ISCI 1A24 LifeSci Midterm: Evolution, Biodiversity & Psychology

What is Life?

Life is characterized by having DNA (or RNA), the ability to evolve, grow, and reproduce.

How do scientists know and mediate uncertainty?

Scientists know through observation and a repeatable process, mediating uncertainty with replication.

What is the difference between observations and categorizations?

Observations are objective recorded features, while categorizations are subjective groupings based on chosen traits.

What are the principal determinants of whether something is alive?

It has DNA (or RNA), can evolve, and can grow and reproduce.

How do bacteria differ from viruses?

Bacteria are single-celled prokaryotes that can grow and reproduce independently, while viruses require a host to reproduce.

What are the main taxonomic categories for living organisms?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

What is bias in scientific categorization?

Bias is a systematic tilt in how information is collected and interpreted, often reflecting human perspective.

What is a dichotomous key?

A stepwise identification tool using paired choices to lead to an identity.

What are other tools to categorize living things?

Cladograms, phylogenies, microscopy, DNA sequencing, taxonomic hierarchy, and field guides.

What are ways to organize biological systems?

Physiological, population, community, landscape, ecosystem, and evolutionary levels.

Why study biological systems from multiple perspectives?

Different perspectives reveal different patterns and provide a more complete picture of complex systems.

Why are hierarchical arrangements of organization considered erroneous?

They imply a strict ladder of importance and overlook the network of interactions within levels.

What is the standard structure of a scientific study?

Introduction, Methods, Results, Discussion, Conclusion, and Literature cited.

What is a complex system?

A system with many interacting components whose collective behavior cannot be predicted from the parts alone.

What is the significance of replication in scientific studies?

Replication builds confidence in findings by confirming results across independent observations.

What are the limitations of categorization based on visible traits?

They can ignore hidden relatedness and lead to misleading classifications.

What is the role of phylogenies in biology?

Phylogenies show relatedness among organisms based on shared derived traits or DNA.

How do scientists combine studies across levels?

They collaborate across different perspectives due to limitations in time, funding, and expertise.

What are emergent properties in complex systems?

Properties that arise from the interactions of components that cannot be predicted from the individual parts.

What is evolution?

Change in allele frequencies in a population over time.

At what level of biological organization does evolution act?

The population.

What does 'Science is a process' mean?

Ideas are proposed, tested, revised or replaced as evidence accumulates.

What is the most important scientific contribution of Darwin and Wallace?

Independently proposing natural selection as the mechanism that explains how populations change.

What are the two main points from the Origin of Species?

Evidence that existing species are descendants of different, now-extinct ancestral species and natural selection as the mechanism of evolution.

What are the modern postulates of the Theory of Evolution by Natural Selection?

Populations evolve; evolution is change in allele frequencies over time; traits are heritable; natural selection occurs when individuals with certain alleles have higher fitness.

Are all adaptations positive?

No, adaptations can be costly or mismatched when the environment changes.

What is the difference between evolution as fact and as theory?

Fact: organisms descended with modification from common ancestors; Theory: a body of interconnected statements about the causes of what we observe.

Why is evolution considered an integrated science?

It draws evidence from many fields such as paleontology, comparative anatomy, embryology, geology, biogeography, and genetics.

What is a species according to the biological species concept?

A group of naturally interbreeding individuals that produce fertile offspring and are reproductively isolated from other such groups.

What are the four main mechanisms leading to evolution?

Natural selection, genetic drift, gene flow, and mutation.

Why might artificial selection differ from natural selection?

Artificial selection is driven by humans choosing traits for a purpose, while natural selection is driven by environmental fitness.

Why is genetic drift important for conservation?

Drift can lower genetic diversity in small populations, making them less able to adapt.

What are the two mechanisms of speciation?

Allopatric (geographic barrier) and sympatric (within the same area).

What is the difference between genotype and phenotype?

Genotype is the genetic makeup; phenotype is the observable features of the organism.

Why is Hardy-Weinberg considered a null hypothesis?

It predicts allele and genotype frequencies stay constant when there is no selection, drift, gene flow, or mutation.

What is the difference between homozygous and heterozygous?

Homozygous has two identical alleles; heterozygous has two different alleles.

What is an allele?

An allele is a version of a gene.

What does homozygous mean?

Having two copies of the same allele (AA dominant or aa recessive).

What does heterozygous mean?

Having two different alleles (Aa), where the dominant allele is expressed.

What is biodiversity?

The variety of biological entities (genes, species, or habitats) in a defined area or sample.

How is diversity measured?

Diversity is measured with richness (S), evenness, and indices such as Shannon (H′) and Simpson (D).

What is alpha diversity?

Local diversity within one community or site.

What is beta diversity?

Differential diversity between sites or sampling units.

What is gamma diversity?

Regional diversity across a wide range of communities or habitats.

What is species richness?

The number of different species in a given area.

What is species evenness?

How similar the relative abundances of species are in a community.

What is a bioindicator species?

A species whose population fluctuates with measurable environmental change.

What are characteristics of a good bioindicator species?

Sensitive to changes, easy to sample and identify, widespread, and well studied.

How is diversity linked to biological organization?

Diversity exists at genetic, species, and ecosystem levels, and shapes each other.

What is psychology?

The scientific study of human behavior and mental processes.

What problems do psychologists seek to answer?

They study how people detect, interpret, decide, and respond to the world.

How have research methods in psychology changed?

Methods shifted from introspection to objective behavior, then to cognition and modern techniques.

How do research perspectives influence data collection?

Questions asked, sampling, and measurement methods shape results and can introduce bias.

How do evolutionary processes affect human behavior?

Natural selection acts on heritable traits, influencing behavior adaptations.

What are the parts of a neuron?

Dendrites, cell body, axon, myelin sheath, and axon terminals.

How do neurons communicate?

Communication within a neuron is electrical; between neurons, it is chemical.

What is the central nervous system (CNS)?

The brain and spinal cord.

What is the peripheral nervous system (PNS)?

Nerves outside the CNS, including spinal and cranial nerves.

What are the two parts of the autonomic nervous system?

Sympathetic (prepares for emergency) and parasympathetic (calming).

What are the main areas of the brain?

Hindbrain, midbrain, and forebrain.

What does the hindbrain control?

Vital functions, balance, and coordination.

What does the midbrain control?

Reflexes and orienting.

What does the forebrain include?

Thalamus, hypothalamus, limbic system, and cerebral cortex.