The Brooklyn Latin School Name: __________________________IB Biology 2 HL Date: _____________ R: ___________

Internal Assessment #1Plant Science: Seed Germination

What is the Internal Assessment?Each Internal Assessment (IA) is a long-term student-led investigation that culminates in an extensive lab write-up which includes design, data collection and processing and conclusion. The IA are completed individually with each discipuli developing their own research question and procedure and then implementing the investigation on their own without feedback from magistri until the culmination of the project.

The two IA from senior year, combined with the Group 4 Project are worth 24% of each discipuli’s 1-7 IB score for Biology.

The broad question that we will be investigating is:

How does ______ affect the rate of germination as measured by ___________?

You will flesh out your question as you develop your project.

How will the IA be graded?TBLS and Course Grade GradingInternal Assessment Lab Practical 1 is worth 100 points to your Lab grade (30% of overall grade)

You will write a complete, typed, IB-style lab report. It will be graded with the TBLS lab rubrics. Every student is responsible for their own investigation including the development of a research question and the collection of data.

Design (D): with a design paragraph, table of variables ,and procedureData collection & processing (DCP): with raw and processed data and calculationsConclusion and evaluation (CE): with conclusion and evaluation of experiment

IB Scoring of Internal Assessment Lab Practical

Your two internal assessments combined with your Group 4 Project Personal Skills Rubric will count for 24% of your IB score. Each section of the internal assessment rubric is worth 6 points. Each internal assessment is therefore scored out of 18 points on the IB scale.

Major Deadlines Wednesday, November 26th – printed, in class copy of your proposal Sunday, Dec. 7th – full design, uploaded to Turn-it-in by 11:59 Sunday, Dec. 21st – full design + full DCP, uploaded to Turn-it-in by 11:59 Monday, Jan. 5th – bring a printed rough draft to class for peer editing Sunday, Jan. 11th – full, final product uploaded to Turn-it-in by 11:59

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What is the calendar for the IA?

November

Monday Tuesday Wednesday Thursday Friday17 Lab: Building a Seed Chamber

18 19 20 21

24 Lab: Design workshop

25 26 Proposals due 27 28

DecemberMonday Tuesday Wednesday Thursday Friday

1 Lab: Design workshop

2 3 4 5 Rough draft of lab design due Sunday at 11:59

8 Lab: Set-up experiments

9 10 11 12

15 Lab: DCP work 16 17 18 19 Rough draft of DCP section due Sunday at 11:59

22 Petri dish return

23 24 25 26

January

Monday Tuesday Wednesday Thursday Friday5 Lab: Peer editing 6 7 8 9 Final draft due at

11:59 Sunday

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Background Information

Watch the video and define:

Radicle –

Plumule -

Cotyledons –

Label the radicle, plumule, and cotyledons on the diagram below:

Read and annotate the following information about germination

A seed is essentially a baby in a suitcase carrying its lunch. "Baby" refers to the embryo, or immature plant, that will grow and develop into the seedling and ultimately the mature plant. The "suitcase" is the seed coat that surrounds the seeds and "lunch" refers to the nutritive source for the germinating seedling. The food for the germinating seedling may be stored in part of the embryo itself, such as the fleshy cotyledons of a bean seed, or it may take other forms including endosperm, which is a special starch-rich storage tissue that surrounds the embryo.

A seed is officially considered to have germinated when the young root, called the radicle, emerges from the seed coat. To germinate, a seed requires three things – water, oxygen, and a suitable temperature. Water uptake is the first stage of seed germination. During this process the dry seed, which typically has a water content of less than 10%, absorbs water and swells. This process serves to hydrate the dry components of the seed and active the metabolic machinery necessary for germination. Among the early metabolic activities occurring in the seed is the breakdown of starches stored in the seed into simple sugars that can be used for

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energy and building blocks for necessary cellular structures.

Except for the first half-hour or so of germination when little oxygen is present, seed germination and subsequent seedling growth requires oxygen. It is required, in large part, for use in the cellular structures, called mitochondria, to produce ATP (energy). A suitable temperature is necessary to optimize the metabolic reactions required for germination. The seeds of every species have an optimal temperature for germination; some species, such as the gourds and squashes prefer warm temperatures while other species such as radish can tolerate cooler temperatures for germination.

