History of Evolutionary Thought:
I. Scientific Method
● Science is a process or means of knowing and learning about the world
1. Observations
- Propose questions
- Perform background research
2. Hypotheses
- select/develop models
- Design experiments
3. Controlled Experiment
- Check experimental results for reproducibility
- Analyze data and compare their behavior with predictions
4. Conclusion
- Determine if data supports or disproof hypotheses
- Determine how conclusions fit in with other information
● Hypotheses v Theory v Law
1. Hypothesis
- A testable explanation for a phenomenon
- May be based on small sets of previously observed data
2. Theory
- A well-sustained explanation of some aspect of the natural world
that can incorporate facts, laws, inferences, and tested
hypotheses
- Accepted by most practitioners in the field, has already been
tested many times
3. Law
- A descriptive generalization about how some aspect of the natural
world behaves under stated circumstances
- In very few conditions are these types of laws broken
Cell Biology and DNA:
Why is this important?
- Building blocks to larger concepts in course such as
● Variations between individuals
● Change in traits as they are inherited through generations
Cells: the fundamental unit of life
- Prokaryotes (first cell on earth)
● Starting point
● No nucleus
- Eukaryotes
● Animal cell
● Contains genetic information that controls cell function
● Contains nucleus
- Organelles
, ● Nucleus
- Contains genetic information that controls the cell’s function
● Mitochondria
- Contains the organelles, which are involved in activities related to the
function of cell and organism
● Ribosomes
- Essential to the manufacture of proteins
● Cytoplasm
- Produce energy for the cell
- Contain their own DNA, mitochondrial DNA
- Back to DNA and the nucleus
● Chromosomes
- Composed of DNA and proteins
- coiled or uncoiled at different times
- Chromosomes (two main types)
● Autosomes: determine traits other than sex
- 22 pairs (in humans)
● Sex chromosomes: determines sex
- 1 pair (in humans)
- Each parent only gives half
● Gametes aka germ cells: reproductive cells, sperm, and eggs (ova)
- Haploid (23 chromosomes)
● Somatic cells make up your body
- Diploid (46 chromosomes)
- Processes that lead to the production of somatic (body) cells and gametes:
● Mitosis: growth and repair, one replication one division, daughter cells identical to
parent cell (somatic)
- “Simple cell division”
- Cell replicates then divide once to create two identical daughter cells
● Meiosis: reproduction, one replication, two divisions, daughter cells not identical
to parent (gametes)
- Begins with one diploid cell
- replication, and then two divisions
- 4 cells with half genetic material
- Chromosomes are often depicted as two identical copies still connected to each other.
Vocabulary:
- Homologous chromosomes: pairs that code for the same traits
- Locus: the specific location of a gene
- Gene: segment of DNA, with genetic information for a particular trait
- Centromere: (the center) the part of the chromosome that links “sister chromatids”
Recombination occurs during meiosis
- The exchange of genetic material between paired (homologous) chromosomes
, Significance of recombination
- A key mechanism for increasing genetic diversity
- Does not produce new variants of genes
Some differences between the sexes
- Of the four gametes produced by females (eggs/ova), usually only one is viable
● The other 3 are known as polar bodies
- Gametes produced by males (sperm) contain very few molecules of mitochondrial DNA
● During fertilization process, it would often break off
● Typically mtDNA does not enter fertilized egg
● Therefore, mtDNA is only inherited from the mother
Problems/Errors:
- Nondisjunction: one daughter cell gets two copies of the same chromosome, while the
other gets none
● Autosome→ trisomy 21 (down syndrome)
● Sex chromosome→ Klinefelter syndrome, Turner syndrome
● Typically males could get the syndrome
● Turner syndrome is more recognizable during growth
- During coiling, the gene could invert or turn upside down
- Could happen at random or could be a medical issue
Karyotypes are useful for detecting obvious abnormalities in chromosome numbers
A closer look at DNA:
- DNA: “code” for all the proteins involved in all the structures and chemical reactions that
take place in the cell
● Deoxyribonucleic Acid
● Double helix structure
● Structure of DNA
● Half of one side includes phosphate compound, sugar, and base
- Sugar and phosphate link together for a chain
- Two base types (purines and pyrimidines)
- Purine (guanine and adenine)
- Pyrimidines (cytosine and thymine)
- Guanine (G) → Cytosine (C)
- Adenine (A) → Thymine (T)
Replication
1. The DNA molecule “unzips” - bonds between bases are broken
2. The sides separate into two replication templates
3. “Free-floating” nucleotides are attracted to the templates
4. Two new, identically DNA molecules are formed
Proteins
- Large macromolecules made up of long chains of amino acids
- Functions include metabolic reactions, stimuli response, transporting molecules,
structure (collagen and elastin, etc.)
