The student assumed that water uptake was equivalent to the rate of transpiration. Give two reasons why this might not be a valid assumption? Water used in photosynthesis Water used to provide turgidity The student measured the rate of water uptake three times. Suggest how the reservoir allows repeat measurements to be made A student investigated the rate of transpiration from a leafy shoot. She used a potometer to measure the rate of water uptake by the shoot. The diagram shows the potometer used by the student. The student measured the rate of water uptake three times. Suggest how the reservoir allows repeat measurements to be made AQA Biology 7 Mass transport Exam-style questions c The student measured the rate of water uptake three times at each condition. i Suggest how the reservoir allows repeat measurements to be made. (1 mark) ii Suggest why she made repeat measurements.(1 mark) Her results are shown in the table below.Experiment Mean distance moved by air bubble in 30 minutes/mm A 120 B 175 C 30 D 35 d The cross. A student investigated the rate of transpiration from a leafy shoot. She used a potometer to measure the rate of water uptake by the shoot. The diagram shows the potometer used by the student. e) The student measured the rate of water uptake three times. i) Suggest how the reservoir allows repeat measurements to be made (1 4 A student investigated the rate of transpiration from a leafy shoot. She used a potometer to measure the rate of water uptake by the shoot. The diagram shows the potometer used by the student. 4 (a) Give one environmental factor that the student should have kept constant during this investigation
The rate of water uptake In this experiment, 0.59 grams of water were taken up by the potato cylinder. This took place over 40 minutes, so the water uptake in an hour, assuming that the rate was. Q3. Some students used the apparatus shown in the diagram to measure the rate of water uptake by a plant cutting. € The students set up the apparatus in three different conditions: •€€€€€€€€no wind at 15°C •€€€€€€€€no wind at 25°C •€€€€€€€€wind at 25° The water uptake is measured by recording the time taken for a bubble in the tube to move a set distance. Aim of the experiment To find the rate of water uptake of a plant
Some students used the apparatus shown in the diagram to measure the rate of water uptake by a plant cutting. The students set up the apparatus in three different conditions: • no wind at 15 °C • no wind at 25 °C • wind at 25 °C . For each experiment, the students recorded the movement of the air bubble along the scale The scientists measured the rate of carbon dioxide uptake by each leaf for 60 minutes in light and then for 20 minutes in the dark. The scientists' results are shown in the diagram below. (a) Suggest the purpose of each of the three leaf treatments The student cut the shoot and put it into the potometer under water. Explain why. (1 mark) Give two environmental factors that were kept constant during her investigation. (2 marks) The student measured the rate of water uptake three times at each condition. Suggest how the reservoir allows repeat measurements to be made. (1 mark
4 A leafy twig was cut from a tree and the cut end immediately placed into water. The twig was then put into a potometer to measure the uptake of water. The potometer was placed on a balance to record changes in mass. Fig. 4.1 shows the rate of water uptake and the rate of mass loss over a period of 24 hours The student did the experiment three times. (1) Another student investigated the effect of the colour of light on the rate of photosynthesis. € Mean water uptake in cm 3 per hour €€€€€Suggest how the experiment could be changed to give a reproducible way to measure the rate of the reaction A student investigated the rate of transpiration from a leafy shoot. She used a potometer to measure the rate of water uptake by the shoot. The diagram shows the potometer used by the student. € (a)€€€€ Give one environmental factor that the student should have kept constant during this investigation the rate of transpiration for species A and species B between the times of 5 and 15 minutes (show your work). Summarize the difference between the two transpiration rates. (3 points maximum) WATER LOSS VERSUS TIME FOR TWO PLANT SPECIES • Calculate transpiration rates, with units (1 point each; 2 points maximum)
