Biology

Describe four of the characteristics of life that distinguish these plants from the dead stones they mimic. 1.) You are investigating a single-celled eukaryotic plant cell and the bacteria that live inside it. What organelles will you observe in both organisms? Give a specific explanation for your answer.   2.) Imagine that certain warblers exhibit […]

Exercise 3 – DNA fingerprints of unknown DNA samples You must work with a partner on this exercise. Step 1: Loading the gel. Obtain a sealed E-Gel from a lab instructor. Plug in the power base at your carrel. Open the package and insert the E-gel into the power base. The E-gel is inserted right

Exercise 2 – Practice using pipettes to load wells Loading DNA samples into the tiny wells of a thin gel is a delicate operation and requires practice. If a well is punctured by the pipette, the sample will drain out and be lost. In the Central Study Area obtain a petri dish filled with agar

Exercise 1 – extraction DNA from cells Summary of extraction method: Onion cells are difficult to lyse (rupture) because plant cells are surrounded by a cell wall (a tough barrier made of cellulose). (1) Breaking up the onion in a blender helps to release the cellular contents. (2) The chopped material is then mixed with

Why are the distances between the cuts so different in different people? In 1986, Alec Jeffreys, a geneticist in England, was studying introns – stretches of DNA located in between the genes. Introns are sequences of “nonsense” or “junk” DNA that do not code for a specific protein. Jeffreys found that some introns are made

PART I: DNA FINGERPRINTING DNA fingerprinting has many applications. It is now routinely used to test samples of blood, hair, saliva and semen left at crime scenes. The results are compared to those of a suspect to establish the individual’s guilt. DNA fingerprinting can also be used to establish familial relationships in paternity cases, to

Exercise 5 – The effect of the color of light on the rate of photosynthesis Green leaves look green not because they absorb green light, but because they reflect green light to our eyes. A pigment’s absorption spectrum (Figure 3) quantifies graphically how much of each color (wavelength) the pigment absorbs. Chlorophyll a and chlorophyll

Exercise 4 – The effect of carbon dioxide and pH on the rate of photosynthesis 1. Use a cork borer to cut 100 or more leaf disks from a spinach leaf (spinach is rich in chloroplasts). Cut to either side of the largest leaf veins, not through them. Discard any disks that are bruised or

PART III: FACTORS AFFECTING THE RATE OF PHOTOSYNTHESIS In this section you and you partner(s) will do experiments to test the influence of two environmental factors on the rate of photosynthesis. Possible factors affecting photosynthetic rate Your experience with enzyme-catalyzed reactions from minicourse 2 suggest a number of factors that might influence the rate of

PART II: STRUCTURAL ORGANIZATION OF LEAVES 9.2 Exercise 2 – Internal features of a leaf All the structures of the leaf can be understood in terms of their role in maximizing the efficiency with which the chloroplasts carry out photosynthesis in different habitats. As you study the structures below, ask yourself, “How does this structure