Home » Biology » Laboratory Investigation V: Onion Root Tip Mitosis Lab

Bryan Cardella

Bryan Cardella

Laboratory Investigation V: Onion Root Tip Mitosis Lab

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Table of Contents

Section 1: Introduction to Biology
Scientific Method

26m 23s

Intro
0:00
Origins of the Scientific Method
0:04
Steps of the Scientific Method
3:08
Observe
3:21
Ask a Question
4:00
State a Hypothesis
4:08
Obtain Data (Experiment)
4:25
Interpret Data (Result)
5:01
Analysis (Form Conclusions)
5:38
Scientific Method in Action
6:16
Control vs. Experimental Groups
7:24
Independent vs. Dependent Variables
9:51
Other Factors Remain Constant
11:03
Scientific Method Example
13:58
Scientific Method Illustration
17:35
More on the Scientific Method
22:16
Experiments Need to Duplicate
24:07
Peer Review
24:46
New Discoveries
25:23
Molecular Basis of Biology

46m 22s

Intro
0:00
Building Blocks of Matter
0:06
Matter
0:32
Mass
1:10
Atom
1:48
Ions
5:50
Bonds
8:29
Molecules
9:55
Ionic Bonds
9:57
Covalent Bonds
11:10
Water
12:30
Organic Compounds
17:48
Carbohydrates
18:04
Lipids
19:43
Proteins
20:42
Nucleic Acids
22:21
Carbohydrates
22:54
Sugars
22:56
Functions
23:42
Molecular Representation Formula
26:34
Examples
27:15
Lipids
28:44
Fats
28:46
Triglycerides
29:04
Functions
32:10
Steroids
33:43
Saturated Fats
34:18
Unsaturated Fats
36:08
Proteins
37:26
Amino Acids
37:58
3D Structure Relates to Their Function
38:54
Structural Proteins vs Globular Proteins
39:41
Functions
40:41
Nucleic Acids
42:53
Nucleotides
43:04
DNA and RNA
44:34
Functions
45:07
Section 2: Cells: Structure & Function
Cells: Parts & Characteristics

1h 12m 12s

Intro
0:00
Microscopes
0:06
Anton Van Leeuwenhoek
0:58
Robert Hooke
1:36
Matthias Schleiden
2:52
Theodor Schwann
3:19
Electron Microscopes
4:16
SEM and TEM
4:54
The Cell Theory
5:21
3 Tenets
5:24
All Organisms Are Composed of One Or More Cells
5:46
The Cell is the Basic Unit of Structure and Function for Organisms
6:01
All Cells Comes from Preexisting Cells
6:34
The Characteristics of Life
8:09
Display Organization
8:18
Grow and Develop
9:12
Reproduce
9:33
Respond to Stimuli
9:55
Maintain Homeostasis
10:23
Can Evolve
11:37
Prokaryote vs. Eukaryote
11:53
Prokaryote
12:13
Eukaryote
14:00
Cell Parts
16:53
Plasma Membrane
18:27
Cell Membrane
18:29
Protective and Regulatory
18:52
Semi-Permeable
19:18
Polar Heads with Non-Polar Tails
20:52
Proteins are Imbedded in the Layer
22:46
Nucleus
25:53
Contains the DNA in Nuclear Envelope
26:31
Brain on the Cell
28:12
Nucleolus
28:26
Ribosome
29:02
Protein Synthesis Sites
29:25
Made of RNA and Protein
29:29
Found in Cytoplasm
30:24
Endoplasmic Reticulum
31:49
Adjacent to Nucleus
32:07
Site of Numerous Chemical Reactions
32:37
Rough
32:56
Smooth
33:48
Golgi Apparatus
34:54
Flattened Membranous Sacs
35:10
Function
35:45
Cell Parts Review
37:06
Mitochondrion
39:45
Mitochondria
39:50
Membrane-Bound Organelles
40:07
Outer Double Membrane
40:57
Produces Energy-Storing Molecules
41:46
Chloroplast
43:45
In Plant Cells
43:47
Membrane-Bound Organelles with Their Own DNA and Ribosomes
44:20
Thylakoids
44:59
Produces Sugars Through Photosynthesis
45:46
Vacuoles/ Vesicles
46:44
Vacuoles
47:03
Vesicles
47:59
Lysosome
50:21
Membranous Sac for Breakdown of Molecules
50:34
Contains Digestive Enzymes
51:55
Centrioles
53:15
Found in Pairs
53:18
Made of Cylindrical Ring of Microtubules
53:22
Contained Within Centrosomes
53:51
Functions as Anchors for Spindle Apparatus in Cell Division
54:06
Spindle Apparatus
55:27
Cytoskeleton
55:55
Forms Framework or Scaffolding for Cell
56:05
Provides Network of Protein Fibers for Travel
56:24
Made of Microtubules, Microfilaments, and Intermediate Filaments
57:18
Cilia
59:21
Cilium
59:27
Made of Ring of Microtubules
1:00:00
How They Move
1:00:35
Flagellum
1:02:42
Flagella
1:02:51
Long, Tail-Like Projection from a Cell
1:02:59
How They Move
1:03:27
Cell Wall
1:05:21
Outside of Plasma Membrane
1:05:25
Extra Protection and Rigidity for a Cell
1:05:52
In Plants
1:07:19
In Bacteria
1:07:25
In Fungi
1:07:41
Cytoplasm
1:08:07
Fluid-Filled Region of a Cell
1:08:24
Sight for Majority of the Cellular Reactions
1:08:47
Cytosol
1:09:29
Animal Cell vs. Plant Cell
1:09:10
Cellular Transport

32m 1s

Intro
0:00
Passive Transport
0:05
Movement of Substances in Nature Without the Input of Energy
0:14
High Concentration to Low Concentration
0:36
Opposite of Active Transport
1:41
No Net Movement
3:20
Diffusion
3:55
Definition of Diffusion
3:58
Examples
4:07
Facilitated Diffusion
7:32
Definition of Facilitated Diffusion
7:49
Osmosis
9:34
Definition of Osmosis
9:42
Examples
10:50
Concentration Gradient
15:55
Definition of Concentration Gradient
16:01
Relative Concentrations
17:32
Hypertonic Solution
17:48
Hypotonic Solution
20:07
Isotonic Solution
21:27
Active Transport
22:49
Movement of Molecules Across a Membrane with the Use Energy
22:51
Example
23:30
Endocytosis
25:53
Wrapping Around of Part of the Plasma
26:13
Examples
26:26
Phagocytosis
28:54
Pinocytosis
29:02
Exocytosis
29:40
Releasing Material From Inside of a Cell
29:43
Opposite of Endocytosis
29:50
Cellular Energy, Part I

52m 11s

Intro
0:00
Energy Facts
0:05
Law of Thermodynamics
0:16
Potential Energy
2:27
Kinetic Energy
2:50
Chemical Energy
3:01
Mechanical Energy
3:20
Solar Energy
3:41
ATP Structure
4:07
Adenosine Triphosphate
4:12
Common Energy Source
4:25
ATP Function
6:13
How It Works
7:18
What It Is Used For
7:43
GTP
9:36
ATP Cycle
10:35
ATP Formation
10:49
ATP Use
12:12
Enzyme Basics
13:51
Catalysts
13:59
Protein-Based
14:39
Reaction Occurs
14:51
Enzyme Structure
19:14
Active Site
19:23
Induced Fit
20:15
Enzyme Function
21:22
What Enzymes Help With
21:31
Inhibition
21:57
Ideal Environment to Function Properly
22:57
Enzyme Examples
25:26
Amylase
25:34
Catalase
26:03
DNA Polymerase
26:21
Rubisco
27:06
Photosynthesis
28:19
Process To Make Glucose
28:27
Photoauthotrophs
28:34
Endergonic
30:08
Reaction
30:22
Chloroplast Structure
31:55
Photosynthesis Factories Found in Plant Cells
32:26
Thylakoids
32:29
Stroma
33:18
Chloroplast Micrograph
34:14
Photosystems
34:46
Thylakoid Membranes Are Filled with These Reaction Centers
34:58
Photosystem II and Photosystem I
35:47
Light Reactions
37:09
Light-Dependent Reactions
37:24
Step 1
37:35
Step 2
38:31
Step 3
39:33
Step 4
40:33
Step 5
40:51
Step 6
41:30
Dark Reactions
43:15
Light-Independent Reactions or Calvin Cycle
43:19
Calvin Cycle
44:54
Cellular Energy, Part II