A seed that has not germinated because it is lacking one or more of the necessary requirements for germination is termed quiescent. These seeds are simply "resting", waiting for the appropriate conditions for germination. Given water, oxygen and/or a suitable temperature, a quiescent seed will germinate. However, even if given the proper conditions, a seed may not germinate. These seeds may fail to germinate because the seed is either dormant or "dead".

Dormant seeds have the potential to germinate but are prevented from doing so by some mechanism. Thus, even though all the proper growth conditions are present, they don't germinate unless they have been "primed" and there dormancy mechanism has been overcome. There are many dormancy mechanisms in seeds. For example, when some seeds, like hemp, will not germinate until they undergo a period of development (called after-ripening). Other seeds, like apple, require a brief period of cold treatment for germination. Some seeds have a hard seed coat that needs to be nicked (called scarification) for germination. This usually occurs as the result of natural freeze-thaw cycles. Still other seeds require a period of heat in order to germinate. Many of these species are winter annuals that germinate in the late summer/early fall.

Ultimately, the function of these varied dormancy mechanisms is to enable the seed time to disperse from the parent plant and to avoid germinating during unfavorable weather. Humans have attempted to breed dormancy mechanisms from our crop plants.

It’s not easy to tell if a seed is “dead.” Only if it fails to germinate when provided the proper conditions and any dormancy mechanisms are broken can we consider a seed “dead.”

Seed companies typically test the germination of seeds before sale. The results of these tests, the germination percentage, are typically provided on a seed packet. Most crop seeds lose viability rapidly after a few years. However, a few long-lived seeds are known. For example, mustard seeds show good germination after even 50 years.

For this lab we will use fast sprouting seeds, which will allow us to get data rapidly. The table adjacent presents the seed

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types that will be available, along with some basic information about the sprouts they typically form.Possible Dependent VariablesThere are many ways of assessing germination. Some relevant variables include:

The percent germination (number of seeds germinated / total started) The germination rate (change in number germinated / time) The time to emergence (the time it takes a seed’s radicle to emerge) The radicle length or plumule length The rate of radicle or plumule growth (change in length / time) Another variable of your choosing!

Trial Design GuidelinesThe number of conditions you choose will depend on what you select for your independent variable, and the data processing you plan to carry out. In general, it is better to have a greater number of independent variable conditions as they provide more sophisticated data.

If you are measuring percent germination or germination rate, one seed chamber is one trial. Because the seed chambers are bulky, you are permitted to have a lower number of trials overall. You should have a minimum of three replicate trials for each condition (Cx3)

If you are measuring shoot length, rate of shoot growth, or time to emergence, then each seed is one trial. Because the seeds are small, it should be feasible to conduct a large number of trials. Think about what is feasible.

Processing Questions

1. What is the overall research question we are investigating in this lab?

2. What is germination? What it it’s purpose? What biological processes are involved?

3. What are some different dependent variables you might measure in this lab?

4. What are some independent variables that might affect germination?

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Methods Reference Sheet

Please cite all methods as “adapted from IB Biology class packet, TBLS 2014”

Method 1: Petri Dish Seed Chamber (better for small seeds)

1. Measure and cut out a circle of paper towel to fit the diameter of the petri dish.2. Count out at least 20 seeds, and place an equal number in each dish.3. Moisten the paper with enough water so that the seeds just barely begin to float. 4. Seal the petri dish with plastic wrap or parafilm to minimize evaporation. 5. After 12-24 hours, drain any excess water from the petri dish. 6. Check each day. If the filter paper appears dry, moisten it again so that it is damp, but

not soaking. If the filter paper dries out, even for a short time, it could kill the seed.

Method 2: Ziplock Bag Seed Chamber (better for large seeds and beans)1. Soak the seeds for 12-24 hours before 2. After 24 hours of soaking, roll the seeds so they are loosely wrapped in several layers of

moist paper towel. Ensure every part of the seed is in contact with the damp paper towel.

3. Place rolled towels inside of a ziplock bag.4. Check each day. If the paper towels appear dry, moisten it again so that it is damp, but

not soaking. If the filter paper dries out, even for a short time, it could kill the seed.

Sample data table for measuring percent germinationDays since start

Total Seeds in Treatment

# Seeds Germinated During Time Interval

Percent Germination during time interval (per day)

Total Seeds Germinated Since To

Cumulative Percent Germination (since beginning)

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Brainstorming SheetsInstructions: Based on the background information, generate at least three possible lab investigations to pursue.

