By considering the genotypes in a single generation (NOT changes in frequencies over time or changes from one generation to the next), how would you show that natural selection is occurring in the Near-Lethal Homozygote (near-lethal recessive) simulation (Hint: think about Hardy-Weinberg Equilibrium).

Which vertebrate group typically has smaller respiratory surfaces than mammals and why?
please explain

• Antibiotic Resistance
  • What factors cause it?
  • How is it happening so fast?
  • Why are some drugs becoming obsolete?
• Horizontal Gene Transfer
  • What, how & why are bacteria able to pick up "Resistant" genes from other bacteria?

Small populations of flies that had three genotypes/phenotypes for eye color (red,orange, and white) were observed over several generations under laboratory controlled conditions (all the same for the samples). Over time the diversity in many of the populations changed from flies of three colors to flies of one color, inevitably red or white, but never the heterozygous condition of orange. These observations suggest a. Natural Selection, red or white eyes were more adaptive. b. Sexual Selection, the females were not attracted to orange eyes. c. Genetic Drift, fixation happen rapidly in these small populations.

Under which circumstances would a muscle cell be undergoing -oxidation instead of glycolysis? Select all correct answers.

a. Cellular ATP levels are low

b. O2 is limited

c. O2 is abundant

d. Cellular ATP levels are high

e. Blood glucose levels are low

explain how this relationship between niche overlap, phylogenetic relationship , and competition would lead to the prediction that competitive exclusion of one species by another is more likely when two species are close relatives.

1). In the event of a eukaryotic pathogen, discuss a way that you could potentially treat the pathogen while minimizing damage to the eukaryotic cells of the host? 1a). How (mechanism of action) does broad spectrum antibiotics disrupt the bacterial cell wall using its Beta-Lactam structure?

4. A culture of bacteria growing at 37°C was shifted to 25°C. How would you expect this shift to alter the fatty acid composition of the membrane phospholipids? Explain. If bacteria were able to synthesize cholesterol, how would you expect this shift to alter their membrane’s cholesterol concentration?

BIO 474 Mid Term Review

1) Describe attributes of the active transport of ions and, specifically, characteristics of the electrogenic Na - K pump. How does active transport maintain homeostasis?

2) Describe the ionic basis of the resting potential and briefly outline the derivation of the Nernst potential. What are typical Nernst potentials for K+, Na+, Cl-, and Ca++? What influences might these potentials have on ionic currents in neurons?

3) Describe the voltage-clamp, how it is used to investigate voltage-dependent phenomena like the action potential. What are the membrane mechanisms (citing evidence) underlying the various "magical" properties fo the action potential?

4) Describe the unitary signal-channel events that can be recorded with patch-clamp electrodes. Name techniques for recording currents from single ion channels? How are those events related to membrane proteins (e.g. associated with the action potential) and to the large net currents recorded in standard voltage - clamp records?

5) Describe the evidence for quantal release of neurotransmitter at the neuromuscular junction, including those involving calculations of number molecules released.

6) Describe the following synaptic phenomena: adaptation, desensitization, facilitation, Post-tetanic potentiation, Neuromodulation. Describe the following modes of neural integration: spatial and temporal summation, convergence/divergence, feedback inhibition and excitation, reciprocal inhibition, and serial/parallel processing.

7) Draw and describe a cellular model for associative learning in some molecular detail. List 6 ways neurons can change PRE - synaptic and/or Post - synaptic actions/responses.

Using Venn diagram, compare the following groups of animals based on similarities and differences. Reptiles and Amphibians

1. Reptiles and Amphibians
2. Vertebrates and Invertebrates
3. Birds (Aves) and Mammals
4. Free living and Sessile