40m 50s

Intro
0:00
Aerobic Respiration
0:05
Process of Breaking Down Carbohydrates to Make ATP
0:45
Glycolysis
1:44
Krebs Cycle
1:48
Oxidative Phosphorylation
2:06
Produces About 36 ATP
2:24
Glycolysis
3:35
Breakdown of Sugar Into Pyruvates
4:16
Occurs in the Cytoplasm
4:30
Krebs Cycle
11:40
Citric Acid Cycle
11:42
Acetyl-CoA
12:04
How Pyruvate Gets Modified into acetyl-CoA
12:35
Oxidative Phosphorylation
22:45
Anaerobic Respiration
29:44
Lactic Acid Fermentation
31:06
Alcohol Fermentation
31:51
Produces Only the ATP From Glycolysis
32:09
Aerobic Respiration vs. Photosynthesis
36:43
Cell Division

1h 9m 12s

Intro
0:00
Purposes of Cell Division
0:05
Growth and Development
0:17
Tissue Regeneration
0:51
Reproduction
1:51
Cell Size Limitations
4:01
Surface-to-Volume Ratio
5:33
Genome-to-Volume Ratio
10:29
The Cell Cycle
12:20
Interphase
13:23
Mitosis
14:08
Cytokinesis
14:21
Chromosome Structure
16:08
Sister Chromatids
19:00
Centromere
19:22
Chromatin
19:48
Interphase
21:38
Growth Phase #1
22:25
Synthesis of DNA
23:09
Growth Phase #2
23:52
Mitosis
25:13
4 Main Phases
25:21
Purpose of Mitosis
26:40
Prophase
28:46
Condense DNA
28:56
Nuclear Envelope Breaks Down
29:44
Nucleolus Disappears
30:04
Centriole Pairs Move to Poles
30:31
Spindle Apparatus Forms
31:22
Metaphase
32:36
Chromosomes Line Up Along Equator
32:43
Metaphase Plate
33:29
Anaphase
34:21
Sister Chromatids are Separated
34:26
Sister Chromatids Migrate Towards Poles
36:59
Telophase
37:17
Chromatids Become De-Condensed
37:31
Nuclear Envelope Reforms
37:59
Nucleoli Reappears
38:22
Spindle Apparatus Breaks Down
38:32
Cytokinesis
39:01
In Animal Cells
39:31
In Plant Cells
40:38
Cancer in Relation to Mitosis
41:59
Cancer Can Occur in Multicellular Organism
42:31
Particular Genes Control the Pace
43:11
Benign vs. Malignant
45:13
Metastasis
46:45
Natural Killer Cells
47:33
Meiosis
48:17
Produces 4 Cells with Half the Number of Chromosomes
49:02
Produces Genetically Unique Daughter Cells
51:56
Meiosis I
52:39
Prophase I
53:14
Metaphase I
57:44
Anaphase I
59:10
Telophase I
1:00:00
Meiosis II
1:01:04
Prophase II
1:01:08
Metaphase II
1:01:32
Anaphase II
1:02:08
Telophase II
1:02:43
Meiosis Overview
1:03:39
Products of Meiosis
1:06:00
Gametes
1:06:10
Sperm and Egg
1:06:17
Different Process for Spermatogenesis vs. Oogenesis
1:06:27
Section 3: From DNA to Protein
DNA

51m 42s

Intro
0:00
DNA: Its Role and Characteristics
0:05
Deoxyribonucleic Acid
0:17
Double Helix
1:28
Nucleotides
2:31
Anti-parallel
2:46
Self-Replicating
3:36
Codons, Genes, Chromosomes
3:56
DNA: The Discovery
5:13
DNA First Mentioned
5:50
Bacterial Transformation with DNA
6:32
Base Pairing Rule
8:06
DNA is Hereditary Material
9:44
X-Ray Crystallography Images
10:46
DNA Structure
11:49
Nucleotides
12:54
The Double Helix
16:34
Hydrogen Bonding
16:40
Backbone of Phosphates and Sugars
19:25
Strands are Anti-Parallel
19:37
Nitrogenous Bases
20:52
Purines
21:38
Pyrimidines
22:46
DNA Replication Overview
24:33
DNA Must Duplicate Every Time a Cell is Going to Divide
24:34
Semiconservative Replication
24:49
How Does it Occur?
27:34
DNA Replication Steps
28:39
DNA Helicase Unzips Double Stranded DNA
28:49
RNA Primer is Laid Down
29:10
DNA Polymerase Attaches Complementary Bases in Continuous Manner
30:07
DNA Polymerase Attaches Complementary Bases in Fragments
31:06
DNA Polymerase Replaces RNA Primers
31:22
DNA Ligase Connects Fragments Together
31:44
DNA Replication Illustration
32:25
'Junk' DNA
45:02
Only 2% of the Human Genome Codes for Protein
45:11
What Does Junk DNA Mean to Us?
46:52
DNA Technology Uses These Sequences
49:20
RNA

51m 59s

Intro
0:00
The Central Dogma
0:04
Transcription
0:57
Translation
1:11
RNA: Its Role and Characteristics
2:02
Ribonucleic Acid
2:06
How It Is Different From DNA
2:59
DNA and RNA Differences
5:00
Types of RNA
6:01
Messenger RNA
6:15
Ribosomal RNA
6:49
Transfer RNA
7:52
Others
8:54
Transcription
9:26
Process in Which RNA is Made From a Gene in DNA
9:30
How It's Done
9:55
Summary of Steps
10:35
Transcription Steps
11:54
Initiation
11:57
Elongation
15:57
Termination
18:10
RNA Processing
21:35
Pre-mRNA
21:37
Modifications
21:53
Translation
27:01
Process in Which mRNA Binds with a Ribosome and tRNA and rRNA Assist
27:03
Summary of Steps
28:39
Translation the mRNA Code
28:59
Every Codon in mRNA Gets Translated to an Amino Acid
29:14
Chart Providing the Resulting Translation
29:19
Translation Steps
32:20
Initiation
32:23
Elongation
35:31
Termination
38:43
Mutations
40:22
Code in DNA is Subject to Change
41:00
Why Mutations Happen
41:23
Point Mutation
43:16
Insertion / Deletion
47:58
Duplications
50:03
Genetics, Part I

