Plant Transpiration Activity, Lab, and Questions

The Online Lab Setup 

In class we have been learning about plant evolution, photosynthesis, and now transpiration. For homework, we did an online lab that tested the different amounts of transpirations in 9 different plants. The transpiration levels were tested using a heater, fan, and light as possible factors of influence. All of these environmental factors effected each of the plants by increasing their rate of transpiration.


The picture below is what was used in the lab to help determine the mL of water. 

The results of the 9 different plants are posted down below in the table.

Table of Data for Plant Transpiration Lab 

After completing the lab, the website offers more information regarding plant transpiration:

"What factors affect the transpiration rate in plants?

In vascular plants, water is absorbed through the roots and carried upward through the stem to the leaves. The force behind this upward movement is called capillary action, a force of attraction between molecules that causes liquids to move up narrow tubes, such as those inside a plant's stem. 

Some of the water absorbed by a plant's roots is used for photosynthesis, but much is lost to the environment through a process called transpiration. During photosynthesis, tiny pores on the surface of the leaves, called stomata, open to permit the intake of carbon dioxide and the release of oxygen. Because the stomata must remain open for the exchange of gases, large amounts of water are lost to the environment through evaporation. 

Water that evaporates from the leaves is continually replaced with water that is absorbed through the roots. Therefore a plant's rate of transpiration can be measured by observing the amount of water taken up through a plant's roots over a period of time. The transpiration rate can be approximated by measuring the amount of water taken up in a short time through the plant's stem. 

In a laboratory, a plant's transpiration rate can be measured using a potometer. A potometer can be assembled from standard laboratory materials including: a ring stand, clamps, a 10mL pipette, a 100mL burette, a T-tube, glass tubing, and rubber tubing. 

To measure transpiration rate, a plant sprig is mounted on the potometer and the burette and pipette are filled with water. Over time the plant will transpire and absorb water through its stem. The potometer is constructed in such a way that the plant's water source is the pipette, therefore the amount of water transpired over time can be determined by reading the water level in the pipette after time has passed. The water supply in the pipette can be replenished from the water supply in the burette by releasing the pinch clamp." (Information Source)

Lastly, we were asked to complete the journal questions that followed up the lab.

Journal Questions:

1.) Describe the process of transpiration in vascular plants.

Transpiration is the release of water from a plant, as the water evaporates into the atmosphere from the leaves and stems of plants. In transpiration, water travels from the soil into the roots of plants, and up to the underside of plant leaves, where it is released into the air. This evaporation of water from plants into the atmosphere happens due to the small pores in the leaves called stomates. Stomates are small openings underside leaves that are connected to tissues of a vascular plant. 

2.) Describe any experimental controls used in the investigation.

The controls for the plants were by testing the normal amounts of transpiration in the plant without the influence of any environmental factors. 

3.) What were environmental factors that you tested increased the rate of transpiration? Was the rate of transpiration increased for all plants tested?

All of the factors that were tested (heat, wind, light) influenced the rate of transpiration by increasing it. In the data, all of the plants showed the same increase with these factors.

4.) Did any of the environmental factors (heat, light, or wind) increase the transpiration rate more than the others? Why?


The heat increased the rate of transpiration in the plants the most. This is because the heat acted as a type of  "catalyst" to speed of the rate in which the plant transpires. 

5.) Which species of plants that you tested had the highest transpiration rates? Why do you think different species of plants transpire at different rates?

Based on the data collected, the rubber plant had the highest rate of transpiration. Different amounts of water found in soil can influence this, as well as the plant's own metabolic rate. 

6.) Suppose you coated the leaves of a plant with petroleum jelly. How would the plant's rate of transpiration be affected?

The jelly would impact the plant's rate of transpiration by slowing it down significantly. This would occur because the jelly would block the plant's stomata on its underside, and now allow the water in the plant to evaporate. 

7.) Of what value to a plant is the ability to lose water through transpiration?