(d) €€€€The students' results are shown in the table. € Number of leaves removed from the plant shoot Mean rate of water uptake / cm3 per minute 0 0.10 2 0.08 4 0.04 6 0.02 8 0.01 Explain the relationship between the number of leaves removed from the plant shoot and the mean rate of water uptake A potometer. can be used to measure the rate of transpiration that's proportional to water uptake. Transpiration cannot be measured directly as some of the water will be used in photosynthesis There are a few key methods to calculate the rate of photosynthesis. These include: 1) Measuring the uptake of CO 2. 2) Measuring the production of O 2. 3) Measuring the production of carbohydrates. 4) Measuring the increase in dry mass. As the equation for respiration is almost the reverse of the one for photosynthesis, you will need to think. 1 Transpiration in plants can be investigated using a potometer, which measures water uptake by plants. Fig. 1.1 shows a potometer that was used by a student. tap timer air bubble graduated tube reservoir leafy shoot bung beaker water Fig. 1.1 As water is lost by the leaves through transpiration, the air bubble moves along the graduated tube
Roots were rinsed three times in tap water and dried with paper. Dry weight was determined after at least 72h at 80 C. Water uptake was measured by weighing containers with nutrient solution A student used a Potometer to measure the movement of water through the shoot of a plant. As water is lost from the shoot, it is replaced by water from the capillary tube 1 . In one experiment, the air bubble moved 7.5mm in 15 minutes. The diameter of the capillary tube was 1.0mm Calculate the rate of water uptake by the shoot in this experimen Question 3. SURVEY. 180 seconds. Q. A student wanted to investigate the effect of light on the rate of ripening of tomatoes. She set up four pots of the same size with identical amounts of soil, water, and type of tomato plants. Each plant was exposed to a different intensity of light as shown in the table below
The scientist measured the uptake of oxygen by the mitochondria during the investigation. The uptake of oxygen decreased when malonate was added. The population number of both species of lizard varied at different times of the year. Suggest two reasons why. A student measured the rate of aerobic respiration of a woodlouse using the. Some students used the apparatus shown in the diagram to measure the rate of water uptake by a plant cutting. € The students set up the apparatus in three different conditions: •€€€€€€€€no wind at 15°C •€€€€€€€€no wind at 25°C •€€€€€€€€wind at 25°C For each experiment, the students. 8.During a laboratory activity, a student combined two solutions. In the laboratory report, the student wrote A yellow color appeared. The statement represents the student's recorded A) The wind speed was 200 km/hr. B) The central air pressure was 946.0 mb. C) A rain gauge records three inches of rain in less than one hour
CO2 uptake and nighttime CO2 uptake were separately deter-mined, both for the leaves and for the stems. Plants were main-tained and gas exchange was measured at or near optimal con-ditions of temperature, water status, and PAR. Because net CO2 uptake rates of C3 plants during the daytime respond rapidly t . €€€€ At which two times in the day did the rate of photosynthesis exactly match the rate of The scientists then measured the rate of oxygen uptake by the leaf discs in the dark JOURNAL OF Contaminant Hydrology ELSEVIER Journal of Contaminant Hydrology 20 (1995) 209-226 Depleted 15N carryover, leaching and uptake for three years of irrigated corn L.K. Porter USDA, ARS, Soil- Plant Nutrient Research, P.O. Box E, Ft. Collins, CO 80522, USA Received 17 November 1994; accepted 15 May 1995 after revision Abstract Deep percolation of nitrate can contribute to the.