1h 15m 17s

Intro
0:00
Gregor Mendel
0:05
Father of Genetics
0:39
Experimented with Crossing Peas
1:02
Discovered Consistent Patterns
2:37
Mendel's Laws of Genetics
3:10
Law of Segregation
3:20
Law of Independent Assortment
5:07
Genetics Vocabulary #1
6:28
Gene
6:42
Allele
7:18
Homozygous
8:25
Heterozygous
9:39
Genotype
10:15
Phenotype
11:01
Hybrid
11:53
Pure Breeding
12:28
Generation Vocabulary
13:03
Parental Generation
13:25
1st Filial
13:58
2nd Filial
14:06
Punnett Squares
15:07
Monohybrid Cross
18:52
Mating Pure-Breeding Peas in the P Generation
19:09
F1 Cross
21:31
Dihybrid Cross Introduction
23:42
Traced Inheritance of 2 Genes in Pea Plants
23:50
Dihybrid Cross Example
26:07
Phenotypic Ratio
31:34
Incomplete Dominance
32:02
Blended Inheritance
32:27
Example
32:35
Epistasis
35:05
Occurs When a Gene Has the Ability to Completely Cancel Out the Expression of Another Gene
35:10
Example
35:30
Multiple Alleles
40:12
More Than Two Forms of Alleles
40:23
Example
41:06
Polygenic Inheritance
46:50
Many Traits Get Phenotype From the Inheritance of Numerous Genes
46:58
Example
47:26
Test Cross
51:53
In Cases of Complete Dominance
52:03
Test Cross Demonstrates Which Genotype They Have
52:52
Sex-Linked Traits
53:56
Autosomes
54:21
Sex Chromosomes
54:57
Genetic Disorders
59:31
Autosomal Recessive
1:00:00
Autosomal Dominant
1:06:17
Sex-Linked Recessive
1:09:19
Sex-Linked Dominant
1:13:41
Genetics, Part II

49m 57s

Intro
0:00
Karotyping
0:04
Process to Check Chromosomes for Abnormal Characteristics
0:08
Done with Cells From a Fetus
0:58
Amniocentesis
1:02
Normal Karotype
2:43
Abnormal Karotype
4:20
Nondisjunction
5:14
Failure of Chromosomes to Properly Separate During Meiosis
5:16
Nondisjunction
5:45
Typically Causes Chromosomal Disorders Upon Fertilization
6:33
Chromosomal Disorders
10:52
Autosome Disorders
11:01
Sex Chromosome Disorders
14:06
Pedigrees
20:29
Visual Depiction of an Inheritance Pattern for One Gene in a Family's History
20:30
Symbols
20:46
Trait Being Traced is Depicted by Coloring in the Individual
21:58
Pedigree Example #1
22:26
Pedigree Example #2
25:02
Pedigree Example #3
27:23
Environmental Impact
30:24
Gene Expression Is Often Influenced by Environment
30:25
Twin Studies
30:35
Examples
31:45
Genetic Engineering
36:03
Genetic Transformation
36:17
Restriction Enzymes
39:09
Recombinant DNA
40:37
Gene Cloning
41:58
Polymerase Chain Reaction
43:13
Gel Electrophoresis
44:37
Transgenic Organisms
48:03
Section 4: History of Life
Evolution

1h 47m 19s

Intro
0:00
The Scientists Behind the Theory
0:04
Fossil Study and Catastrophism
0:18
Gradualism
1:13
Population Growth
2:00
Early Evolution Thought
2:37
Natural Selection As a Sound Theory
8:05
Darwin's Voyage
8:59
Galapagos Islands Stop
9:15
Theory of Natural Selection
11:24
Natural Selection Summary
12:37
Populations have Enormous Reproductive Potential
13:45
Population Sizes Tend to Remain Relatively Stable
14:55
Resources Are Limited
16:51
Individuals Compete for Survival
17:16
There is Much Variation Among Individuals in a Population
17:36
Much Variation is Heritable
18:06
Only the Most Fit Individuals Survive
18:27
Evolution Occurs As Advantageous Traits Accumulate
19:23
Evidence for Evolution
19:47
Molecular Biology
19:53
Homologous Structures
22:55
Analogous Structures
26:20
Embryology
29:36
Paleontology
34:54
Patterns of Evolution
40:14
Divergent Evolution
40:37
Convergent Evolution
43:15
Co-Evolution
46:07
Gradualism vs. Punctuated Equilibrium
49:56
Modes of Selection
52:25
Directional Selection
54:40
Disruptive Selection
56:38
Stabilizing Selection
58:07
Artificial Selection
59:56
Sexual Selection
1:02:13
More on Sexual Selection
1:03:00
Sexual Dimorphism
1:03:26
Examples
1:04:50
Notes on Natural Selection
1:09:41
Phenotype
1:10:01
Only Heritable Traits
1:11:00
Mutations Fuel Natural Selection
11:39
Reproductive Isolation
1:12:00
Temporal Isolation
1:12:59
Behavioral Isolation
1:14:17
Mechanical Isolation
1:15:13
Gametic Isolation
1:16:21
Geographic Isolation
1:16:51
Reproductive Isolation (Post-Zygotic)
1:18:37
Hybrid Sterility
1:18:57
Hybrid Inviability
1:20:08
Hybrid Breakdown
1:20:31
Speciation
1:21:02
Process in Which New Species Forms From an Ancestral Form
1:21:13
Factors That Can Lead to Development of a New Species
1:21:19
Adaptive Radiation
1:24:26
Radiating of Various New Species
1:24:28
Changes in Appearance
1:24:56
Examples
1:24:14
Hardy-Weinberg Theorem
1:27:35
Five Conditions
1:28:15
Equations
1:33:55
Microevolution
1:36:59
Natural Selection
1:37:11
Genetic Drift
1:37:34
Gene Flow
1:40:54
Nonrandom Mating
1:41:06
Clarifications About Evolution
1:41:24
A Single Organism Cannot Evolve
1:41:34
No Single Missing Link with Human Evolution
1:43:01
Humans Did Not Evolve from Chimpanzees
1:46:13
Human Evolution

47m 31s

Intro
0:00
Primates
0:04
Typical Primate Characteristics
1:12
Strepsirrhines
3:26
Haplorhines
4:08
Anthropoids
5:03
New World Monkeys
5:15
Old World Moneys
6:20
Hominoids
6:51
Hominins
7:51
Hominins
8:46
Larger Brains
8:53
Thinner, Flatter Face
9:02
High Manual Dexterity
9:30
Bipedal
9:41
Australopithecines
12:11
Earliest Fossil Evidence for Bipedalism
12:24
Earliest Australopithecines
13:06
Lucy
13:35
The Genus 'Homo'
15:20
Living and Extinct Humans
16:46
Features
16:52
Tool Use
17:09
Homo Habilis
17:38
2.4 - 1.4 mya
18:38
Handy Human
19:19
Found In Africa
19:33
Homo Ergaster
20:11
1.8 - 1.2 mya
20:14
Features
20:25
Found In and Outside of Africa
20:41
Most Likely Hunted
21:03
Homo Erectus
21:32
1.8 - 0.4 mya
22:04
Upright Human
22:49
Found in Africa, Asia, and Europe
22:52
Features
22:57
Used Fire
23:07
Homo Heidelbergensis
23:45
1.3 - 0.2 mya
23:50
Transitional Form
24:22
Features
24:36
Homo Sapiens Neanderthalensis
24:56
0.3 - 0.2 mya
25:23
Neander Valley
25:31
Found in Europe and Asia
21:53
Constructed Complex Structures
27:50
Modern Human and Neanderthal
28:50
Homo Sapiens Sapiens
29:34
195,000 Years Ago - Present
29:37
Humans Most Likely Evolved Once
29:50
Features
30:26
Creative and More Control Over the Environment
30:37
Homo Floresiensis
31:36
18,000 Years Old
31:40
The Hobbit
32:09
Brain and Body Proportions are Similar to Australopithecines
32:16
Human Migration Summary
32:49
Origins of Life

