A108 Bio Test 1 (Semester 1)

What are the components (process) of Scientific Method?

1. Observation

2. Question

3. Hypothesis

4. Experiment

5. Analysis

6. Conclusion

Describe Inductive and Deductive Reasoning

• Inductive: Facts used to make a hypothesis

  • Students who attend classes get high grades
    
    

• Deductive: Possible relationship of different factors used to make a prediction of an existing observation/theory

  • If a student attends more classes, they will get higher grades

Describe the Independent, Dependent, Control variable

Independent: experimental variable that is being tested to observe/note a change

Dependent: responding variable that changes due to the experimental/independent variable

Control: Fixed variable that is used to ensure that the change is due to the experimental/independent variable and not another factor

What are the 7 Characteristics of life? Give a human example for each

1. Are organized (Hierarchy)

2. Acquire materials and energy (food for energy)

3. Reproduce (sexual reproduction)

4. Respond to stimuli (pupil dilation when looking at sun)

5. Are Homeostatic (body temperature: sweating/chills)

6. Grow and Develop (growing; mental development)

7. Have the capacity to adapt (more clothes in the winter)

How are living things organized?

1. Atom

2. Molecule

3. Cell

4. Tissue

5. Organ

6. Organ System

7. Organism

8. Species

9. Population

10. Community

11. Ecosystem

12. Biosphere

List the categories of classification

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Describe Lamarck's and Darwin's Theories of Evolution

• Lamarck: Inheritance of acquired characteristics

  • Environment causes change in an individual and is passed to their offspring

    • Giraffes stretched their necks to reach food in trees; passed onto offspring
      
      

• Darwin: Natural Selection

  • Individuals with traits better suited for the environment survive and produce offspring with said traits

    • Giraffes with longer necks could reach more food and survive better, producing more offspring with long necks

Describe the 5 processes of evolution

1. Gene Flow (movement of alleles between populations)
   - Individuals migrate from one population to another and produce offspring, mixing genetic diversity

2. Natural Selection (favorable traits survive in an environment)

3. Genetic Drift (change in a population's allele frequency due to random chance
   - Natural disasters/random events (ran over, stepped on, etc.)
   - Founders Effect: original population colonized a new area
   - Bottleneck Effect: natural disasters leave few survivors of the original population

4. Mutations: Changes in the DNA (random; beneficial/harmful)

5. Non-Random Mating: selective mating with an individual with a preferred trait

Describe the 4 evidences of evolution

1. Fossils:
   - Transitional Links between groups: traits shared between ancestors and descendants

2. Biogeographical: Continental Drift: position of the continents/oceans have shifted throughout Earth's history

3. Biochemical: similar DNA/genetic code between species

4. Anatomical:
   - Homologous Structures: anatomically similar structures due to a common ancestor (same structure different function; lizard (digging), bird (flying))
   - Analogous Structures: Not anatomically similar; not from a common ancestor (same function due to similar environments (whale, turtle (swimming))

Describe Microevolution and Macroevolution

• Microevolution: Species variation (different dog breeds)

• Macroevolution: evolution resulting in a new species
  - Speciation: one species gives rise to two species (new species of salamanders evolving from a single species)

What is the difference between prokaryotic and eukaryotic cells?

Prokaryote: lack membrane-bound organelles
Eukaryote: have membrane-bound organelles (nucleus/genetic material)

List the 3 types of cytoskeleton fibers/filaments and describe the function and shape/size of each

1. Actin Filaments
- Smallest of the three; long, thin
- Determines cell shape and allows movement of the cell; arranged in various forms for different functions
- Allows intestinal microvilli to expand and contract

2. Intermediate Filaments
- size is in-between the actin filaments and microtubules
- single rod-like protein polypeptide chain (monomer) with N and C-terminal domains coil together to create an intermediate filament bundle
- supports the nuclear envelope, holding cell together

3. Microtubules
- largest cytoskeletal protein
- hollow cylinder made of ⍺ tubulins and ℬ tubulins
- interacts with specific proteins to cause organelle movement
- radiate from a region (centrosome): Microtubule Organizing Centre (MTOC)

Describe the Structure and function of the Cell Membrane; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • Made of phospholipid bilayer with pores and transport proteins allowing certain molecules through

  • Structure is described as the fluid mosaic model: proteins float around the lipid layer like boats on water

• Function:

  • Acts as a protective barrier, separating the inside of the cell from the outside environment

  • Maintains cell shape

  • Helps cell communication by recognizing cell signal

• Found in:

  • Both

• Similar to:

  • Bouncer that only lets certain VIPs in/out of the club (cell)

Describe the Structure and function of the Cytoplasm; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • Gel-like substance where all organelles are suspended in; mainly composed of water, protein, salts

  • Fills the inside of both prokaryotic and eukaryotic cells
    
    

• Function:

  • Acts as a medium for all cell functions

  • Helps in the movement of cellular matter in the cell

  • Provides interior shape to the cell
    
    