.2. Uptake Rates. Uptake rates for each pharmaceutical were determined using the measured concentrations of the pharmaceuticals. At 24 h, EE2 showed a linear rate increase of approximately 450 ng/g as the EE2 moved up within the stalk (Fig. 5). The concentrations detected after 12 h of. 0 2 . 5 The student then compared the rate of transpiration (evaporation of water) from the two species of plant. She did this by measuring the rate of water uptake by each plant species. Suggest TWO reasons why the rate of water uptake by a plant might not be the same as the rate of transpiration. [2 marks] 1 One type is shown in the diagram. Using a respirometer to measure the rate of uptake of oxygen. The organisms to be investigated are placed in one tube, and non-living material of the same mass in the other tube. Soda lime is placed in each tube, to absorb all carbon dioxide. Cotton wool prevents contact of the soda lime with the organisms Measuring the Rate of Transpiration. To measure the rate of transpiration we use a piece of equipment called a potometer. A potometer measures how factors such as light, temperature, humidity, light intensity and wind will affect the rate of transpiration. The main type of potometer is the 'bubble' potometer shown in the figure below Assumptions of one-day vs. three-day turnover times (Akaike's information criterion [AIC] = −518.0, −518.0, respectively) or N uptake based on KCl-extractable vs. water-soluble N concentrations (AIC = −1033.3, −1033.6, respectively) had minimal effects on patterns of plant N uptake (AIC values derived from generalized additive mixed.
Amended: *RATE (referring to rate of water uptake for the whole seed) was added to this table by Specht and Rees. It was calculated just for the 'whole seed with the seed coat'. Example: The seed water content change from 0 to 2 hours was 204 g - 73 g=131/2 hours=65.5 g/kg/hour For example, the rate of change in the average water content at the bulk soil and at the rhizosphere between day 10 and day 10.05 is and , respectively. Note that for both the Static and Control scenarios, the rate of change in the average rhizosphere water content is higher than for the bulk soil (3 and 4 times higher, respectively) PO 4 3− uptake was measurable in all streams and ranged from 0-80% removal of added PO 4 3− across streams . Uptake lengths (Sw) of PO 4 3− ranged from about 57 m to 4585 m, uptake rate (U) ranged from 0-758 μg m −2 min −1, uptake velocity (Vf) ranged from 0-28.1 mm min −1 (Table 3, Figure 6)
. CO 2 + 2KOH —> K 2 CO 3 +H 2 O. The purpose of this lab was to measure the rate of cellular respiration. There are three ways to measure the rate of cellular respiration (3) (Total 11 marks) Osmosis is the movement of water through partially permeable cell membranes. A group of students investigated the effect of temperature on the rate of osmosis in potato cells. The students used five potato chips all cut to the same size. Figure 1 shows one chip. Figure 1 € This is the method used
2 uptake was 3.9 mol O 2 m22. Thus, 40% of the total O 2 uptake was due to faunal activity and respiration. The present study demonstrates the importance of realistic faunal representation during sediment incu-bations in order to obtain correct benthic mineralization rates. The oxygen uptake rate of the seaﬂoor is the most widel (3) (Total 6 marks) Q18. A students breathing was monitored before and after vigorous exercise. The student breathed in and out through a special apparatus. The graphs show the changes in the volume of air inside the apparatus. Each time the student breathed in, the line on the graph dropped. Each time the student breathed out, the line went up
The N-specific uptake rates indicated that the biofilms associated with sand and rocks were quite active for both NO 3 − and NH 4 + uptake (Fig. 5). When uptake rates were scaled per unit area of total stream (Fig. 6 ), compartments with low activity per unit N became important as well, because of their relatively high standing stocks of N. in Figure 1 to measure the rate of respiration in yeast. She: • positioned the flask in a water bath so that the yeast culture reached a constant temperature • then left the apparatus for one hour before starting her investigation. Figure 1 (a) Suggest one reason why it was important that the student left the apparatus for on where θ denotes the volumetric soil water content [L 3 L −3], t the time [T], z the vertical coordinate [L], h the soil water pressure head [L], K(h) the soil hydraulic conductivity tensor [L T −1].In the right-hand part of Eq., the two first terms describe the water flow redistribution between layers or soil locations, while the third one describes the water uptake by plant roots (S. The method was used to measure local water uptake of root segments exposed to severe drying in comparison with uptake of roots that were kept in wet soil regions (Zarebanadkouki and Carminati 2014). The results showed that root water uptake was reduced by a factor of 4-8 in those regions that were allowed to dry and then irrigated