40m 58s

Intro
0:00
Brief History of Earth
0:05
About 4.5 Billion Years Old
0:13
Started Off as a Fiery Ball of Hot Volcanic Activity
1:12
Atmospheric Gas of Early Earth
2:20
Gases Expelled Out of Volcanic Vents
3:10
Building Blocks to Organic Compounds
4:47
Miller-Urey Experiment (1953)
5:41
Stanley Miller and Harold Urey
5:48
Amino Acids Were Found in the Sterile Water Beneath
7:27
Protobionts
8:07
Ancestors of Cells as We Know Them
8:19
Lipid Bubbles with Organic Compounds Inside
8:32
Origin of DNA
12:07
First Cells
12:12
RNA Originally Coded for Protein
12:44
DNA Allows for Retention and a Checking for Errors
12:55
Oxygen Surge
14:57
Photosynthesis Changes Oxygen Gas in Atmosphere
16:36
Cells Absorb Solar Energy with Pigment and Could Make Sugars and Release Oxygen
17:05
Endosymbiotic Theory
18:22
First Eukaryote was Born
19:54
First Proposed by Lynn Margulis
22:43
Multicellular Origins
23:08
Cells That Kept Close Quarters and Stayed Attached Had Safety in Numbers
23:28
Hypothesis
23:45
Cambrian Explosion
26:22
Explosion of Species
27:10
Theory and Snowball Earth
28:24
Timeline of Major Events
32:00
Biogenesis

27m 25s

Intro
0:00
Spontaneous Generation
0:04
Spontaneous Generation
0:14
Pseudoscience
1:45
Individuals Who Sought to Disprove This Theory
2:49
Francesco Redi's Experiment
3:33
17th Century Italian Scientist
3:36
Wanted to Debunk the Theory That Maggots Emerge From Rotting Raw Meat
3:48
Lazzaro Spallanzani's Experiment
6:33
18th Century Italian Scientist
6:36
Wanted to Demonstrate That Microbes Could Be Airborne
6:58
Louis Pasteur's Experiment
9:47
19th Century French Scientist
9:51
Disprove Spontaneous Generation
11:17
Pasteur's Vaccine Discovery
13:47
Motivation to Discover a Way to Immunize People Against Disease
14:00
Cholera Bacteria
14:42
Vaccine Explanation
16:42
Inactive Versions of the Virus are Generated in a Culture
16:47
Antigens Injected Into the Person
17:45
Common Immunizations
22:00
Effectiveness
22:03
No Proof That Vaccines Cause Autism
26:33
Section 5: Diversity of Life
Taxonomy

35m 21s

Intro
0:00
Ancient Classification
0:04
Start of Classification Systems
0:56
How Plants and Animals Were Split Up
2:46
Used in Europe Until 1700s
3:27
Modern Classification
3:52
Carolus Linnaeus
3:58
Taxonomy
5:15
Taxonomic Groups
6:57
Domain
7:14
Kingdom
7:29
Phylum
7:39
Class
7:49
Order
8:02
Family
8:09
Genus
8:25
Species
8:45
Binomial Nomenclature
12:10
Genus Species
12:22
Naming System Rules
12:49
Advantages and Disadvantages to Taxonomy
14:56
Advantages
15:00
Disadvantages
17:53
Domains
20:31
Domain Archaea
21:10
Domain Bacteria
21:19
Domain Eukarya
21:43
Extremophiles
22:48
Kingdoms
25:09
Kingdom Archaebacteria
25:17
Kingdom Eubacteria
25:25
Kingdom Protista
25:52
Kingdom Plantae, Fungi, Animalia
27:18
Cladograms
28:07
Relates Evolution to Phylogeny
28:12
Characteristics Lead to Splitting Off Groups of Organisms
28:20
Viruses

44m 25s

Intro
0:00
Virus Basics
0:04
Non-Living Structures have the Potential to Harm Life on Earth
0:14
Made of Nucleic Acids Wrapped in a Protein Coat
2:15
5 to 300 nm Wide
3:12
Virus Structure
4:29
Icosahedral
4:41
Spherical
5:33
Bacteriophage
6:20
Helical
8:56
How Do They Invade Cells?
11:24
Viruses Can Fool Cells to Let Them In
11:27
Viruses Use the Organelles of the Host
12:29
Viruses are Host Specific
12:57
Viral Cycle
16:18
Lytic Cycle
16:34
Lysogenic Cycle
18:53
Connection Between Lytic/ Lysogenic
23:01
Retroviruses
30:04
Process is Backwards
30:52
Reverse Transcriptase
31:08
Example
31:47
HIV/ AIDS
32:38
Human Immunodeficiency Virus
32:42
Acquired Immunodeficiency Syndrome
36:27
Smallpox: A Brief History
37:06
One of the Most Harmful Viral Diseases in Human History
37:09
History
37:53
Prions
41:32
Infectious Proteins That Damage the Nervous System
41:33
Cause Transmittable Spongiform Encephalopathies
41:51
No Known Cure
43:42
Bacteria

46m 1s

Intro
0:00
Archaebacteria
0:04
Thermophiles
1:10
Halophiles
2:06
Acidophiles
2:29
Methanogens
2:59
Archaea and Bacteria Compared to Eukarya
4:25
Archaea and Eukarya
4:36
Bacteria and Eukarya
5:37
Eubacteria
6:35
Nucleoid Region
7:02
Peptidoglycan
7:21
Binary Fission
8:08
No Membrane-Bound Organelles
8:59
Bacterial Shapes
10:19
Coccus
10:26
Bacillus
12:07
Spirillum
12:44
Bacterial Cell Walls
13:17
Gram Positive
13:47
Gram Negative
15:09
Bacterial Adaptations
16:13
Capsule
16:18
Fimbriae
17:51
Conjugation
18:30
Endospore
21:30
Flagella
23:49
Metabolism
24:36
Benefits of Bacteria
27:28
Mutualism
27:32
Connections to Human Life
30:56
Diseases Caused by Bacteria
35:05
STDs
35:15
Respiratory
36:04
Skin
37:15
Digestive Tract
38:00
Nervous System
38:27
Systemic Diseases
39:09
Antibiotics
40:26
Drugs That Block Protein Synthesis
40:40
Drugs That Block Cell Wall Production
41:07
Increased Bacterial Resistance
41:36
Protists

32m 46s

Intro
0:00
Kingdom Protista Basics
0:04
Unicellular and Multicellular
0:28
Asexual and Sexual
0:48
Water and Land
1:06
Resemble Other Life Forms
1:32
Protist Origin
2:04
Evolutionary Bridge Between Bacteria and Multicellular Eukaryotes
2:06
Protist Ancestors
2:27
Protist Debate
4:18
One Kingdom
4:30
Some Scientists Group Into Separate Kingdoms Based on Genetic Links
4:37
Plant-like Protists
6:03
Photoautotrophs
6:12
Green Algae
6:44
Red Algae
7:12
Brown Algae
7:57
Golden Algae
9:10
Dinoflagellates
9:20
Diatoms
9:41
Euglena
10:17
Euglena Structure
10:39
Ulva Life Cycle
12:08
Fungi-Like Protists
15:39
Heterotrophs That Feed on Decaying Organic Matter
15:41
Found Anywhere with Moisture and Warmth
16:04
Cellular Slime Mold Life Cycle
17:34
Animal-like Protists
21:45
Heterotrophs That Eat Live Cells
21:50
Motile
22:03
Amoeba Life Cycle
25:24
How Protists Impact Humans
29:09
Good
29:16
Bad
32:18
Plants, Part I