Brainstorming 1Research QuestionHow does ________________________ affect the germination of ________________

(IV) (species)seeds as measured by _______________________?

(DV)Trial DesignHow many IV conditions will you have? ________ What will they be, and how will you create different conditions? (describe or sketch a diagram).

How many trials will you have in each condition? _______ How will you create multiple trials?

Brainstorming 2Research QuestionHow does ________________________ affect the germination of ________________

(IV) (species)seeds as measured by _______________________?

(DV)Trial DesignHow many IV conditions will you have? ________ What will they be, and how will you create different conditions? (describe or sketch a diagram).

How many trials will you have in each condition? _______ How will you create multiple trials?

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Brainstorming 3Research QuestionHow does ________________________ affect the germination of ________________

(IV) (species)seeds as measured by _______________________?

(DV)Trial DesignHow many IV conditions will you have? ________ What will they be, and how will you create different conditions? (describe or sketch a diagram).

How many trials will you have in each condition? _______ How will you create multiple trials?

Brainstorming ReflectionYou want to narrow your focus to one research question. As you decide on your “best” question, consider the following:

1. Which project is most logistically feasible? Why? Are there any materials you are not sure about?

2. Is it plausible that your independent variable could cause a change in your dependent variable? Can you defend why it’s plausible based on biology principles, the background information in the lab handout, or your own background knowledge?

3. Which question are you most interested in? Why?

4. At the end of day 1 of our internal assessment, what is your muddiest point (the thing that is most confusing or unsure to you right now)? Write your muddiest point as a question:

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Internal Assessment #1 Project Proposal[One per person due in class, Wednesday Nov. 26th

Research Question(This should be in the format suggested in your handout)

BackgroundIn a single brief paragraph, outline the following:

What is the purpose of the experiment What seed species have you chosen to investigate? What is the official species name?

What are the normal germination requirements for this seed? You must have at least one citation showing you’ve researched your seed species.

What is your independent variable? Why is it plausible that you think this IV will affect germination? Cite the background information or do your own research.

Variables (abbreviated)Complete an abbreviated table of variables, with your IV and DV only (no constants just yet).

Type Variable Method of measurement or controlIndependent Use measurement words to

name variables: volume, mass, frequency, duration, length, height, number, concentration, distance, time, type of

PROHIBITED WORDS: “amount”

In concise sentences, explain: How many conditions of your IV are

there and what are they? Briefly, how will you create those

conditions in the lab? If your IV is measurable, how will you

measure it?

Dependent Use measurement words to name variables!

In concise sentences, explain: How will you measure your DV? If your DV requires a calculation (like

percent change), what is the formula for that calculation?

Trial DesignIn a single brief paragraph, answer the following:

How many seeds total will be utilized by your experiment? How many conditions are in your experiment? Will you have a control group? If so, describe what it is and it’s purpose. How many trials will be conducted for each condition?

MaterialsBreak this into two lists, to help you (and us) distinguish between what we have and what you will need to procure.Materials provided by the TBLS lab:

Materials provided by me:

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Last name, First nameMagister/stra NameCourse nameDue date

Research Question

DESIGN

BackgroundIn a single brief paragraph, outline the following:

What is the purpose of the experiment What seed species have you chosen to investigate? What is the official species name?

What are the normal germination requirements for this seed? You must have at least one citation showing you’ve researched your seed species.

What is your independent variable? Why is it plausible that you think this IV will affect germination? Cite the background information or do your own research.

HypothesesState your hypothesis and the null hypothesis.

VariablesType Variable Method of measurement or controlIndependent Use measurement words to

name variables: volume, mass, frequency, duration, length, height, number, concentration, distance, time, type of

PROHIBITED WORDS: “amount”

In concise sentences, explain: How many conditions of your IV are

there and what are they? Briefly, how will you create those

conditions in the lab? If your IV is measurable, how will you

measure it?

Dependent Use measurement words to name variables!

In concise sentences, explain: How will you measure your DV? If your DV requires a calculation (like

percent change), what is the formula for that calculation?

Constant Use measurement words to name variables!

In concise sentences or phrases, explain: How will you keep the variable

constant? What specific value will this variable be

kept constant at?

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Trial DesignIn a single brief paragraph, answer the following:

How many seeds total will be utilized by your experiment? How many conditions are in your experiment? Will you have a control group? If so, describe what it is and it’s purpose. How many trials will be conducted for each condition?

