Podcast
Questions and Answers
What is the smallest unit that can evolve over time?
What is the smallest unit that can evolve over time?
What does 'natural selection' act directly on?
What does 'natural selection' act directly on?
What is the relationship between genotype and phenotype?
What is the relationship between genotype and phenotype?
Which of the following is NOT a component of Darwinian evolution?
Which of the following is NOT a component of Darwinian evolution?
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What is the relationship between microevolution and macroevolution?
What is the relationship between microevolution and macroevolution?
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Why does a species need to adapt to change?
Why does a species need to adapt to change?
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In the context of Darwinian evolution, the term 'fitness' refers to:
In the context of Darwinian evolution, the term 'fitness' refers to:
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Why is the vastness of evolutionary time important for understanding macroevolution?
Why is the vastness of evolutionary time important for understanding macroevolution?
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What is the approximate size of a strand of human hair in micrometers?
What is the approximate size of a strand of human hair in micrometers?
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What is the primary reason for studying cells?
What is the primary reason for studying cells?
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Which of the following is NOT a basic feature of ALL cells?
Which of the following is NOT a basic feature of ALL cells?
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What is the primary function of ribosomes within a cell?
What is the primary function of ribosomes within a cell?
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What is the unit of measure used to describe the size of atoms and bond lengths?
What is the unit of measure used to describe the size of atoms and bond lengths?
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How many micrometers are there in one meter?
How many micrometers are there in one meter?
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What is the approximate range of wavelengths for visible light?
What is the approximate range of wavelengths for visible light?
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According to the content, what is the main unifying theme in biology, alongside cell theory?
According to the content, what is the main unifying theme in biology, alongside cell theory?
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Which of the following is NOT a class of biological macromolecules found in living things?
Which of the following is NOT a class of biological macromolecules found in living things?
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What is the main difference between prokaryotes and eukaryotes?
What is the main difference between prokaryotes and eukaryotes?
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What is the significance of the RNA world hypothesis?
What is the significance of the RNA world hypothesis?
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What is the role of liposomes in protocell formation?
What is the role of liposomes in protocell formation?
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Which of the following events is NOT a major step in the evolution of cells?
Which of the following events is NOT a major step in the evolution of cells?
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What event is believed to have led to the evolution of eukaryotic cells?
What event is believed to have led to the evolution of eukaryotic cells?
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Which of the following correctly describes the order of the major events in the evolution of cells?
Which of the following correctly describes the order of the major events in the evolution of cells?
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Which of the following biochemical processes evolved during the time when prokaryotes were the dominant form of life?
Which of the following biochemical processes evolved during the time when prokaryotes were the dominant form of life?
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Which of the following is NOT a major unifying concept of biology as presented in the content?
Which of the following is NOT a major unifying concept of biology as presented in the content?
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According to the content, how does the everyday use of the word "theory" differ from its scientific meaning?
According to the content, how does the everyday use of the word "theory" differ from its scientific meaning?
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Which of the following is NOT a part of the Modern Cell Theory as presented in the content?
Which of the following is NOT a part of the Modern Cell Theory as presented in the content?
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How does the content describe the relationship between all species?
How does the content describe the relationship between all species?
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What is the mechanism by which the characteristics of a population change over time, according to the Theory of Evolution by Natural Selection?
What is the mechanism by which the characteristics of a population change over time, according to the Theory of Evolution by Natural Selection?
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What is the main advantage of eukaryotic cells over prokaryotic cells?
What is the main advantage of eukaryotic cells over prokaryotic cells?
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Which of the following is NOT mentioned in the content as a unifying concept related to cells?
Which of the following is NOT mentioned in the content as a unifying concept related to cells?
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How does the content explain the relationship between cells in a multicellular organism?
How does the content explain the relationship between cells in a multicellular organism?
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What is the primary role of endosymbiosis in the evolution of cells?
What is the primary role of endosymbiosis in the evolution of cells?
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Which of the following is NOT a significant advantage offered by multicellular organisms?
Which of the following is NOT a significant advantage offered by multicellular organisms?
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What is the primary significance of the statement that "All organisms are made from cells" as highlighted in the content?
What is the primary significance of the statement that "All organisms are made from cells" as highlighted in the content?
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What is the significance of the "Cambrian Explosion" in relation to multicellularity?
What is the significance of the "Cambrian Explosion" in relation to multicellularity?
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Which statement about the timeline of evolution of cells is accurate?
Which statement about the timeline of evolution of cells is accurate?
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What is the primary reason for the increased complexity of eukaryotic cells compared to prokaryotic cells?
What is the primary reason for the increased complexity of eukaryotic cells compared to prokaryotic cells?