54m 22s

Intro
0:00
Kingdom Plantae Characteristics
0:05
Cuticle
0:38
Vascular Bundles
1:18
Stomata
2:51
Alternation of Generations
4:16
Plant Origins
5:58
Common Ancestor with Green Algae
6:03
Appeared on Earth 400 Million Years Ago
7:28
Non-Vascular Plants
8:17
Bryophytes
8:45
Anthoworts
9:12
Hepaticophytes
9:19
Bryophyte (Moss) Life Cycle
9:30
Dominant Gametophyte
9:38
Illustration Explanation
9:58
Seedless Vascular Plants
15:26
Do Not Reproduce With Seeds
15:33
Sori
15:42
Lycophytes
15:54
Pterophytes
16:30
Pterophyte (Fern) Life Cycle
17:05
Dominant Generation
17:08
Produce Motile Sperm
17:17
Seed Plants
23:17
Most Vascular Plants Have Seeds
23:25
Cotyledons
23:43
Gymnosperm vs. Angiosperm
24:50
Divisions
25:48
Coniferophytes (Cone-Bearing Plants)
27:05
Examples
27:07
Evergreen or Deciduous
27:44
Gymnosperms
28:26
Economic Importance
29:28
Conifer Life Cycle
30:10
Dominant Generation
30:13
Cones Contain the Gametophyte
30:25
Illustration Explanation
30:31
Anthophytes (Flowering Plants)
38:01
Every Plant That Has Flowers
38:03
Angiosperms
38:28
Various Life Spans
38:03
Flower Anatomy
40:25
Female Parts
40:54
Male Parts
42:49
Flowering Plant Life Cycle
44:48
Dominant Generation
44:56
Flowers Contain the Gametophyte
45:05
Plants, Part II

44m 40s

Intro
0:00
Plant Cell Varieties
0:05
Parenchyma
0:11
Collenchyma
1:37
Sclerenchyma
2:03
Specialized Tissues
2:56
Plant Tissues
3:17
Meristematic Tissue
3:21
Dermal Tissue
6:46
Vascular Tissues
8:45
Ground Tissue
13:56
Roots
14:24
Root Cap
15:59
Cortex
16:17
Endodermis
17:02
Pericycle
17:42
Taproot
18:11
Fibrous
18:20
Modified
18:49
Stems
19:49
Tuber
21:43
Rhizome
21:58
Runner
22:12
Bulb and Corm
22:49
Leaves
23:06
Photosynthesis
23:09
Leaf Parts
23:32
Gas Exchange
25:55
Transpiration
26:25
Seeds
27:41
Cotyledons
28:42
Seed Coat
29:29
Endosperm
29:37
Embryo
30:10
Radicle
30:27
Epicotyl
31:57
Fruit
33:49
Fleshy Fruits
34:46
Aggregate Fruits
35:17
Multiple Fruits
35:50
Dry Fruits
36:27
Plant Hormones
37:44
Definition or Hormones
37:48
Examples
38:12
Plant Responses
40:42
Tropisms
41:00
Nastic Responses
43:04
Fungi

26m 20s

Intro
0:00
Fungi Basics
0:03
Characteristics
0:09
Closely Related to Kingdom Animalia
2:33
Fungal Structure
2:58
Hypae
3:03
Mycelium
5:00
Spore
5:24
Reproductive Strategies
6:15
Fragmentation
6:23
Budding
6:35
Spore Production
7:03
Zygomycota (Molds)
7:50
Sexual Reproduction
8:04
Dikaryotic
9:47
Stolons
10:32
Rhizoids
10:53
Ascomycota (Sac Fungi)
11:43
Largest Phylum of Fungi on Earth
11:47
Ascus
12:20
Conidia
12:30
Example
12:46
Basidiomycota (Club Fungi)
14:51
Basidium
15:14
Common Structures In These Fungi
15:37
Examples
16:17
Deuteromycota (Imperfect Fungi)
17:25
No Known Sexual Life Cycle
17:31
Penicillin
18:00
Benefits of Fungi
18:51
Mutualism
18:56
Food
21:41
Medicines
22:30
Decomposition
23:08
Fungal Infections
23:38
Athlete's Foot
23:44
Ringworm
24:09
Yeast Infections
24:27
Candidemia
24:56
Aspergillus
25:15
Fungal Meningitis
25:44
Animals, Part I

35m 28s

Intro
0:00
Animal Basics
0:05
Multicellular Eukaryotes
0:12
Motility
0:27
Heterotrophic
0:47
Sexual Reproduction
0:57
Symmetry
1:14
Gut
1:26
Cephalization
1:40
Segmentation
1:53
Sensory Organs
2:09
Reproductive Strategies
3:07
Gonads
3:17
Fertilization
4:01
Asexual
4:53
Animal Development
7:27
Zygote
7:29
Blastula
7:50
Gastrula
9:07
Embryo
12:57
Symmetry
13:17
Radial Symmetry
14:14
Bilateral Symmetry
15:26
Asymmetry
16:34
Body Cavities
17:22
Coelom
17:24
Acoelomates
18:39
Pseudocoelomates
19:15
Coelomates
19:40
Major Animal Phyla
20:47
Phylum Porifera
21:15
Phylum Cnidaria
21:33
Phylum Platyhelmininthes, Nematoda, and Annelida
21:44
Phylum Rotifera
21:56
Phylum Mollusca
22:13
Phylum Arthropoda
22:34
Phylum Echinodermata
22:48
Phylum Chordata
23:18
Phylum Porifera
25:15
Sponges
25:23
Oceanic or Aquatic
26:07
Adults are Sessile
26:26
Structure
27:09
Sexual or Asexual Reproduction
28:31
Phylum Cnidaria
28:49
Sea Jellies, Anemonse, Hydrozoans, and Corals
28:57
Mostly Oceanic
30:42
Body Types
31:32
Cnidocytes
33:06
Nerve Net
34:55
Animals, Part II

48m 42s

Intro
0:00
Phylum Platyhelminthes
0:04
Flatworms
0:14
Acoelomates
0:33
Terrestrial, Oceanic, or Aquatic
0:46
Simple Nervous System
2:46
Reproduction
3:38
Phylum Nematoda
4:20
Unsegmented Roundworms
4:25
Pseudocoelomates
4:34
Terrestrial, Oceanic, or Aquatic
4:53
Full Digestive Tract
5:29
Reproduction
7:07
C. Elegans
7:24
Phylum Annelida
8:11
Segmented Roundworms
8:20
Terrestrial, Oceanic, or Aquatic
8:42
Full Digestive Tract
8:56
Accordion-like Movement
11:26
Simple Nervous System
12:31
Sexual Reproduction
13:40
Class Oligochaeta
14:47
Class Polychaeta
14:56
Class Hirudinea
15:13
Phylum Rotifera
16:11
Pseudocoelomates
16:26
Terrestrial, Aquatic
16:42
Digestive Tract
16:56
Phylum Mollusca
18:55
Snails, Slugs, Clams, Oysters
19:00
Terrestrial, Oceanic, or Aquatic
19:14
Mantle
19:29
Full Digestive Tract with Specialized Organs
21:10
Sexual Reproduction
24:29
Major Classes
24:58
Phylum Arthropoda
28:16
Insects, Arachnids, Crustaceans
28:19
Terrestrial, Oceanic, or Aquatic
28:41
Head, Thorax, Abdomen
28:50
Excretion with Malpighian Tubes
32:48
Arthropod Groups
34:06
Phylum Echinodermata
38:32
Sea Stars, Sea Urchins, Sand Dollars, Sea Cucumbers
38:37
Oceanic or Aquatic
39:36
Water Vascular System
39:43
Full Digestive Tract
40:38
Sexual Reproduction
42:01
Phylum Chordata
42:16
All Vertebrates
42:22
Terrestrial, Oceanic, or Aquatic
42:40
Main Body Parts
42:49
Mostly in Subphylum Vertebrata
44:54
Examples
45:14
Animals, Part III