Because water has cohesion between its molecules, the water is "pulled up" through the xylem. When the water evaporates, this creates the transpiration flow through the xylem and carries any dissolved nutrients with the water itself. For plants, having the ability to draw water and nutrients upwards to branching leaves allows plants to spread its leaves to receive more necessary sunlight.

Predator vs. Prey Simulation

In class, we began reviewing how the population numbers of predators or prey can effect the equilibrium and population of the other. We used a simulation with paper to display the effects of the rise and fall of prey and predator species. In our simulation, we explored the numbers of hares to wolves in the arctic tundra. The color of the rabbits and the sizes of the wolves were also a factor that we analyzed in our data. After 12 trials, the data we collected is graphed below.

X Axis: Round
Y Axis: Population Numbers
Series 1: White Hare
Series 2: Light Colored Hare
Series 3: Dark Colored Hare
Series 4: Small Wolf
Series 5: Large Wolf

Predator vs. Prey Graph

In analyzing the data, many of the things we noticed corresponded with topics we learned earlier this year. For example, the natural selection between each of the species showed favoritism towards specific hares and wolves. The white colored hares showed a much larger survival and reproduction rate, opposed to the darkest colored hare because of the environment in which they're in. A light colored hare is much more likely to survive in the tundra because of its color and ability to camouflage. The larger wolf was also able to catch more rabbits, survive, and then reproduce. The smaller wolf had a decline in population because it wasn't able to sustain itself with its small size. 

A Natural Disaster

I returned on a trip to the deserts and xeric shrub-lands, only to notice some changes to the environment had occurred.

 There was a severe fungal infection that was spreading throughout the different species of cacti.The consequences of this seemed to be pretty significant. I enlisted the help of a botanist to better explain what was going on and the long term-term effects on the desert biome and the dwellers in it.




It is generally difficult for a cactus to contract a fungal infection, because typically there is some type of insect infestation that occurs, and can sometimes leave behind a fungal type surface. In the rare case the cacti are infected, they proceed to turn brown and die as the fungus eats away.

 

 According to the botanist helping me, 

"Fungal attacks are extremely difficult to stop. The best option is to find any uninfected stems and re-start a new plant from them and throw the rest of the plant away. Fungicides are available that could slow down the fungus attack, but the fungus rarely is eliminated in this way."

 So it looked like this fungus was here to stay. This new infection was impacting the organisms in the biome, and the biome itself. With the cacti becoming infected, the species and biodiversity in the desert was depleting. Also, with less cacti, it was difficult for the species to reproduce and makes it difficult for the species to maintain their population equilibrium.

This is catastrophic to a biome. If a producer becomes affected in any way, there is severe consequences. This is because producers are on the bottom of the food chain and impact the primary, secondary, etc. consumers, as well as decomposers. It basically effects the entire food chain above it and has the ability to wipe out numerous species. For example, a a rabbit, which is a primary consumer, will have much less food options because of the producer being wiped out. The rabbit might then emigrate to a different region in order to find food, or in the worst case, die from starvation. This would then effect a secondary consumer, such as a wolf that eats rabbits, because now his food source has gone down significantly. When the bottom of the web is wiped out, it will eventually wipe out almost everything else. The animals that help enrich the environment will now be gone, and the environment will suffer as well. 

The only organisms that might be able to survive the disaster are the decomposers that feed off the carcases of deceased consumers and producers. They would have an influx in food supply and might be able to live and reproduce. 

Overall, the biome would suffer greatly, as it would lose a very large majority of its species and the plants that make up the environment would become sparse, and then almost entirely depleted.

A Trip to the Desert: Biome Activity

I recently embarked on an adventure, curious to learn more about biomes on earth. Because I can't stand rain, and I really hate the cold, the rainforest and tundras were immediately ruled out. Eventually I decided that the desert and xeric shrub-land regions were my only option. With my mind set on a destination, my journey began. 

Knowing only minimal information about the desert (basically only knew that it's hot) I began researching about this environment to better understand what I was getting myself into. 






With more research now being acquired, picking a definite region to travel to experience the biome was difficult. I never realized how many options there were to visit a xeric shrub-land in the world! It is the largest terrestrial biome, responsible for covering about 19% of the earth's land surface area.

