be both unified and highly diverse?
A) Unity of Biochemical Structures
B) Allozyme
C) Unity - Diversity Paradox
D) Unique Assembly of Parts
B. Unity-Diversity Paradox
A fish species is found to have an enzyme that binds its substrate less tightly in cold water but functions optimally at very low temperatures. Which adaptation mechanism does this demonstrate?
A) Gene amplification for increased enzyme production
B) Selection for regulatory alleles controlling enzyme timing
C) Temperature optimization balancing enzyme stability and efficiency
D) RNA translation accuracy balancing energy costs
C) Temperature optimization balancing enzyme stability and efficiency
Insect populations exposed to pesticides show resistance that persists even when pesticides are no longer used. This likely reflects:
A) Random mutations accumulating over generations B) Gene amplification enhancing detoxifying enzyme production C) Regulatory alleles that quickly reverse resistance when pressure is removed D) Decreased catalytic efficiency to conserve energy
B) Gene amplification enhancing detoxifying enzyme production
Which of the following best describes the role of natural selection in biochemical adaptation?
A. Natural selection does not contribute to biochemical adaptation and instead relies on mutation
B. Natural selection drives the adaptation of biochemical systems to fit environmental demands by favoring advantageous alleles
C. Natural selection only affects structural proteins, leaving regulatory proteins unchanged
D. Biochemical adaptation occurs randomly and is independent of natural selection
B) Natural selection drives the adaptation of biochemical systems to fit environmental demands by favoring advantageous alleles
Which of the following examples below provides direct evidence of natural selection leading to biochemical adaptation?
A. Seasonal changes in enzyme levels in organisms with no change in function
B. The acquisition of antibiotic resistance in bacteria through random mutation
C. the neutral drift of amino acids in proteins with no effect on enzyme function.
D. Selection for allozymes that modify enzyme interactions with insecticides, improving survival rates in insects
D) Selection for allozymes that modify enzyme interactions with insecticides, improving survival rates in insects
Which of the following is the primary mechanism responsible for the conservation of critical sequences in DNA?
A) Differential Repair Efficiency
B) Stabilizing Selection by Natural Selection
C) Enhancer Sequences
D) Transcriptional Regulation
B) Stabilizing Selection by Natural Selection
Which of the following mechanisms is primarily responsible for the creation of diversity through the principle of unique assembly?
A) DNA Replication
B) Gene Mutation
C) Gene Regulation and the timing/location of gene expression
D) Chromosomal Rearrangement
C) Gene Regulation and the timing/location of gene expression
Which of the following scenarios best exemplifies a potential mechanism for genetic innovation that combines both internal genomic changes and external influences?
A) The emergence of novel metabolic pathways in molluscs due to a series of chromosomal deletions followed by the acquisition of plasmid DNA from a soil bacterium.
B) The development of new protein functions solely through point mutations in regulatory genes without any external genetic contributions.
C) The evolution of lactate dehydrogenase analogs in marine invertebrates exclusively through gene duplication events within their ancestral genomes.
D) The adaptation of anaerobic glycolysis in terrestrial vertebrates through environmental pressures leading to widespread horizontal gene transfer from marine organisms.
A) The emergence of novel metabolic pathways in mollusc due to a series of chromosomal deletions followed by the acquisition of plasmid DNA from a soil bacterium.
In the context of genetic innovation, which of the following statements most accurately describes the role of chromosomal restructuring and horizontal gene transfer as mechanisms for developing new gene products?
A) Chromosomal restructuring, such as deletions and amplifications, is the primary mechanism for generating new genes, while horizontal gene transfer merely serves as a secondary source of genetic material that does not contribute to functional innovation.
B) Both chromosomal restructuring and horizontal gene transfer can lead to the emergence of novel genes; however, chromosomal changes typically result in modifications of existing functions, whereas horizontal gene transfer introduces entirely new functions that were previously absent.
C) Horizontal gene transfer is exclusively responsible for creating new enzymatic functions in marine invertebrates, while chromosomal restructuring has no significant impact on metabolic pathways.
D) Chromosomal restructuring is limited to regulatory genes, whereas horizontal gene transfer can affect both structural and regulatory genes, leading to a broader spectrum of functional innovations.
B) Both chromosomal restructuring and horizontal gene transfer can lead to the emergence of novel genes; however, chromosomal changes typically result in modifications of existing functions, whereas horizontal gene transfer introduces entirely new functions that were previously absent.
What is the process called that describes changes in the inherited characteristics of biological populations over successive generations?
Mutation
Evolution
Adaptation
Speciation
b) Evolution
Evolution is defined as the process of change in inherited characteristics across successive generations. This question assesses the understanding of evolution as a population-wide process, not merely individual changes.