35m 45s

Intro
0:00
Characteristics of Subphylum Vertebrata
0:04
Vertebral Column
0:16
Neural Crest
0:38
Internal Organs
1:24
Fish Characteristics
2:05
Oceanic or Aquatic
2:16
Locomotion with Paired Fins
3:15
Gills
4:18
Fertilization
8:14
Movement
8:30
Fish Classes
8:58
Jawless Fishes
9:06
Cartilaginous Fishes
10:07
Bony Fishes
10:46
Amphibian Characteristics
12:22
Tetrapods
12:29
Moist Skin
14:22
Circulation
14:39
Nictitating Membrane
16:36
Tympanic Membrane
16:56
External Fertilization is Typical
17:34
Amphibian Orders
18:20
Order Anura
18:27
Order Caudata
19:15
Order Gymnophiona
19:59
Reptile Characteristics
20:31
Dry, Scaly Skin
20:37
Lungs for Gas Exchange
22:00
Terrestrial, Oceanic, Aquatic
22:12
Ectothermic
23:07
Internal Fertilization
24:13
Reptile Orders
26:28
Order Squamata
26:33
Order Crocodilia
27:32
Order Testudinata
27:55
Order Sphenodonta
28:30
Bird Characteristics
28:43
Feathers
29:42
Lightweight Bones
31:33
Lungs with Air Sacs
32:25
Endothermic
33:47
Internal Fertilization
34:03
Bird Orders
34:13
Order Passeriformes
34:29
Order Ciconiiformes
34:46
Order Sphenisciformes
34:55
Order Strigiformes
35:20
Order Struthioniformes
35:25
Order Anseriformes
35:38
Mammals

38m 39s

Intro
0:00
Mammary Glands and Hair
0:04
Class Mammalia Name
0:20
Hair Functions
1:53
Metabolic Characteristics
3:58
Endothermy
4:01
Feeding
4:48
Mammalian Organs
8:43
Respiratory System
8:47
Circulation
9:26
Brain and Senses
10:29
Glands
11:56
Mammalian Reproduction
12:55
Live Birth
13:03
Placental
13:17
Marsupial
14:41
Gestation Periods
16:07
Infraclass Marsupialia
17:42
Australia
17:59
Uterus/ Pouch
18:33
Origins
18:53
Examples
19:24
Order Monotremata
20:21
Egg Layers
20:25
Platypus, Echidna
20:55
Shoulder Area Has a Reptilian Bone Structure
21:07
Order Insectivora
22:21
Insectivores
22:23
Pointy Snouts
22:32
Burrowing
22:53
Examples
23:10
Order Chiroptera
23:32
True Flying Mammalian Order
23:38
Wings
23:59
Feeding
24:21
Examples
25:08
Order Xenarthra
25:14
Edentata
25:18
No Teeth
25:23
Location
25:50
Examples
25:55
Order Rodentia
26:33
40% of Mammalian Species
26:38
2 Pairs of Incisors
26:45
Examples
27:28
Order Lagomorpha
28:06
Herbivores
28:30
Examples
28:41
Order Carnivora
29:19
Teeth
29:36
Examples
29:42
Order Proboscidea
30:37
Largest Living Terrestrial Mammals
30:40
Trunks
30:48
Tusks
31:12
Examples
31:33
Order Sirenia
32:01
Large, Slow Moving Aquatic Mammals
32:15
Flippers
32:26
Herbivores
32:37
Examples
32:42
Order Cetacea
32:46
Large, Mostly Hairless Aquatic Mammals
32:50
Flippers
33:06
Fluke
33:18
Blowhole
33:29
Examples
34:10
Order Artiodactyla
34:30
Even-Toed Hoofed Mammals
34:33
Herbivores
34:37
Sometimes Grouped with Cetaceans
34:52
Examples
35:35
Order Perissodactyla
35:57
Odd-Toed Hoofed Mammals
36:00
Herbivores
36:12
Examples
36:27
Order Primates
36:30
Largest Brain-to-Body Ratio
36:35
Arboreal
37:03
Nails
37:33
Examples
38:29
Animal Behavior

29m 55s

Intro
0:00
Behavior Overview
0:04
Behavior
0:08
Origin of Behavior
0:36
Competitive Advantage
1:26
Innate Behaviors
2:05
Genetically Based
2:07
Instinct
2:13
Fixed Action Pattern
3:31
Learned Behavior
5:13
Habituation
5:26
Classical Conditioning
6:31
Operant Conditioning
7:51
Imprinting
10:17
Learned Behavior That Can Only Occur in a Specific Time Period
10:20
Sensitive Period
10:28
Cognitive Behaviors
11:53
Thinking, Reasoning, and Processing Information
12:02
Examples
12:22
Competitive Behaviors
14:40
Agonistic Behavior
14:46
Dominance Hierarchies
15:23
Territorial Behaviors
16:19
More Types of Behavior
17:05
Foraging Behaviors
17:08
Migratory Behaviors
17:53
Biological Rhythms
19:15
Communication Behaviors
20:37
Pheromones
20:52
Auditory Communication
22:18
Courting and Nurturing Behaviors
23:42
Courting Behaviors
23:45
Nurturing Behaviors
26:04
Cooperative Behaviors
26:47
Benefit All Members of the Group
27:01
Example
27:08
Section 6: Ecology
Ecology, Part I

1h 7m 26s

Intro
0:00
Ecology Basics
0:05
Ecology
0:18
Biotic vs. Abiotic Factors
1:25
Population
2:23
Community
2:45
Ecosystem
3:04
Biosphere
3:27
Individuals and Survival
4:13
Habitat
4:23
Niche
4:37
Symbiosis
7:07
Obtaining Energy
11:14
Producers
11:24
Consumers
13:31
Food Chain
17:11
Model to Illustrate How Matter Moves Through Organisms in an Ecosystem
17:15
Examples
18:31
Food Web
20:29
Keystone Species
22:55
Three Ecological Pyramids
27:28
Pyramid of Energy
27:38
Pyramid of Numbers
31:39
Pyramid of Biomass
34:09
The Water Cycle
37:24
The Carbon Cycle
40:19
The Nitrogen Cycle
43:34
The Phosphorus Cycle
46:42
Population Growth
49:35
Reproductive Patterns
51:58
Life History Patterns Vary
52:10
r-Selection
53:30
K-Selection
56:55
Density Factors
59:02
Density-Dependent Factors
59:29
Density-Independent Factors
1:02:21
Predator / Prey Relationships
1:03:59
Ecology, Part II

50m 50s

Intro
0:00
Mimicry
0:05
Batesian Mimicry
0:38
Müllerian Mimicry
1:53
Camouflage
3:23
Blend In with Surroundings
3:38
Evade Detection by Predators
3:43
Succession
5:22
Primary Succession
5:40
Secondary Succession
7:44
Biomes
9:31
Terrestrial
10:08
Aquatic / Marine
10:05
Desert
11:20
Annual Rainfall
11:24
Flora
13:35
Fauna
14:15
Tundra
14:49
Annual Rainfall
15:00
Permafrost
15:50
Flora
16:06
Fauna
16:40
Taiga (Boreal Forest)
16:59
Annual Rainfall
17:14
Largest Terrestrial Biome
17:33
Flora
18:37
Fauna
18:49
Temperate Grassland
19:07
Annual Rainfall
19:28
Flora
20:14
Fauna
20:18
Tropical Grassland (Savanna)
20:41
Annual Rainfall
21:01
Flora
21:56
Fauna
22:00
Temperate Deciduous Forest
22:19
Annual Rainfall
23:11
Flora
23:45
Fauna
23:50
Tropical Rain Forest
24:11
Annual Rainfall
24:16
Flora
27:15
Fauna
27:49
Lakes
28:05
Eutrophic
28:21
Oligotrophic
28:29
Zones
29:34
Estuaries
32:56
Area Where Freshwater and Salt Water Meet
33:00
Mangrove Swamps
33:12
Nutrient Traps
33:52
Organisms
34:24
Marine
34:50
Euphotic Zone
35:16
Pelagic Zone
37:11
Abyssal Plain
38:15
Conservation Summary
40:03
Biodiversity
40:33
Habitat Loss
44:06
Pollution
44:55
Climate Change
47:03
Global Warming
47:06
Greenhouse Gases
47:48
Polar Ice Caps
49:01
Weather Patterns
50:00
Section 7: Laboratory
Laboratory Investigation I: Microscope Lab