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Which of these is NOT a direct consequence of the evolution of multicellularity?
Which of these is NOT a direct consequence of the evolution of multicellularity?
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What is the BEST explanation for why Simon Conway Morris describes the eukaryotic cell as "evolution's major achievement"?
What is the BEST explanation for why Simon Conway Morris describes the eukaryotic cell as "evolution's major achievement"?
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Which of the following is a correct explanation for the presence of a vestigial hemoglobin gene in icefish?
Which of the following is a correct explanation for the presence of a vestigial hemoglobin gene in icefish?
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What is a vestigial structure?
What is a vestigial structure?
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What evidence supports the fusion of two ancestral chromosomes to form human chromosome 2?
What evidence supports the fusion of two ancestral chromosomes to form human chromosome 2?
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The presence of vestigial structures in organisms provides evidence for which of the following?
The presence of vestigial structures in organisms provides evidence for which of the following?
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What is the most likely reason for the absence of hemoglobin in icefish?
What is the most likely reason for the absence of hemoglobin in icefish?
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The presence of the hemoglobin gene in icefish, despite its non-functionality, can be described as an example of:
The presence of the hemoglobin gene in icefish, despite its non-functionality, can be described as an example of:
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The absence of hemoglobin in icefish is an example of:
The absence of hemoglobin in icefish is an example of:
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Flashcards
Theory of Evolution by Natural Selection
Theory of Evolution by Natural Selection
A scientific explanation that species change over time through natural selection of heritable traits.
Cell Theory
Cell Theory
A fundamental concept stating that all living organisms are composed of cells and that all cells arise from pre-existing cells.
Darwinian Evolution
Darwinian Evolution
The theory that species evolve over time due to natural selection, emphasizing adaptation and survival.
Homeostasis
Homeostasis
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Modern Cell Theory
Modern Cell Theory
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Genetics
Genetics
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Natural Selection
Natural Selection
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Common Ancestor
Common Ancestor
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Shared Chemical Composition
Shared Chemical Composition
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Basic Features of Cells
Basic Features of Cells
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Plasma Membrane
Plasma Membrane
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Cytosol
Cytosol
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Units of Measure: Micrometer
Units of Measure: Micrometer
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Units of Measure: Nanometer
Units of Measure: Nanometer
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Evolution in Biology
Evolution in Biology
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Icefish
Icefish
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Thinner Blood
Thinner Blood
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Vestigial Gene
Vestigial Gene
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Chromosome Count in Apes
Chromosome Count in Apes
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Missing Chromosome Theory
Missing Chromosome Theory
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Fusion of Chromosomes
Fusion of Chromosomes
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Telomeres
Telomeres
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Common Ancestor Evidence
Common Ancestor Evidence
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Population
Population
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Heritable Traits
Heritable Traits
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Phenotype
Phenotype
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Genotype
Genotype
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Macroevolution
Macroevolution
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Climbing Mount Improbable
Climbing Mount Improbable
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Evolutionary Time
Evolutionary Time
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Abiogenesis
Abiogenesis
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Protocells
Protocells
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RNA World
RNA World
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Prokaryotes
Prokaryotes
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Eubacteria
Eubacteria
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Archaea
Archaea
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Endosymbiogenesis
Endosymbiogenesis
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Multicellularity
Multicellularity
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Eukaryotes
Eukaryotes
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Cambrian Explosion
Cambrian Explosion
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Study Notes
Course Information
- Course title: Biology 1 – Cells, Molecular Biology and Genetics
- Course code: Biol 1000
- Professor: Dr. Michael Cardinal-Aucoin
- Semester: Winter 2025
- Institution: York University
Evolution
- Major unifying theories in biology
- Darwinian evolution
- Natural selection
- Evidence and examples of evolution
Unifying Concepts of Biology
- Theory of Evolution by Natural Selection
- Cell Theory
- Genetics
- Homeostasis
Theories in Science
- Everyday use of "theory": a guess, speculation
- Scientific theory: a broad explanation supported by many lines of evidence, aids in creating new hypotheses, withstands scientific scrutiny
Theory of Evolution by Natural Selection
- Characteristics of a population change over time (pattern)
- Individuals with heritable traits produce more offspring than those without (mechanism)
- All species are related through common ancestry
- All species descend from pre-existing species
Cell Theory
- All organisms are made of cells (pattern)
- All cells come from pre-existing cells (mechanism)
- All cells in a multicellular organism descend from an ancestral cell
- All single-celled organisms in a population are related to a common ancestor
Modern Cell Theory
- A cell is the smallest self-reproducing unit of life
- Cells make up all living things
- New cells arise from pre-existing cells
- Organism's activity depends on the total activity of independent cells
- Energy flow (metabolism & biochemistry) occurs within cells
- Cells contain hereditary information (DNA and RNA)
- Cells of similar organisms share similar chemical composition
Cells
- All cells share certain properties but are not identical
- Plant, animal, and bacterial cells are different sizes and structures
Different Types of Cells
- Four basic features of all cells: plasma membrane, semifluid cytosol, genetic material, ribosomes
- Plus metabolism (chemical pathways) to convert various energy forms into biochemical work
Units of Measurement
- Micrometer (µm): 1,000,000 µm = 1 meter; strand of hair ~20-180 µm
- Nanometer (nm): 1,000,000,000 nm = 1 meter; wavelength of visible light ~400-700 nm
- Angstrom (Å): 10,000,000,000 Å = 1 meter; used to measure atomic/bond lengths; C-H bond in methane ~1 Angstrom
Introduction to the Cell
- The human body has ~37 trillion cells
- Cells vary greatly in size, as seen in the graphic
Why Study Cells?
