Hierarchy of Biology Tables

Sickle Cell Anemia - Macromolecule

Point mutation in the Beta Globin gene (substitution of valine for glutamic acid) - fibre mutation.

Sickle Cell Anemia - Organelle

Mutated protein travels protein production pathways (valine is hydrophobic).

Sickle Cell Anemia - Cell

Sickle cell; takes 10-20 days to clear (whereas normal blood cells take 120 days to clear).

Sickle Cell Anemia - Organ / Organ System

Sickled cell can block small blood vessels and block the movement of oxygen-carrying blood.

Sickle Cell Anemia - Organism

Anemia, pain crisis, stroke, jaundice.

Sickle Cell Anemia - Population

1/12 African descent; high incidence in areas where malaria is high because of heterozygote advantage.

CCR5 Delta 32 - Macromolecule

CC Chemokine receptor 5 (CCR5); 32 base pair deletion in the coding region; result is a nonfunctional protein.

CCR5 Delta 32 - Organelle

Protein receptor does not reach the cell surface.

CCR5 Delta 32 - Cell

CCR5 receptor is missing. HIV-1 entry is impaired in homozygotes because of missing co-receptor.

CCR5 Delta 32 - Organ / Organ System

HIV can’t infect cells; no subsequent T cell deaths.

CCR5 Delta 32 - Organism

Homozygotes are immune to HIV subtype.

CCR5 Delta 32 - Population

Higher prevalence of this mutation in Northern European descent; selective pressure remains unknown.

CFTR - Macromolecule

Membrane bound protein (chlorine channel); More than 2500 mutations (ranging in severity). F508del is the most common.

CFTR - Organelle

Mutated protein sometimes reaches cell surface, sometimes targeted for degradation (dependent on mutation).

CFTR - Cell

Less functional/no chloride channel at cell membrane; Other channels don’t work properly.

CFTR - Organ / Organ System

Mucus builds up in lungs, salty sweat, lack of pancreatic enzymes.

CFTR - Organism

Coughing, poor growth, lung infections, early death.

CFTR - Population

1/20 are carries from Eastern descent (high incidence); Possibly decreases severity of cholera.

Lactase Permanence - Macromolecule

Lactase is the enzyme responsible for the digestion of the milk sugar lactose and its production decreases after the weaning phase in most mammals. European population: a single mutation (-13910*T).

Lactase Permanence - Cell

Continues to produce lactase past the weaning stage.

Lactase Permanence - Organism

Can digest milk and obtain nutrients and energy from dairy.

Lactase Permanence - Population

Different mutations in Africa, Europe, and Middle East. It has evolved multiple times - example of convergent evolution and human gene-culture coevolution.

Rubric for Experimental Design

1. Hypothesis / Prediction

2. Control(s) (what is kept constant?)

3. Independent and dependent variables (variables that you can change)

4. How independent and dependent variables are manipulated

5. Hold other variables constant

6. Replicates (how is the experiment replicated?)

7. Repeated (how many times is the experiment repeated?)

8. Awareness that one can never prove a hypothesis

9. Ethics

10. Confounding effects / Bias