24m 51s

Intro
0:00
Light Microscope Parts
0:06
Microscope Use
6:25
Mount the Specimen
6:28
Place Slide on Stage
7:29
Ensure Specimen is Above Light Source
8:11
Lowest Objective Lens Faces Downward
8:34
Focus on the Image
9:36
Adjust the Nosepiece If Needed
9:49
Re-Focus
9:57
Human Skin Layers
10:42
Plants Cells
13:43
Human Lung Tissue
15:20
Euglena
18:26
Plant Stem
20:43
Mold
22:57
Laboratory Investigation II: Egg Lab

11m 26s

Intro
0:00
Egg Lab Introduction
0:06
Purpose
0:09
Materials
0:37
Time
1:24
Day 1
1:28
Day 2
3:59
Day 3
6:05
Analysis
7:50
Osmosis Connection
10:24
Hypertonic
10:36
Hypotonic
10:49
Laboratory Investigation III: Carbon Dioxide Production

14m 34s

Intro
0:00
Carbon Dioxide Introduction
0:06
Purpose
0:09
Materials
0:56
Time
2:39
Part I
2:41
Put Water in Large Beaker
3:09
Exhale Into the Water
3:15
Add a Drop of Phenolphthalein
4:31
Add NaOH
5:33
Record the Amount of Drops
6:10
Part II
6:24
Add HCL
6:39
Exercise for Five Minutes
7:26
Return and Re-Do the Exhaling
7:58
Analysis
9:11
Aerobic Respiration Connection
13:18
As Aerobic Respiration Occurs In Cells, Carbon Dioxide Is Produced
13:21
Increase Output of Carbon Dioxide
13:29
Number of Exhalations Increase
14:17
Laboratory Investigation IV: DNA Extraction Lab

10m 38s

Intro
0:00
DNA Lab Introduction
0:06
Purpose
0:09
Materials
0:45
Time
2:03
Part I
2:06
Pour Sports Drink Into the Small Cup
2:08
When Time Expires, Spit Into the Cup
2:53
Add Cell Lysate Solution
3:21
Let it Sit for a Couple Minutes
4:04
Part II
4:10
Slowly Add Cold Ethanol
4:13
DNA Will Creep Up Into the Ethanol Layer
5:01
Analysis
5:59
DNA Structure Connection
8:49
DNA is Microscopic
8:54
Visible DNA
9:39
Extracted DNA
9:49
Laboratory Investigation V: Onion Root Tip Mitosis Lab

13m 12s

Intro
0:00
Mitosis Lab Introduction
0:06
Purpose
0:09
Materials
0:57
Time
1:42
Part I
1:49
Mount the Slide and Zoom Into the Root Apical Meristem
1:50
Zoom In
3:00
Count the Cells in Each Phase
3:09
Record Your Results
3:52
Microscope View Example
3:58
Part II
6:49
Move to Another Part of the Root Apical Meristem
6:55
Count the Phases in this Second Region
7:02
Analysis
9:07
Mitosis Connection
11:17
Rate of Mitosis Varies from Species to Species
11:21
Mitotic Rate Was Higher Since We Used An Actively Dividing Tissue
12:16
Laboratory Investigation VI: Inheritance Lab

13m 55s

Intro
0:00
Inheritance Lab Introduction
0:05
Purpose
0:09
Materials
0:53
Time
2:00
Explanation
2:03
Basic Procedure
5:03
Analysis
8:00
Inheritance Laws Connection
11:23
Law of Segregation
11:31
Law of Independent Assortment
12:49
Laboratory Investigation VII: Allele Frequencies

14m 11s

Intro
0:00
Allele Frequencies Introduction
0:05
Purpose
0:08
Materials
1:34
Time
2:10
Part I
2:12
Part II
7:05
Analysis
7:51
Evolution Connection
10:45
Meant to Stimulate How a Population's Allele Frequencies Change Over Time
10:47
Particular Phenotypes Selected
11:31
Recessive Allele Keeps Dropping
12:18
Laboratory Investigation VIII: Genetic Transformation

16m 42s

Intro
0:00
Genetic Transformation Introduction
0:06
Purpose
0:09
Materials
0:57
Time
3:31
Set-Up
4:18
Starter Culture with E. Coli Colonies
4:21
Just E. Coli
5:37
Ampicillin with No Plasmid
6:24
Ampicillin with Plasmid
7:11
Ampicillin with Plasmid and Arabinose
7:33
Procedure
8:35
Analysis
13:01
Genetic Transformation Connection
14:59
Easier to Transform Bacteria Than a Multicellular Organism
15:03
Desired Trait Can be Expressed from the Bacteria
15:52
Numerous Applications in Medicine
16:04
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Laboratory Investigation V: Onion Root Tip Mitosis Lab

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

  • Intro 0:00
  • Mitosis Lab Introduction 0:06
    • Purpose
    • Materials
    • Time
  • Part I 1:49
    • Mount the Slide and Zoom Into the Root Apical Meristem
    • Zoom In
    • Count the Cells in Each Phase
    • Record Your Results
  • Microscope View Example 3:58
  • Part II 6:49
    • Move to Another Part of the Root Apical Meristem
    • Count the Phases in this Second Region
  • Analysis 9:07
  • Mitosis Connection 11:17
    • Rate of Mitosis Varies from Species to Species
    • Mitotic Rate Was Higher Since We Used An Actively Dividing Tissue

Transcription: Laboratory Investigation V: Onion Root Tip Mitosis Lab

Hi, welcome back to www.educator.com. This is the laboratory investigation 5, onion root tip mitosis lab.0000

Here is the introduction, the purpose of this lab is to calculate the amount of time0008

that onion root tip cells spend in the phases of mitosis.0013

If you are wondering why an onion root tip cell?0016

You have these meristems, meristematic tissue in plants, whether it is the apical meristems,0020

at the top and bottom, or the lateral meristems that widen plants.0027

Those are the more actively dividing tissues.0032

They are going through more mitosis events per day.0035

If we want to see a lot more mitosis, we are going to look at those regions.0039

If we are looking at other parts of the plant, like right in the middle of the leaf, you would not see as much mitosis.0043

Looking at this area in an onion root tip, where you can find the root apical meristem, you will see a lot of mitosis.0049

Materials, preserved onion root tips in microscope slides, stained for visibility.0058

As a teacher, that is my favorite thing to do, it was just easy, they are reliable.0063

You know they are going to be visible to students, if they know how to use a microscope.0067

Other teachers, I have actually seen them making the young onions have root growth and then making cross sections themselves.0073

Mounting those tissues on the slide and staining, that takes a lot more work.0082

I guess it would be more rewarding if you do correctly,0087

but I tend to go with the preserved onion root tips that have been there for years.0089

You need a compound light microscope that can go to times 400 magnification, so you get around this close.0096

Time required, about 45 minutes.0102

If you use your time wisely, that is all you need.0106

Part 1, mount the slide, actually get it there.0109

If you are using slices from an actual onion root tip that is alive or get the preserved slide,0115

put it on stage, and zoom into the root apical meristem.0121

The apical meristems, there is the shoot apical meristem and there is a root apical meristem.0125

We are looking at the one at the bottom.0129

Here is what you would see when you actually around times 100.0131

Times 40 that first view to the objective lens, you will be able to more zoom out.0137

Here is what is known as the root cap, this is what you do not want to zoom into.0142

