Bio 104 So Far How Science Gets Done

Bio 104 So Far • How Science Gets Done • Arabidopsis as a Model Organism – To study growth and development under different environmental conditions (stimulus…. response) – Adaptations to environments around the globe – Ecotypes and speciation process – Effects of genetic mutations ** – Plant physiology ** – Experimental design and the scientific method

So Far • Cell metabolism and macromolecules • Dr. Moeller’s lectures: Origins and Diversity of Life on Earth – Environmental conditions over geologic time: • Temperature, oxygen, carbon dioxide, water, solar radiation – Changes conditions over time accompanied by changes in living things that were able to change rapidly enough through the process of natural selection – If changes are too rapid for organisms to adapt…. . . Extinction!

What’s Next? • Communicate results of our 6 experiments in scientific poster format • Work with Animals! – Humans, crocs, gators, turtles, and African Clawed Toads! – Physiology and behavior – Stimulus and response – Homeostasis of – Body temperature = thermoregulation • Reminder: testing ideas for use in Fall 2009 Bio 150 course with 225 students

Lab This Week: 1) Record and Analyze Electrocardiograms 2) Diagnose abnormal Electrocardigrams • Future Labs: Record electrocardiograms from crocs, gators, and turtles • The question: Do changes in environmental temperature or metabolism affect heart rate?

Homeostasis: • The relative constancy of the internal environment • Steady state vs. equilibrium

The body: A society of interdependent cells, each type with its own needs and contributions. Humans have ~200 cell types

O 2 List parameters Steady state Vs Equilibrium SET POINT

Invasive vs Non-invasive measurements Cell Membrane: selectively permeable Capillaries: highly permeable except to proteins

Homeostasis • Regulated via reflex arcs and naturally maintained by the process of negative feedback • Measurements – Which physiological variables? – Averages and ranges