LABORATORY 1. DIFFUSION AND OSMOSIS

OVERVIEW

In this laboratory you will investigate the process of diffusion and osmosis in a model of a membrane system. You also will investigate the effect of solute concentration on water potential as it relates to living plant tissues.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• the mechanisms of diffusion and osmosis and their importance to cells
• the effects of solute size and concentration gradients on diffusion across selectively permeable membranes
• the effects of a selectively permeable membrane on diffusion and osmosis between two solutions separated by the membrane
• the concept of water potential
• the relationship between solute concentration and pressure and the water potential of a solution
• the concept of molarity and its relationship to osmotic concentration

Section B: After doing this laboratory you should be able to:

• measure the water potential of a solution in a controlled experiment
• determine the osmotic concentration of living tissue or an unknown solution from experimental data
• describe the effects of water gain or loss in animal and plant cells
• relate osmotic potential to solute concentration and water potential

LABORATORY 2. ENZYME CATALYSIS

OVERVIEW

In this laboratory you will measure the amount of product generated and then calculate the rate of conversion of hydrogen peroxide (H₂O₂) to water and oxygen gas by the enzyme catalase.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• the general functions and activities of enzymes
• the relationship between the structure and function of enzymes
• the concepts of initial reaction rates of enzymes
• how the concept of free energy relates to enzyme activity
• how pH relates to enzyme activity
• that changes in temperature, pH, enzyme concentration, and substrate concentration can affect the initial reaction rates of enzyme-catalyzed reactions

Section B: After doing this laboratory you should be able to:

• measure the effects of changes of temperature, pH, enzyme concentration, and substrate concentration on reaction rates of an enzyme-catalyzed reaction in a controlled experiment
• explain how environmental factors affect the rate of enzyme-catalyzed reactions

LABORATORY 3. MITOSIS AND MEIOSIS

OVERVIEW

Exercise 3A is a study of mitosis. You will use prepared slides of onion root tips to study plant mitosis and to calculate the relative duration of the phases of mitosis in the meristem of root tissue. Prepared slides of the whitefish blastula will be used to study mitosis in animal cells and to compare animal mitosis and plant mitosis

Exercise 3B is a study of meiosis. You will simulate the stages of meiosis by using chromosome models. You will study the crossing over and recombination that occurs during meiosis. You will observe the arrangements of ascospores in the asci from a cross between wild type and mutants for tan spore coat color in the fungus Sordaria fimicola. These arrangements will be used to estimate the percentage of crossing over that occurs between the centromere and the gene that controls that tan spore color.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• the key mechanical and genetic differences between meiosis and mitosis
• the events of mitosis in animal and plant cells
• the events of meiosis (gametogenesis) in animal and plant cells

Section B: After doing this laboratory you should be able to:

• recognize the stages of mitosis in a plant or animal cell
• calculate the relative duration of the cell cycle stages
• describe how independent assortment and crossing over can generate genetic variation among the products of meiosis
• use chromosome models to demonstrate the activity of chromosomes during Meiosis I and Meiosis II
• relate chromosome activity to Mendelian segregation and independent assortment
• calculate the map distance of a particular gene from a chromosome's center for between two genes using an organism of your choice in a controlled experiment
• demonstrate the role of meiosis in the formation of gametes using an organism of your choice, in a controlled experiment
• compare and contrast the results of meiosis and mitosis in plant cells
• compare and contrast the results of meiosis and mitosis in animal cells

LABORATORY 4. PLANT PIGMENTS AND PHOTOSYNTHESIS

OVERVIEW

In this laboratory you will separate plant pigments using chromatography. You also will measure the rate of photosynthesis in isolated chloroplasts. The measurement technique involves the reduction of the dye, DPIP. The transfer of electrons during the light-dependent reactions of photosynthesis reduces DPIP and changes its color from blue to colorless.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• how chromatography separates two or more compounds that are initially present in a mixture
• the process of photosynthesis
• the function of plant pigments
• the relationship between light wavelength or light intensity and photosynthetic rate

Section B: After doing this laboratory you should be able to:

• separate pigments and calculate their Rf values
• describe a technique to determine photosynthetic rates
• compare photosynthetic rates at different temperatures, different light intensities, and different wavelengths of light in a controlled experiment
• explain why the rate of photosynthesis vary under different environmental conditions

LABORATORY 5. CELL RESPIRATION

OVERVIEW

Seeds are living but dormant. When conditions necessary to begin growth are achieved, germination occurs, cellular reactions are accelerated, and the rate of respiration greatly increases. In this laboratory you will measure oxygen consumption during respiration as the change in gas volume in respirometers containing either germinating or nongerminating peas. In addition, you will measure the respiration of these peas at two different temperatures.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• how a respirometer works in terms of the gas laws
• the general process of metabolism in living organisms

Section B: After doing this laboratory you should be able to:

• test the effects of temperature on the rate of cell respiration in ungerminated versus germinated seeds in a controlled experiment
• calculate the rate of cell respiration from experimental data
• relate gas production to respiration rate