Which of the following is not an example of Phyletic Evolution?
A. The evolution of modern horses from their small, multi-toed ancestors over millions of years, adapting to changing environments and diets.
B. The gradual transformation of whales from land-dwelling mammals to fully aquatic creatures, showcasing adaptations like streamlined bodies and loss of hind limbs.
C. The divergence of different finch species on the Galápagos Islands due to geographic isolation, leading to the development of distinct traits based on their specific environments.
D. The evolution of elephants from smaller, forest-dwelling ancestors into larger, tusked animals adapted to a variety of environments, including savannas and grasslands.
C. The divergence of different finch species on the Galápagos Islands due to geographic isolation, leading to the development of distinct traits based on their specific environments.
Phyletic evolution, or anagenesis, refers to the gradual transformation of a single lineage over time, resulting in a new form without branching into multiple species. In this process, one species gradually changes into another without splitting into distinct species.
The example of finch species diverging on the Galápagos Islands represents cladogenesis, or branching evolution, where a single species splits into multiple species due to geographic isolation and adaptation to different environments. This is distinct from phyletic evolution, where a single species gradually transforms over time without forming new branches.
Which of these scenarios best illustrates convergent evolution?
Wolves and hyenas developing similar hunting strategies due to their environments, despite being distantly related.
A population of butterflies evolving colorful patterns as a warning signal to predators.
Two species of squirrels evolving different fur colors on separate islands due to varying climates.
A species of lizard evolving longer legs to escape predators faster.
Wolves and hyenas developing similar hunting strategies due to their environments, despite being distantly related,” as convergent evolution involves different species independently evolving similar traits due to similar environmental pressures.
What occurs during recombination?
a) Random distribution of chromosomes into gametes
b) Exchange of genetic material between homologous chromosomes
c) Separation of sister chromatids
d) Replication of DNA
b) Exchange of genetic material between homologous chromosomes
During recombination, homologous chromosomes exchange genetic material, which increases genetic diversity in gametes. This process occurs during meiosis and results in new combinations of alleles on each chromosome.
In areas where malaria is prevalent, individuals with which genotype have a survival advantage due to heterozygote superiority?
A. Homozygous dominant for the normal hemoglobin allele
B. Homozygous recessive for the sickle-cell allele
C. Heterozygous for the sickle-cell and normal hemoglobin alleles
D. Homozygous for the sickle-cell allele
C. Heterozygous for the sickle-cell and normal hemoglobin alleles
In malaria-prone areas, individuals with one sickle-cell allele and one normal hemoglobin allele (heterozygotes) have a survival advantage. This is known as heterozygote superiority or heterozygote advantage, as it provides some resistance to malaria without causing full sickle-cell disease.
Which of the following describes the principle that allele and genotype frequencies remain stable in a large, randomly mating population without evolutionary influences?
A. Heterozygote superiority
B. Diversifying selection
C. Hardy-Weinberg equilibrium
D. Frequency-dependent selection
C. Hardy-Weinberg equilibrium
The Hardy-Weinberg equilibrium describes a principle in population genetics stating that allele and genotype frequencies remain constant in a large, randomly mating population in the absence of evolutionary influences such as selection, mutation, migration, or genetic drift.
What happens to traits that are disadvantageous to an organism’s survival and reproduction in the process of natural selection?
a) They are more likely to be passed on to the next generation.
b) They are adopted into the population.
c) They are gradually discarded over time.
d) They lead to an increase in population size.
c) They are gradually discarded over time.
In natural selection, traits that hinder an organism’s survival or reproduction are less likely to be passed onto future generations. Over time, this reduces the frequency of disadvantageous traits in the population.
Which of the following is an example of a prezygotic isolating mechanism?
A. Mules being sterile hybrid offspring of horses and donkeys
B. Two species of frogs breeding at different times of the year
C. Hybrid plants that are less vigorous than their parent species
D. A species of plant that does not produce viable seed when cross-pollinated with another species
B. Two species of frogs breeding at different times of the year
Prezygotic isolating mechanisms prevent mating or fertilization between species before a zygote is formed. In this example, the two species of frogs breed at different times (temporal isolation), which prevents them from mating and producing offspring. The other options describe postzygotic mechanisms, which occur after fertilization.
Which mechanism of evolution allows individuals with advantageous traits to survive and reproduce more successfully in their environment?
a) Genetic drift
b) Gene flow
c) Natural selection
d) Mutation
c) Natural selection
Natural selection is the mechanism through which individuals with traits that offer survival or reproductive advantages are more likely to thrive and reproduce. This leads to the gradual increase of those advantageous traits in a population over time, making it a primary driver of evolution.