You do not want to zoom into that area.0150

That is more protective cap, it is not actively dividing.0153

You want to zoom into the area up here, there is actually multiple regions,0158

multiple views in these areas, that are going to have some active mitosis.0165

If you look very carefully in the slide, you can see some phase of mitosis.0169

Later on in this lesson, where we zoom in times 400, it is much more visible.0174

You are going to zoom in until you get to that times 400 magnification,0180

that is where you have the appropriate view, you are close enough to really see those phases of mitosis.0185

We may not actually count all the phases, count the cells that are in each phase.0189

Interface, the cells in interphase look like plain old cells.0193

They just have a solid nucleus with a visible nucleolus.0197

During interface, you are between mitotic division, you do not have those visible chromosomes.0202

Prophase is when you have these chromosomes, you can see them condensed.0208

It is still in that nuclear area, they are still bundled together in the center.0212

Metaphase, they are lined up along the equator, the metaphase plate.0217

Anaphase is where they are being pulled apart.0221

Telophase is where you would have those groups of chromosomes towards the poles of the cells, about to be boned up into new nuclei.0224

You are going to record results along with the total number of cells that you actually counted.0232

Here is what we are going to be looking at.0240

When you are zoomed in times 400, you are going to be seeing something like this.0241

This is a typical view, you see about 80 cells.0244

I had a student see anywhere from 70 to 140 cells when they are zoomed in times 400.0249

It really depends on what specific area of the root apical meristem, you are on that specific region because the farther up,0257

the more superior you go, the slightly more elongated the cells are that they look physically bigger and take up more room.0265

This is a good view, you see a lot of things going on.0272

Let me highlights some cells, in terms of what phases they are definitely in.0274

If you look at this, this is definitely an interphase cell.0281

You can see the cell nucleus with a nucleolus inside of it.0291

Prophase, this is a classic prophase.0295

Some people would actually consider this prometaphase.0302

If you are in a more advanced biology class, there will be a lot more talk about prometaphase.0306

It is the phase that is halfway between prophase and metaphase.0309

You can see they are on their way to going to that metaphase plate, to be lined up along the center or the equator.0313

This, I would still consider it prophase for the purposes of this lab.0321

Here is metaphase, you can see they are lined up along the center.0326

Here is metaphase, here is anaphase, you can see how these chromosomes are being pulled to the side, there is anaphase.0330

There is a fine line between anaphase and telophase.0344

Sometimes, when you look get a view, you might not even see any telophase.0351

You may not see any anaphase.0355

It is just a coincidence and what was frozen in time, at that moment.0357

If I flash forward this a little bit further, and you have this bundle kind of more condensed over here but not looking like a new nucleus.0361

This one is a little condensing here but not looking like a complete nucleus, I would say that is definitely telophase.0368

This is close to telophase as well.0373

Actually, this may be a good candidate for telophase.0376

It looks like it is at its end, it is really a judgment call.0379

That is why this lab is only reliable, depending on who is looking into view and who is doing the counting.0385

Mistakes can be made, in terms of saying all that was definitely telophase, that was anaphase, and vice versa.0390

The more data you have, the more times you do this and average out the results,0396

the more accurate your figures are probably going to be.0401

What you will do is you add up all the numbers here and I will give you an example on the next slide.0404

Part 2, in terms of getting more reliable results, you can move to another part of the root apical meristem,0411

another view, or use another root tip, a completely different root tip.0417

Zoom in times 400 again and once again, count the phases, from interphase to telophase in the second region.0421

You can do it the third time, if you want.0427

Average the numbers to maximize your accuracy.0429

Divide those numbers for each phase by the total number of cells to approximate the percentage of time you spent in each phase.0432

Let me give you an example.0439

Here is interphase, prophase, metaphase, anaphase, telophase, and here is the total.0442

Let us say with view 1, we got 52 for interphase.0454

Let us say that for prophase we get 10, metaphase we saw 4, anaphase we saw 8, and telophase we saw 6.0461

The total ends up being 80.0474

We need to get the percentages, in terms of the relative amount of time based on this data that cells are spending in a various phase.0478

If we divide 52 by 80, that gives you 65%.0485

10 divided by 80, 12.5%, 4 divided by 80 is 5%.0492

8 divided by 80 is 10%, and 6 would be 7.5.0501

It adds up to 100%.0508

If you do this again, you look at a second view and count up all those cells.0511

You may get 70 cells in interphase which would, if you average out the data0516

that would increase your percentage of interphase, closer to 70%.0522

In the second view, you may actually have less prophase, you may have less telophase or more anaphase.0527

Like I said, the more lab groups that are doing this, the more views you look at over the microscope, the more cells you are counting.0533

As you average those things out, you get more reliable data, in terms of what is actually going on with the meristematic tissue.0541

Analysis, how effective is the method of counting cells.0549

Like I hinted earlier, it depends, it depends on the student or teacher knowledge of precisely what cells are in what phases.0552

Sometimes, it is a judgment call, sometimes it is like literally in between prophase and metaphase.0560

You can count prometaphase, if you want, as a separate phase.0566

It is in between anaphase and telophase, you just have to pick one or the other.0569

In the end, you are just learning from this experience, in terms of getting a sense of0573

what the cells are doing and what they look like in this different phases of mitosis.0578

Since, these cells are dead, the ones I would be using, it will be frozen in time at the living tissue.0583

Would it be better to go with living tissue?0589

Not necessarily, there are advantages with using these preserved tissues.0592

If you were to buy all of these actual live onion root tips and plan on doing the slices and making them thin enough0598

and staining them, there is room for error, in terms of not doing it correctly or not having thin enough slices,0608

and being able to visualize the chromosomes.0614

Having them preserved, these preserved dead tissues from formally living onion root tips,0617

in terms of being able to see what is going on in there.0625

Also, you do not have to worry about movement.0630

When they have been sliced, the relative amount of movement and activity may be hampered,0634

maybe inhibited a bit because of you have cut through them and probably damaged some cells in the process.0639

There are some advantages to using the preserved tissues.0648

How can you make this more accurate or reliable?0651

Like I hinted before, more groups doing more counting or if you are doing this by yourself, do 8 views.0654

Those little errors, in terms of you did not see any telophase, maybe there was a telophase you just did not see it.0662

Or did not know that anaphase is actually telophase.0669

Those little errors will become less problematic, the more data you have.0671

The connection to mitosis as a whole, the rate of mitosis varies from species to species, and tissue to tissue.0678

There are parts of your body where cells are not dividing at all.0686

There are plenty of parts in the brain, in your skeletal muscles, or cells that I’m going to call G0.0689

A phase that is basically exit or out of the cell cycle.0694

It is not going to have active cell division throughout the life of the cell.0697

There are other parts of the body, specially your skin, the membranes within your digestive tract that have to divide,0702

specially if they are being damaged over time or subjected to friction.0709

It varies species to species, two different plants can have completely different mitotic rates.0714

Within one plant or one animal, like I said, using the meristem, more actively dividing tissue,0720

less percentage of interphase relative to mitosis.0727

There are other parts of the plants where interphase is closer to 100% of the time because the cells are not dividing.0730

Since we are using actively dividing tissue, their relative mitotic rate was higher.0736

The amount of time spent in interphase was lower.0742

That is what the meristem is doing, lots of cell division, a lot more of the m or mitotic part of the cell cycle.0745

Comparing this data to meristematic tissues from other plants, will be revealing.0753

Do onions actually have faster dividing cells than the root apical meristems of other plants?0758

I know the answer to that but it is certainly worth investigating.0768

Here is a lovely view of a plant cell from another plant.0771

Presumably, this is not actively dividing but I like this view, I think it is it is gorgeous.0775

You can see all those lovely chloroplasts.0781

With this lab and others, just reveals the intricacies and lovely things going on with living beings.0783

Thank you for watching www.educator.com.0791

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