MaterialsCreate a bulleted list of all materials needed. Some reminders:

Glassware is named with its maximum capacity (i.e. 100-ml graduated cylinder) Scales and rulers should be listed with their uncertainty Any solutions you use should include a concentration (molarity or % by volume)

MethodWrite numbered procedure steps that summarize how you collected your data. If you modify the method given in the background paragraph, please cite the class handout (IB Bio 2 Class Handout, Hill/Martin 2014)

DiagramInsert a picture of a labeled diagram of your measurement apparatus. Diagrams can be created easily in Powerpoint or in Google Drawings.

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DATA COLLECTION AND PROCESSING

Raw DataYour raw data table – make sure it has a clear title!

Qualitative DataDescribe observations you made with your five senses during the experiment that might be relevant to your experiment but can’t be captured by a measurement alone.

CalculationsIn a sentence or two, state any calculations you performed to process your data.

Are sample calculations needed? You do not need to provide formula or examples for very common descriptive

calculations, which include: mean, range, and standard deviation. Just clearly explain how you used them (i.e. the average length of all sprouts in each condition was found)

If you have any other calculations, you must provide a formula and show your work for one example for each calculation.

Processed DataYour processed data table, if your processed data is not grouped with the raw data. Make sure there is a clear title here too!

Your graph goes here too.

If you have more than one graph, you should have a few sentences before each graph that explain why you chose to include it. Your work should read like a narrative.

Statistical Analysis (only if doing a stats test)In a few sentences, explain why you thought calculating a statistical test would be useful for this data and why the statistical test you chose is appropriate for your data. Then, you must:

State whether you calculated the test in Excel or by hand State the relevant values for your test (if you calculated by hand there will be more) Interpret the results of your test what they tell you about your hypotheses

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CONCLUSION AND EVALUATION

ConclusionYou should structure this like TWO argumentative paragraphs. The first paragraph should address your conclusion, and the second should address your confidence in that conclusion.

Your conclusion is your final answer to the research question. You must justify that answer with data from your experiment. Data could include:

Trends or patterns in the graph Differences or lack of differences between groups (control vs. experimental, or

experimental vs. experimental) Patterns or changes in the variance (as shown by the error bars) Results of statistical test Qualitative data that illuminates what you believe happened in your experiment

Confidence refers to how much certainty you have in your conclusion. When evaluating the level of confidence, you might consider the following questions. If you answer yes to any of these you should not be fully confident:

Are the error bars large and overlapping? Are the uncertainties in your measurements large compared to the difference you

measured? Was your sample size very small, or in some way biased or not representative? If you found a line of best fit – does it fit the data well or are there significant outliers?

Do you have enough points to support the line, or are you doing a lot of extrapolating (drawing a line based on 2 or 3 data points)?

Consider the limitations you identified – in your estimation, are their fairly significant?

CONCLUSION PARAGRAPH STRUCTUREConclusion / topic sentence: Your final conclusion about the research question based on the data. You might comment on whether the results support your original hypothesis, null hypothesis, or an alternate hypothesis you hadn’t originally considered.

Evidence 1 : Be specific: “There was an increase of 15 mm on average” is better than “the height increased.”

Analysis 1: Explain how this data supports or challenges your conclusion Evidence 2: Analysis 2: Evidence 3: Analysis 3:

CONFIDENCE PARAGRAPH STRUCTURETopic sentence: Based on _______________, one can be (fully / moderately / minimally) confident in the conclusion outlined above.

Supporting evidence 1 (choose from the guiding questions above and explain how this justifies your confidence statement)

Supporting evidence 2 (choose from the guiding questions above and explain how this justifies your confidence statement)

Evaluation

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You will write at least THREE paragraphs. Each paragraph should consider one limitation of the investigation at a time and address the following questions:

1. What was the limitation? Was it a design flaw, execution error, or limitation of the apparatus and equipment you used?

2. How did the limitation affect the quality of your data? Did it skew your results – if so, how? Did it widen the variability or range of your data?

3. In the future, how could this limitation be avoided? This should read like a procedure step - include equipment you would need and numerical values you would revise.

Declaration“I affirm that this work represents my own ideas and thinking, except for the sources I have acknowledged within. I affirm that all data are authentic, and I have neither changed nor invented data in the process of reporting and analyzing my findings.”

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