II. Gone with the wind: Seed dispersal Dispersal of seeds is very…
Question Answered step-by-step II. Gone with the wind: Seed dispersal Dispersal of seeds is very… II. Gone with the wind: Seed dispersal Dispersal of seeds is very important for the survival of plant species. If seeds germinate too close to their mother plant, they have to compete for light, water, and nutrients from the soil. Seed dispersal allows plants to spread out from a wide area and avoid competing with one another for the same resources. Seeds are dispersed in several different ways. In flowering plants, one or more seeds are housed within a fruit. Sweet fruit like apples are eaten by animals, which then disperse the undigested seeds when they defecate. Other fruits, such as coconuts, are carried by water. Some fruits, like burdock, have little hooks or barbs that can stick on to an animal’s fur or feathers. Other fruits are dispersed by the windsuch as the “winged” seeds from a maple tree that spin and “helicopter” through the air as they fall, or the light feathery seeds from a dandelion that can catch on the breeze. The longer a seed stays in the air, the farther it can be blown by the wind, helping the plant species widely scatter its offspring. In this project, you will design your own artificial seeds from craft materials and measure how far they can disperse. As with any phenotype, the seed dispersal mechanism is subject to tradeoffs. For fruits, this often comes in the form of resource allocation. Plants can either produce a few elaborate dispersal mechanisms (large wings, very sweet fruits, etc.), or it can allocate those same resources to producing more fruits, each with a less elaborate dispersal mechanism Procedure1. View the fruits on display. Record the characteristics for the different dispersal mechanisms in the table at the end of the lab.2. Next, you will be designing a dispersal mechanism for a sunflower fruit (commonly called a sunflower seed). Your group will design two different mechanisms to compare. Obtain two sunflower seeds and the supplies you will need to construct your wind dispersal mechanism.3. Use the balance to find the mass of each of your sunflower fruits.4. Construct a dispersal mechanism for each of your fruits. Your goal is to create the most effective wing using the least amount of material (remember- this is about tradeoffs).5. Once your two ‘fruits’ are complete, find the mass of each.6. Using the fan, release your seed from the designated location. Measure the distance your seed travels. Repeat three times for each seed, and determine the average. Record your values on the board.7. Next, drop your seeds from a standard height (2 m), and measure the time it takes them to reach the ground, using a stopwatch or online clock. Repeat three times, calculate the average, and record your values on the board.5. Record your groups’ data on the board.Image transcription textIII. Dispersal efficiency Your data: – plusTape cm Seed Seed *fruit* Drop time(s) Travel distance (m) ma… Show more… Show more Image transcription textClass Data: Mean distance (m) Meantime (8) Mass (1) Efficiency index Grp 1trial I 3.324 44 6 52 Gro 1 … Show more… Show moreGraphImage transcription textGRAPH SHOWING THECORRELATION BETWEEN MASS ANDEFFICIENCY INDEX 25 2… Show more… Show moreWhat do you think about the results of the above experiment between groups? Is there a relationship? Why or why not? Look at the ‘fruits’ designed by other groups. Are particular design elements associated with higher efficiency scores? Identify the outliers, either low or high, in efficiency scores. What is remarkable about these outliers? Science Biology BIOL 004A Share QuestionEmailCopy link Comments (0)