Photo Courtesy of WWF

Worldwide, these desert shrub-lands can vary vastly in the amount of rainfall in which they receive. The evaporation in the regions exceeds the rainfall by a landslide, allowing for only about 10 inches of rainfall annually. The temperatures in these regions also vary greatly. Some regions, such as the Gobi in Asia, become quite cold in the winter and temperatures drop drastically, whereas other deserts, such as the Sahara, stay sweltering hot year-round. 



If you compare the temperature vs. precipitation graphs of the two deserts mentioned above, it is clear to see their climate differences! The Saharan desert's temperatures do not drop as much, or have as large of a temperature high and low as in the Gobi desert.

The Temperature and Precipitation Graph of the Gobi Desert in Asia

The Temperature and Precipitation Graph of the Saharan Desert

All those hot temperatures probably have to do with the great amounts of bright sunlight that the desert regions receive. When comparing the map of xeric shrub-lands in the world to the map of solar radiation, the most intense regions match up with some type of a desert, Saharan type of area. You can see many of the desert regions can receive over 3000 hours of bright sunshine, per year! I might want to bring some sunglasses...

With all these extremely hot temperatures, and almost non-existent rainfall, I wondered if life could really exist in these regions. Is it possible to have an extensive ecosystem full of various species and plant-life when it's just so hot?

Photo Courtesy of Green Tech

I first did a little research about the soil and earth that makes up these deserts. I learned that because biomass productivity is low, the litter layer is almost nonexistent and organic content of surface soil layers is very low. Not only that, the evaporation that the desert experiences causes a strong concentration of salts on the top layers of the surface. 

So far, I wasn't convinced there could be life yet in these vast, hot, sand-lands. 

Photo Courtesy of Citadel

Since the ecosystem and climate is very unique and specific, only certain plants can survive. The main producer in the desert ecosystem is the cactus! The cactus acts a primary source and the beginning of the food chain for the consumers, and then later on, the decomposers. Let me tell you, the desert is FULL of plant and animal life. Here are just some of the common cacti you might find in a desert region.


It's a dog-eat-dog world out there, and the desert isn't excluded from this at all. These cacti, or producers, act as a feeding source for the consumers. The most common desert consumers include insects, rats, lizards, quails, deers and other grazers. While secondary desert consumers include small and large predators such as snakes, hawks, and coyotes. These consumers feed off of plants such as producers, and can sometimes feed off of other consumers as well. The decomposers come later on in the cycle and usually feed off of dead animals and help break them down, or, decompose them. Decomposers may include, bacteria, worms, or fungi, that eat things usually none of the other animals in the ecosystem might.  

However, it's not as dark and grim as it seems! A lot of these species share symbiotic relationships. A symbiotic relationship is one in which two organisms equally benefit from each other through a series of events or actions. An example might be a bee pollenating the flowers of a cactus, allowing not only the bee to benefit and do what it needs to, but helping the cactus as well the grow and reproduce.

Photo Courtesy of Green Acres Ranch

This bustling eco-system is rich with different plant and animal species. Unfortunately, disturbances to their environment can cause difficulties or even eradication to the different dwellers of the desert. Humans are typically the most responsible in the destruction or interference of this ecosystem.
One of the most prevalent issues concerning the desert today is the impact of global warming (for more information check out the link). The climate changes cause all sorts of disturbances in the habitat, such as more incidences of droughts which dry up water holes in the already barren desert. This can and does impact species severely. Also, the higher temperatures allow for wildfires more easily which can alter and destroy desert landscapes and shelters needed by the dwellers. Other dangers include irrigation created by farmers, which can eventually lead to higher salt levels in the soil, which will then not be able to support as much, or any, plant life. For a more extensive outlook on the dangers, refer to this great article by National Geographic.