- Cells are the fundamental functional unit of all living things
- Cell theory is a unifying principle in biology
- Understanding cells helps understand how organisms function (plants, animals, parasites, fungus, etc.)
- Crucial for understanding human health & disease
Evolution by Natural Selection
- If a population has differences between individuals that are heritable and result in differential survival and reproduction, then evolution will occur.
- Differences can form from mutations and meiosis in reproduction
Natural Selection
- Natural selection is one mechanism driving evolution
- Artificial and sexual selection, genetic drift, and gene flow are other mechanisms
Evidence for Evolution
- Extensive evidence supports the theory
- Homology, fossil record, genomics, insecticide resistance, genetic, biogeography, micro and macro evolution, anatomical features, comparative biochemistry, and embryology
Darwin's Theory
- Natural selection in action (examples)
- Homology (anatomy, development, molecular)
- Convergent evolution (analogous features)
- Biogeography
- Fossils
Antibiotic Resistance
- Drug use can lead to pathogens becoming drug resistant
- Bacteria and HIV can become drug resistant
Homology: Vestigial Genetic/Molecular
- Analysis of icefish and other species reveals vestigial genes
- Icefish genes lack hemoglobin
- Similar genes and proteins in various organisms support evolutionary links
Convergent Evolution
- Similar traits in unrelated species that adapt to similar environments
- Analogous features demonstrate a shared environmental pressure, not a common ancestor
Biogeography
- Species distribution patterns are linked to evolutionary history
- Species in the same area tend to be more closely related than those in different areas
- Continental drift and plate tectonics have influenced species distribution
Fossils
- Oldest fossils are ~ 4 billion years old
- Fossils have revealed a progression of life forms over time
How is Evolution Relevant to Cell Biology?
- Explains cell evolution, diversity, and common features
- Explains cell structure, function, and adaptation to various environments
Main Events in the Evolution of Cells
- Abiogenesis
- Protocells
- RNA world
- Prokaryotes
- Endosymbiosis
- Eukaryotes
- Multicellularity
Prebiotic Synthesis
- Molecules of life can arise spontaneously in prebiotic conditions
- Lab experiments replicate early Earth conditions to study this
Protocells
- Lipids form membranes, leading to the formation of micelles and liposomes in water
- Hydrophilic heads face water and hydrophobic tails face away
RNA World
- RNA can perform both information storage and enzymatic functions
- Scientists believe that RNA preceded DNA in the evolution of life forms
- Recent experiments support this idea
Prokaryotes
- Small cells lacking internal compartments
- Evolved most biochemistry found in living things
- DNA replication, genetic code, protein synthesis (transcription/translation), photosynthesis
- Included bacteria and archaea
Endosymbiosis
- Eukaryotic organelles (like mitochondria and chloroplasts) originated from free-living prokaryotes that were engulfed by larger cells
- This eventually formed a symbiotic relationship between the host cell and the engulfed cell.
Eukaryotes
- Complex cells with membrane-bound organelles (compartmentalization)
- Endomembrane system
- Bigger than prokaryotes
- True multicellularity
- Multiple chromosomes
- Mitosis & meiosis
- Increased diversity
Multicellularity
- First multicellular organisms ~2.7 billion years ago
- Took off around 1 billion years ago
- A strong selective advantage over unicellular organisms
- Advantages include size, competition for food, protection from predators, and division of labor; increased complexity, and ability to overcome limits to cell size
Studying That Suits You
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Description
Test your understanding of key concepts in evolution and cell biology from Chapter 5. This quiz covers topics such as natural selection, the relationship between genotype and phenotype, and fundamental cellular functions. Challenge yourself with questions about microevolution, macroevolution, and the principles behind Darwinian evolution.