• Found in:

  • Both
    
    

• Similar to:

  • Water in a swimming pool; swimmers are the organelles

Describe the Structure and function of the Nucleus; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • Membrane-bound organelle at the center of the cell

  • Inside is the genetic material (DNA and proteins) and the nucleolus: site of ribosome production

  • Fluid-filled space within is called nucleoplasm
    
    

• Function:

  • Stores DNA + DNA Replication

  • Nuclear pores control passage of certain molecules (mRNA, ribosomes) out of the nucleus
    
    

• Found in: 

  • Both
    
    

• Similar to: 

  • Large sphere with DNA and production of ribosomes
    
    
    

Describe the Structure and function of the Ribosomes; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure: 

  • Spherical

  • Made of ribosomal RNA and proteins

  • Free-floating or attached to other organelles (rough Endoplasmic Reticulum (ER))

  • Two subunits: small and large
    
    

• Function: 

  • Key role in protein synthesis (essential for cell growth/repair)

  • Coding messenger RNA (mRNA):

    • Small Subunit: reads messenger RNA (mRNA)

    • Large Subunit: binds transfer RNA (tRNA) and joins amino acids
      
      

• Found in: 

  • Both
    
    

• Similar to: 

  • Factories: read cell instructions and build proteins

  • Kitchen: Ingredients (amino acids), following recipe (mRNA), creating the dish (protein)
    
    

Describe the Structure and function of the Smooth Endoplasmic Reticulum (ER); Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • No ribosomes

  • Flat/branching sacs/tubes

  • Continuous with the nuclear membrane
    
    

• Function: 

  • Transports materials

  • Synthesizes phospholipids and detoxifies certain chemicals
    
    

• Found in: 

  • Both
    
    

• Similar to:

  • Manufacturing and detoxification factory: produces lipids and detoxifies harmful substances

Describe the Structure and function of the Rough Endoplasmic Reticulum (ER); Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure: 

  • Lined with Ribosomes

  • Flattened sacs (Cisternae)
    
    

• Function: 

  • Processes + folds and modifies proteins destined for the cell membrane or secretion from the cells

  • Protein quality control center: transports finished products to the Golgi Apparatus via vesicles
    
    

• Found in:

  • Both
    
    

• Similar to: 

  • Factory assembly line: workers (ribosomes) on the line synthesize/process/modify proteins

Describe the Structure and function of the Golgi Apparatus; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure: 

  • Stack of flattened sacs (like folded ribbons)

  • Small bubbles (vesicles) around to help transport materials to and from
    
    

• Function:

  • Stores, modifies, transports proteins and lipids into vesicles and to wherever in/out of the cell
    
    

• Found in: 

  • Both
    
    

• Similar to: 

  • Post office/shipping center: packages materials, gives them a ""zip code"" and sends them off to their destination
    
    

Describe the Structure and function of the Lysosome; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure: 

  • Dense spheres containing digestive enzymes 
    
    

• Function: 

  • Clean up any ""worn-out/impure"" (bacteria, harmful material, etc.) parts of the cell; Digestive enzymes digest molecules

  • Involved in programmed cell death (apoptosis)
    
    

• Found in: 

  • Animal Cells
    
    

• Similar to:

  • Recycling center: destroys impurities but creates new material from digested molecules that can be used for creating other cell structures

  • Janitor/Hitman: Cleans up/kills any damaged cells

Describe the Structure and function of the Peroxisome; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • Made of many transport proteins

  • Consists of a plasma membrane and a lipid layer

  • Inside: matrix and hydrolytic (breaking down) enzyme mixture
    
    

• Function:

  • Break down fatty acids and produce hydrogen peroxide, which breaks down into water and oxygen

  • Detoxify harmful substances

  • Synthesis of specific lipids
    
    

• Found in: 

  • Both
    
    

• Similar to: 

  • Hazmat crew: neutralize dangerous substances before they spread

Describe the Structure and function of the Mitochondria; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure: 

  • Rod-shaped (kidney bean)

  • Outer membrane: smooth, like a protective barrier

  • Inner membrane: folded (increases surface area) cristae: location where ATP is made 

  • Filled with fluid called the Matrix: site of Krebs cycle
    
    

• Function:

  • ATP production (cellular respiration)
    
    

• Found in: 

  • Both
    
    

• Similar to: 

  • Powerhouse of the cell: produces/provides energy

Describe the Structure and function of the Cytoskeleton (Actin Filaments); Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure: 

  • Cytoskeleton: Layer of protein fibers throughout the cell

  • Actin Filament: Very thin, flexible protein fibers composed of two intertwined strands of actin (protein)
    
    

• Function: 

  • Cytoskeleton: Structure/shape of cell

  • Actin Filament: Rigidity/shape of cell, allowing cell movement and change to shape

    • Track for motor protein myosin, allowing cell events that require motion

    • Plays a role in cell division
      
      