LABORATORY 6. MOLECULAR BIOLOGY

OVERVIEW

In this laboratory, you will investigate some basic principles of genetic engineering. Plasmids containing specific fragments of foreign DNA will be used to transform Escherichia coli cells, conferring antibiotic (ampicillin) resistance. Restriction enzyme digests of phage lambda DNA also will be used to demonstrate techniques for separating and identifying DNA fragments using gel electrophoresis.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• how gel electrophoresis separates DNA molecules present in a mixture
• the principles of bacterial transformation
• the conditions under which cells can be transformed
• the process of competent cell preparation
• how a plasmid can be engineered to include a piece of foreign DNA
• how plasmid vectors are used to transfer genes
• how antibiotic resistance is transferred between cells
• how restriction endonucleases function
• the importance of restriction enzymes to genetic engineering experiments

Section B: After doing this laboratory you should be able to:

• use plasmids as vectors to transform bacteria with a gene for antibiotic resistance in a controlled experiment
• demonstrate how restrictions enzymes are used in genetic engineering
• use electrophoresis to separate DNA fragments
• describe the biological process of transformation in bacteria
• calculate transformation efficiency
• be able to use multiple experimental controls
• design a procedure to select positively for antibiotic resistant transformed cells
• determine unknown DNA fragment sizes when given DNA fragments of known size

LABORATORY 7. GENETICS OF ORGANISMS

OVERVIEW

In this laboratory, you will use fruit flies to do genetic crosses. You will learn how to collect and manipulate fruit flies, collect data from F1 and F2 generations, and analyze the results from a monohybrid, dihybrid, or sex-linked cross.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• chi-square analysis of data
• the life cycle of diploid organisms useful in genetics studies

Section B: After doing this laboratory you should be able to:

• investigate the independent assortment of two genes and determine whether the two genes are autosomal or sex-linked using a multi-generation experiment
• analyze the data from your genetic crosses chi-square analysis techniques

LABORATORY 8. POPULATION GENETICS AND EVOLUTION

OVERVIEW

In this activity, you will learn about the Hardy-Weinberg law of genetic equilibrium and study the relationship between evolution and changes in allele frequency by using your class as a sample population.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• how natural selection can alter allelic frequencies in a population
• the Hardy-Weinberg equation and its use in determining the frequency of alleles in a population
• the effects on the allelic frequencies of selection against the homozygous recessive or other genotypes

Section B: After doing this laboratory you should be able to:

• calculate the frequencies of alleles and genotypes in the gene pool of a population using the Hardy-Weinberg formula
• discuss natural selection and other causes of microevolution as deviations from the conditions required to maintain Hardy-Weinberg equilibrium

LABORATORY 9. TRANSPIRATION

OVERVIEW

In this laboratory, you will apply what you learned about water potential from Laboratory 1 (Diffusion and Osmosis) to the movement of water within the plant. You will measure transpiration under different laboratory conditions. You also will study the organization of the plant stem and leaf as it relates to these processes by observing sections of tissue.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• how water moves from roots to leaves in terms of physical/chemical properties of water and the forces provided by differences in water potential
• the role of transpiration in the transport of water within a plant
• the structures used by plants to transport water and regulate water movement

Section B: After doing this laboratory you should be able to:

• test the effects of environmental variables on rates of transpiration using a controlled experiment
• make thin section of stem, identify xylem and phloem cells, and relate the function of these vascular tissues to the structures of their cells

LABORATORY 10. PHYSIOLOGY OF THE CIRCULATORY SYSTEM

OVERVIEW

In Exercise 10A, you will learn how to measure blood pressure. In Exercise 10B, you will measure pulse rate under different physiological conditions: standing, reclining, after the baroreceptor reflex, and during and immediately after exercise. The blood pressure and pulse rate will be analyzed and related to a relative fitness index. In Exercise 10C, you will measure the effect of temperature on the heart rate of the water flea, Daphnia magna.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• the relationship between temperature and rates of physiological processes
• basic anatomy of various circulatory systems

Section B: After doing this laboratory you should be able to:

• measure heart rate and blood pressure in a human volunteer
• describe the effect of changing body position on heart rate and blood pressure
• explain how exercise changes heart rate
• determine a human's fitness index
• analyze pooled cardiovascular data
• discuss and explain the relationship between heart rate and temperature

LABORATORY 11. ANIMAL BEHAVIOR

OVERVIEW In this laboratory, you will observe the behavior of an insect and design an experiment to investigate its responses to environmental variables. You also will observe and investigate mating behavior.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• the concept of distribution of organisms in a resource gradient
• the difference between a kinesis and a taxis

Section B: After doing this laboratory you should be able to:

• measure the effects of environmental variables on habitat selection in a controlled experiment
• describe the different types of insect mating behaviors

LABORATORY 12. DISSOLVED OXYGEN AND AQUATIC PRIMARY PRODUCTIVITY

OVERVIEW In Exercise 12A, you will measure and analyze the dissolved oxygen concentration in water samples at varying temperatures. In Exercise 12B, you will measure and analyze the primary productivity of natural waters or laboratory cultures as a function of light intensity.

OBJECTIVES

Section A: Before doing this laboratory you should understand:

• the biological importance of carbon and oxygen cycling in ecosystems
• how primary productivity relates to the metabolism of organisms in an ecosystem
• the physical and biological factors that affect the solubility of gasses in aquatic ecosystems
• the relationship between dissolved oxygen and the process of photosynthesis and respiration as they affect primary productivity

Section B: After doing this laboratory you should be able to:

• measure primary productivity based on changes in dissolved oxygen in a controlled experiment
• investigate the effects of changing light intensity and/or inorganic nutrient concentrations on primary productivity in a controlled experiment