• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Investigating the Effects of Salt on Seed Germination

Extracts from this document...

Introduction

Seed Germination Investigation PROBLEM/RESEARCH QUESTION In this investigation, we are researching and investigating whether the concentration/percentage of NaCl (salt) in water affects the germination rate of seeds and if so, which concentration germinates the most seeds. We will formulate our research by conducting an experiment in which we will observe the germination of seeds in various concentrations of salt water and evaluate the results gathered. In particular, we will measure the percentage of seeds germinated in one week and formulate our conclusions from there. HYPOTHESIS I hypothesise that the highest percentage of seeds will germinate in the petri dish that contains the lowest percentage of NaCl in water- 0.5% salt salinity and the percentage will decrease as the percentage of salt in the solution increases. I predict this because I know from prior knowledge that seeds need to be able to absorb H2O to germinate and salt prevents this. So if we increase the amount of salt and therefore, decrease the amount of H2O in the solution, germination of seeds will occur less than those in lower percentages of salt, thus allowing for the 0.5% solution to germinate the most seeds as it contains the least amount of salt out of our five different samples. VARIABLES The independent variable (the variable being changed): The independent variable is going to be the concentration/percentage of salt in water (%). This variable will be changed and a different percentage of NaCl will be used in every petri dish. We will measure and change the concentration of NaCl with water for each petri dish by measuring and pouring 5mL of solution from a particular solution bottle and into a petri dish, using a different solution bottle-which contain different concentration of salt-for each dish. ...read more.

Middle

2. Place the five petri dishes next to each other with their lids and make sure that they are the same size and make. 3. Label with the marker a different NaCl percentage on each lid (0.5%, 1%, 1.5%, 2%, 2.5%). Ensure that lids do not get mixed up with each other. 4. Divide the 30 cotton wool balls into groups of six so that there are five groups. 5. Place each group of cotton wool balls inside a different petri dish and space them out evenly in the dish, ensuring that there is very little gap between them. Macintosh HD:Users:160161:Desktop:Screen Shot 2013-08-26 at 7.53.24 PM.png 6. Divide the 50 cress seeds into groups of ten and place each group into a different petri dish. Place them gently on the surface of the cotton wool balls, spreading them evenly around the edge with a 1cm gap between them. 7. Measure out 5mL of the 0.5% NaCl solution in a measuring tube and carefully drop the solution on the seeds in the respective petri dish with the label: 0.5%. Ensure that all of the solution is dropped on the seeds and not on the side. 8. Repeat the step 7 with the 1% solution; ensuring the measuring tube is washed before. Remember to pour the solution on the seeds in the petri dish with the label 1%. 9. Repeat step 7 again with the 1.5%, 2% and 2.5% NaCl solutions, remembering to wash the measuring tube each time and pouring the solutions to their respective labeled petri dishes. ...read more.

Conclusion

is used. Our method was fairly clear, concise and allowed us collect our data in a fairly orderly way, doing so for most tests. It allowed us to complete the experiment with accuracy excluding the human errors present. Although our method is quite accurate, there are many improvements that could be made to it. These include: * Reducing the chance of human interference affecting the results (different amounts of solution poured on each seed.) Using a fixed amount for each seed (e.g. 1mL)-instead of just trying to divide 5mL across ten seeds- could solve this problem. * Using a wider range of concentrations so that the trend can become more evident and more precise conclusions can be drawn on the increase/decrease of seed germination rate. * We could test each concentration of NaCl three or four times and develop an average, excluding results that stand out so that our data becomes more reliable. * We could leave the seeds for a longer period of time (e.g. one month) in natural conditions such as a pot or flower bed and water them daily with the various concentrations of NaCl and see which seed has grown the most after the one-month. * We could extend this experiment by investigating whether using a different type of seed effects the germination rate and if so, which species of seeds germinates the quickest and most consistently. * We could also investigate how long it takes for every seed to germinate for each concentration and whether using soil instead of cotton wool affects the results. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Marked by a teacher

    Biology: Lab report Germination

    4 star(s)

    We chose to make two control experiments. We decided this because we could each monitor one of them and it would also offer additional reliability. 1. Cover the bottom of the Petri dish with a layer of cotton wool. 2.

  2. Seed Germination Experiment. How would different levels of temperature of water affect the rate ...

    According to the results that were obtained, most of the seeds were germinated between 15�C - 20�C; which shows that this lab was done correctly. Also, the dish that held the seeds that germinated closest to its full potential was dish #5, as the diameter of the radicle was 3.89 � 0.08 mm.

  1. The Effects of Salinity on Wheat Germination

    At least one-third of the world's population depends on wheat as its main staple. The principal food use of wheat is as bread, either leavened or unleavened (Access Online Encyclopaedia, accessed Monday 23rd of February). Salinity is of particular reference when dealing with harsh arid and semi-desertal climate of Australia (Australian Bureau of Meteorology website, accessed Monday 23rd of February)

  2. Ecology Open Investigation Does the geographic location affect the biotic and abiotic ...

    However for these two features, the Null Hypothesis was rejected in favour of the hypothesis which was that the geographic location does affect the abiotic factors BL and 18MS. Calculations of the health of the experiment sites were also determined by carrying out a biotic survey in Table 2.0.

  1. Bio lab - Oxygen Consumption in germinating and non-germinating seeds

    The food colouring was dropped into the water by using the medicine dropper. 7. After three minutes, the initial position of the water in the pipette was recorded to the nearest 0.01 ml. Record was checked every 2 minutes for 10 minutes in total.

  2. Biology- Extended essay. For this research, I investigated the effects of DDT and ...

    This particular species of fish will help us in calculating its opercular movement, thus determining the affects DDT and the Azo-Dye on the fish. ABOUT DDT:- DDT is probably the most infamous synthetic pesticide obtainable today. DDT is a constant organic pollutant that is exceedingly hydrophobic and greatly absorbed by soils.

  1. What is the effect of increasing pH concentration (pH 3, 4, 5, 6 and ...

    Length of stem ( + or ? 1cm) Number of leaves(+ or -1) Color of leaves Day 1 0.4 0.4 0.3 0.3 0.4 0.3 0.3 0.3 0.2 0.2 - - - Day 3 0.8 1.3 1.0 1.5 1.2 1.0 1.2 1.0 1.1 1.2 1.6 1.5 1.7 1.6 2.0 1.8 1.7

  2. How does the salinity of water affect the germination of mung been seeds as ...

    seeds has on the seeds ability to begin germination as shown by the mean number of seeds with a cracked testa four days after solution was added to the seeds? Salinity of Water (mol L-1) Mean number of mung bean seeds with a cracked testa four days after being exposed

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work