• Found in:

  • Both
    
    

• Similar to:

  • Skeleton of the cell: allows movement

Describe the Structure and function of the Cytoskeleton (Intermediate Filaments); Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure: 

  • Rope-like structures that are medium in size between actin filaments and microtubules

  • Flexible to maintain shape
    
    

• Function: 

  • Provide structural support: maintain cell shape and anchor organelles in place

  • Create cell-to-cell junctions (skin cells held tight together)
    
    

• Found in:

  • Both
    
    

• Similar to:

  • Skeleton of the cell: allows movement

Describe the Structure and function of the Cytoskeleton (Microtubules); Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • Long hollow tubes made of repeating protein units called tubulin

  • Largest of the three cytoskeleton fibers

  • Found in centrosomes which are involved in cell division
    
    

• Function:

  • Cell movement: provide structure to cilia and flagella, allowing movement of bacteria/prokaryotes

  • Form mitotic spindle during mitosis, which separate chromosomes

  • Transport organelles/vesicles: tracks for motor proteins (carts on rails)

  • Maintain cell shape
    
    

• Found in:

  • Both

    • Animal cells have two centrioles inside centrosomes; plant cells do not have centrioles
      
      

• Similar to:

  • Spiderweb: hollow tubes creating a framework

  • Microscopic train tracks: move materials where needed and keep it organized

Describe the Structure and function of the Flagella and Cilia; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • Flagella: has a ""tail"" on the end; common in prokaryotes and some eukaryotes

  • Cilia: hair-like organelle; common in eukaryotes
    
    

• Function: 

  • Both: Movement (locomotion)

    • Cilia: cell signaling, fluid transportation
      
      

• Found in:

  • Animals
    
    

• Similar to: 

  • Flagella: tail (sperm)

  • Cilia: brush

Describe the Structure and function of the Small Vacuoles; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • Tiny round/oval bubble-like sac filled with fluid 

  • Found all around the cytoplasm
    
    

• Function: 

  • Temporary storage, storage, and disposal

  • Helps maintain homeostasis
    
    

• Found in:

  • Animal Cells
    
    

• Similar to:

  • Water balloons

  • Storage unit/bag check

Describe the Structure and function of the Central (Large) Vacuole; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • Large clear bubble in the center of the cell

  • Surrounded by a thin membrane called the tonoplast 

  • Pushes the nucleus and other organelles to the sides
    
    

• Function:

  • Regulates internal cell environment, storing water, nutrients and waste products

  • Maintains turgor pressure, keeping the plant firm and upright, holding water and pressing against the cell wall

  • Supports cell growth by expanding as it fills with water
    
    

• Found in:

  • Plants
    
    

• Similar to:

  • Large water balloon in a box
    
    
    

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Describe the Structure and function of the Cell Wall; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • Built of cellulose and protein

  • Thick layer around the plant cell
    
    

• Function:

  • Maintains cell shape

  • Keeps inside safe, creating a barrier from the outside
    
    

• Found in:

  • Plant
    
    

• Similar to: 

  • Gated community/fence: surrounds/protects the inside and gives it shape/structure
    
    
    

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Describe the Structure and function of the Chloroplast; Is it found in a plant or animal cell (both?) What is similar to? (Analogy)

• Structure:

  • Bright green disk-shaped: green due to chlorophyll 

  • Contains structures: 

    • Thylakoids: flat green sacs

    • Grana: stacks of Thykaloids

    • Stroma: fluid surrounding the thylakoids
      
      

• Function:

  • Photosynthesis: absorbing sunlight to produce energy

    • Turns carbon dioxide into Glucose
      
      

• Found in:

  • Plant
    
    

• Similar to: 

  • Solar Panel: absorb sunlight to generate energy (glucose) to power a home (plant)

Label the following diagram (Animal or Plant cell?): 

Animal Cell

Label the following diagram (Animal or Plant Cell?):

Plant Cell

Why are our cells the size they are? 

"Small cell size means more cells = more surface area
As cells increase in volume, surface area decreases

The amount of surface area affects the ability to get materials in/out of the cell

What is the Cell Theory? (3)

1. Cells are the basic unit of life

2. All living organisms are composed of one or more cells

3. All cells come only from previously existing cells

Define the Endosymbiotic Theory

Mitochondria and Chloroplasts are derived from prokaryotes; evolution of complex eukaryotic cells from simple prokaryotic cells

1. Mitochondria + Chloroplasts are similar to bacteria in size and structure

2. Both are bound by a double membrane:
   - Outer: may be from engulfing vesicle
   - Inner: may be from plasma membrane of original prokaryote

3. Mitochondria + Chloroplast contain limited genetic material and divide by splitting

4. Most proteins within both are produced by the eukaryotic host, but they also produce some proteins and have their own ribosomes which resemble those of prokaryotes

5. RNA (ribonucleic acid) base sequence of the ribosomes in them suggests a prokaryotic origin
   
   
   

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