With all these harsh climates, and human influence, it must be difficult for species to survive. However, most of these organisms have undergone specific mutations and adaptations which allow them to be better suited for the climate and environment. They have overcome barriers which the natural habitat has presented to them by finding unique ways to survive:

Courtesy of Living Desert

With all this information down and my newly acquired knowledge, I think I'm finally ready to face the desert and xeric shrub-lands! I know it won't be easy, but I know what I'm coming up against. I'll be sure to pack a lot of sunscreen, water, and light clothing for this trip. Stay tuned for my biome journey!

If you're interested in learning some more, or just summing my blog post briefly, here are some very informative videos courtesy of National Geographic.

Sources:

http://www.livingdesert.org/desert_animals.html
http://resources.woodlands-junior.kent.sch.uk/homework/adaptations/desert.htm
https://www.youtube.com/
http://www.blueplanetbiomes.org/desert_animal_page.htm
http://www.desertusa.com/desert-food-chain/food-chain-2.html
http://citadel.sjfc.edu/students/naa07113/e-port/decomposers.html
http://en.wikipedia.org/wiki/Deserts_and_xeric_shrublands
http://wwf.panda.org/about_our_earth/ecoregions/about/habitat_types/selecting_terrestrial_ecoregions/habitat13.cfm
http://environment.nationalgeographic.com/environment/habitats/desert-map/
http://www.eoearth.org/view/article/177257/

Investigating Behavior

Lab Abstract: 

In this lab Rollie Pollies, also known as Pillbugs or Armadillidiidae, were the subjects used in the lab test for senses. By analyzing and interpreting the data, interactions, and behavior of the small crustaceans, my group was able to deduce possible characteristics of the bugs regarding the vision, smell, and other senses.

Introduction: 

Behavior is defined as the aggregate of responses to internal and external stimuli. In our lab, we observed the behavior of the rollie pollies as we presented external stimuli in the behavior chambers such as water, light, food, etc. We tested its affinity and behavior towards certain environments, which then helped us hypothesize certain senses. For example, using light and dark, and moist or dry, helped us better understand the bugs and how they interact. 

Ethology, the study of behavior, first began in prehistoric times for practical uses such as hunting. Today, the field of ethology has expanded greatly and with much deeper understanding. Animals can exhibit two types of behavior: inherited and learned. Inherited behaviors are behaviors animals are born knowing. They are very "instinctual" for the animal. This can include a female mammal nursing her young at the time of birth. Learned behaviors, are ones acquired in life that can be taught by a parent or pack. Hunting is the primary example of this. 

For inherited behaviors, there are two different categories: reflex and instinct. Reflex behaviors act as an automatic response that don't involve messages from the brain. However, instinctual behaviors are complex patterns from inherited behaviors. A reflex behavior could be an animal pulling away when touching a sharp object, whereas an instinctual behavior could be a small animal being able to stand up after birth. 

There are 3 types of behaviors which may be either inherited or learned: orientation behaviors, agonistic behavior, and mating behavior. 

Orientation behaviors are what bring the animal to its most favorable, ideal environment. A taxis, an automatic, oriented movement, is then what can either drive the animal towards or from certain a stimulus. In our lab this included the water, sugar water, and light. Taxis are often observed in these types of stimuli. Opposite to taxis, is kinesis, which is a simple, random change in activity or turning rate in response to stimuli.

Agnostic behavior is how animals respond to each other in either submissive or aggressive manners. An example of this may be a dog showing its teeth before wanting to attack another animal. 

Mating behaviors are behaviors animals present that include finding, courting, and mating with members of the same species. 

There are two types of questions to ask about animals' behavior. Proximate causation is an explanation of animal's behavior based of the trigger stimulus and internal mechanisms. Ultimate causation is the explanation of animal's behavior based of evolution. This requires that behavioral traits, are genetically heritable, and then can be explained why the behavior was favored and passed down through natural selection. 

Example Behavior: A songbird's song
Proximate Question: When does the bird know to sing?
Ultimate Question: Why does the bird use song? 

Fixed Action Patterns, or FAP, is defined as a sequence of unlearned behaviors that is essentially unchangeable, and once it is initiated , it is usually carried to completion. For example, during mating season, male red-bellied sticklebacks show aggressive behavior when triggered by anything red, the stimulus. 