Amino acids
- 20 different amino acids
I. Scientific Method
● Science is a process or means of knowing and learning about the world
1. Observations
- Propose questions
- Perform background research
2. Hypotheses
- select/develop models
- Design experiments
3. Controlled Experiment
- Check experimental results for reproducibility
- Analyze data and compare their behavior with predictions
4. Conclusion
- Determine if data supports or disproof hypotheses
- Determine how conclusions fit in with other information
● Hypotheses v Theory v Law
1. Hypothesis
- A testable explanation for a phenomenon
- May be based on small sets of previously observed data
2. Theory
- A well-sustained explanation of some aspect of the natural world
that can incorporate facts, laws, inferences, and tested
hypotheses
- Accepted by most practitioners in the field, has already been
tested many times
3. Law
- A descriptive generalization about how some aspect of the natural
world behaves under stated circumstances
- In very few conditions are these types of laws broken
Cell Biology and DNA:
Why is this important?
- Building blocks to larger concepts in course such as
● Variations between individuals
● Change in traits as they are inherited through generations
Cells: the fundamental unit of life
- Prokaryotes (first cell on earth)
● Starting point
● No nucleus
- Eukaryotes
● Animal cell
● Contains genetic information that controls cell function
● Contains nucleus
- Organelles
, ● Nucleus
- Contains genetic information that controls the cell’s function
● Mitochondria
- Contains the organelles, which are involved in activities related to the
function of cell and organism
● Ribosomes
- Essential to the manufacture of proteins
● Cytoplasm
- Produce energy for the cell
- Contain their own DNA, mitochondrial DNA
- Back to DNA and the nucleus
● Chromosomes
- Composed of DNA and proteins
- coiled or uncoiled at different times
- Chromosomes (two main types)
● Autosomes: determine traits other than sex
- 22 pairs (in humans)
● Sex chromosomes: determines sex
- 1 pair (in humans)
- Each parent only gives half
● Gametes aka germ cells: reproductive cells, sperm, and eggs (ova)
- Haploid (23 chromosomes)
● Somatic cells make up your body
- Diploid (46 chromosomes)
- Processes that lead to the production of somatic (body) cells and gametes:
● Mitosis: growth and repair, one replication one division, daughter cells identical to
parent cell (somatic)
- “Simple cell division”
- Cell replicates then divide once to create two identical daughter cells
● Meiosis: reproduction, one replication, two divisions, daughter cells not identical
to parent (gametes)
- Begins with one diploid cell
- replication, and then two divisions
- 4 cells with half genetic material
- Chromosomes are often depicted as two identical copies still connected to each other.
Vocabulary:
- Homologous chromosomes: pairs that code for the same traits
- Locus: the specific location of a gene
- Gene: segment of DNA, with genetic information for a particular trait
- Centromere: (the center) the part of the chromosome that links “sister chromatids”
Recombination occurs during meiosis
- The exchange of genetic material between paired (homologous) chromosomes
, Significance of recombination
- A key mechanism for increasing genetic diversity
- Does not produce new variants of genes
Some differences between the sexes
- Of the four gametes produced by females (eggs/ova), usually only one is viable
● The other 3 are known as polar bodies
- Gametes produced by males (sperm) contain very few molecules of mitochondrial DNA
● During fertilization process, it would often break off
● Typically mtDNA does not enter fertilized egg
● Therefore, mtDNA is only inherited from the mother
Problems/Errors:
- Nondisjunction: one daughter cell gets two copies of the same chromosome, while the
other gets none
● Autosome→ trisomy 21 (down syndrome)
● Sex chromosome→ Klinefelter syndrome, Turner syndrome
● Typically males could get the syndrome
● Turner syndrome is more recognizable during growth
- During coiling, the gene could invert or turn upside down
- Could happen at random or could be a medical issue
Karyotypes are useful for detecting obvious abnormalities in chromosome numbers
A closer look at DNA:
- DNA: “code” for all the proteins involved in all the structures and chemical reactions that
take place in the cell
● Deoxyribonucleic Acid
● Double helix structure
● Structure of DNA
● Half of one side includes phosphate compound, sugar, and base
- Sugar and phosphate link together for a chain
- Two base types (purines and pyrimidines)
- Purine (guanine and adenine)
- Pyrimidines (cytosine and thymine)
- Guanine (G) → Cytosine (C)
- Adenine (A) → Thymine (T)
Replication
1. The DNA molecule “unzips” - bonds between bases are broken
2. The sides separate into two replication templates
3. “Free-floating” nucleotides are attracted to the templates
4. Two new, identically DNA molecules are formed
Proteins
- Large macromolecules made up of long chains of amino acids
- Functions include metabolic reactions, stimuli response, transporting molecules,
structure (collagen and elastin, etc.)
Amino acids
- 20 different amino acids