Imprinting, is a type of behavior that has both aspects of learning and innate components. Typically, imprinting is irreversible. It distinguishes itself from the other types of learning because of its limited phase in animal's development in which the certain behavior can be learned. A proximate cause for a young goose imprinting on its mother is because of the goose seeing the mother moving away from it and calling out for them. An ultimate cause might be that the young geese that imprint and follow their mothers have an increased survival rate due to them receiving more care and learning vital skills, opposed to those who don't.

Lastly, there are two types of associative learning: classical conditioning and operant conditioning. Classical conditioning occurs when an arbitrary stimulus is associated with a reward or punishment. This involves the pairing of stimuli and the association that results between the two. A behavior that would normally be the result of one stimulus becomes the result of the other also due to the association created. An example would be Pavlov's dogs salivating at the sound of the bell they'd come to associate with being fed. Operant conditioning is a type of associative learning in which animals learn to associate one of its own behaviors with a reward or punishment. It is a type of trial-and-error learning. Operant conditioning requires that the subject perform some action, and that the action is either rewarded or punished to either encourage or dicourage the behavior.

Question:

Are rollie pollies' behaviors, shown in response to stimuli introduced to the behavior chambers, kinesis or taxis? 

Hypothesis:

Series 1:

If the rollie pollies are placed in a behavior chamber with a dry side and a damp side, then the rollie pollies will gradually move over to the moist side because of their behavior observed in nature.

Series 2:

If the bugs are placed in a behavior chamber containing sugar water on one side and regular water on the other, then the bugs will stay on the natural water because they do not tend to favor sugary-water in nature. 

Series 3:

If rollie pollies are placed in a behavior chamber with half light and half dark, then they will favor the dark side because of their favorability of the darkness.

Overall Hypothesis:

If the bugs collect on the same side, then the response must be taxis, since the behavior they displayed is consistent. 

Materials: 

- Vessel for Collection
- 10 Rollie Pollies
- Paint Brushes
- Behavior Chambers
- Filter Papers
- Pipet
- Sugar Water
- Pure Water
- Lamp 

Procedure: 

1. Collect 10 rollie pollies outside, with the use of the collection chamber
2. Once the 10 are captured, bring them inside to begin observation
3. Place the bugs in a behavior chamber containing nothing inside (control)
4. Observe them for 5 minutes, noticing anything interesting in their behavior
5. Create 3 different experiments testing the senses of the bugs 
6. Use the chambers to test the hypothesis 
7. Test the variable for 7 minutes and record the data observed

Data Tables, Observations, and Graphs: 

Series 1: Dry Chamber vs. Moist Chamber 

(Affinity towards dampness) 

Time (in minutes)	# of Rollie Pollies in the Dry Chamber	# of Rollie Pollies in the Moist Chamber
0	12	0
0.5	8	4
1.0	7	5
1.5	7	5
2.0	6	6
2.5	5	7
3.0	6	6
3.5	6	6
4.0	5	7
4.5	5	7
5.0	5	7
5.5	5	7
6.0	5	7
6.5	3	9
7.0	3	9

Series 2: Sugar Water vs. Pure Water

(Affinity towards taste, sweetness) 

Time (in minutes)	# of Rollie Pollies in Pure Water Chamber	# of Rollie Pollies in Sugar Water Chamber
0	12	0
0.5	10	2
1.0	8	4
1.5	10	2
2.0	10	2
2.5	10	2
3.0	8	4
3.5	8	4
4.0	9	3
4.5	10	2
5.0	9	3
5.5	9	3
6.0	10	2

Series 3: Lightness vs. Darkness

(Affinity towards light, vision) 

Time (in minutes)	# of Rollie Pollies in Light Chamber	# of Rollie Pollies in Dark Chamber
0	0	12
0.5	2	10
1.0	1	11
1.5	1	11
2.0	2	10
2.5	2	10
3.0	3	9
3.5	3	9
4.0	2	10
4.5	1	11
5.0	1	11
5.5	1	11
6.0	1	11