, high wind speed may cause stomata to close a) because of the high rate of transpiration leading to water stress but also b) (when photosynthesis rate is high) gentle breeze can bring more CO 2 close to the stomata, increasing the diffusion of CO 2 into the leaf, causing guard cells to become less turgid The ventilation of three species ofNereis: N. virens, N. succinea andN. diversicolor are measured by a direct flowsensing technique. The weight dependence of ventilation suggests for all three species a direct proportionality (Fig. 3). Oxygen uptake during active ventilation is approximately 6 times higher than at rest for all three species (Fig. 4)
Caffeine Clinical data Pronunciation / k æ ˈ f iː n, ˈ k æ f iː n / Other names Guaranine Methyltheobromine 1,3,7-Trimethylxanthine Theine AHFS / Drugs.com Monograph Pregnancy category AU: A Dependence liability Physical: low-moderate Psychological: low Addiction liability Low / none  Routes of administration By mouth, insufflation, enema, rectal, intravenous Drug class Stimulant. 1 Fig. 1.1 shows a potometer that is used to measure the rate of water uptake by a leafy shoot. water cut leafy shoot rubber tubing 0 12345 mm scale 678910 tap capillary tube water meniscus Fig. 1.1 A student used the potometer to investigate the rate of water uptake of a leafy shoot. The student changed two environmental conditions This apparatus was used by a student, in a brightly lit room, to measure the rate of water loss from a leafy shoot. He measured how far the bubble moved in five minutes. He measured this three times. The results are shown in the table. (i) Use these results to calculate the mean (average) rate of water loss in cm per minute. Show your working The initial rate is the instantaneous rate of reaction as it starts (as product just begins to form). Average rate is the average of the instantaneous rates over a time period. 3. rate = +1 2 Δ[CIF3] Δt = − Δ[Cl2] Δt = −1 3 Δ[F2] Δt rate = + 1 2 Δ [ CIF 3] Δ t = − Δ [ Cl 2] Δ t = − 1 3 Δ [ F 2] Δ t. 5
Report Thread starter 12 years ago. #5. 1 cut (healthy) shoot under water (to stop air entering xylem vessels); 2 cut shoot at a slant (to increase surface area); 3 check apparatus is full of water / is air bubble free / no air locks; 4 insert shoot into apparatus under water / AW; 5 remove potometer from water and ensure , airtight. The 3 species of Nereis showed much the same pattern for the total volume of water passing the tubes per unit time (vw X D,): a decrease to a minimum at 80 to 100 mm Hg was followed by an increase at lower tensions (Fig. 3 C). On the other hand the volume of water and the magnitude of the changes was quite different. N
The scientists then measured the rate of oxygen uptake by the leaf discs in the dark. (3) (Total 9 marks) Q7. Students investigated the effect of changing the carbon dioxide concentration on the rate At which two times in the day did the rate of photosynthesis exactly match the rate Students investigated the effect of removing leaves from a plant shoot on the rate of water uptake. Each student set up a potometer with a shoot that had eight leaves. All the shoots came from the same plant. The potometer they used is shown in the diagra . Dry weight was determined after at least 72 h at 80 °C. Water uptake was measured by weighing containers with nutrient solution.Transpiration was calculated from the water uptake minus the increase in plant fresh weight
Nutrient uptake by plants in nutrient-rich water in competitive conditions was investigated with two mixed culture combinations of Limnocharis flava/Pistia stratiotes and Limnocharis flava/Ipomoea aquatica by using various initial planting densities. Further, the biomass production and other growth-related parameters were measured to understand the dominant competitive behavior 5.3 Transpiration (ESG7J) This section explains how various environmental factors can change the rate of transpiration, and also examines how the structure of the leaves has adapted to minimise this water loss. Learners will need to understand the factors that affect the transpiration rate such as temperature, light intensity, wind and humidity Page 1 of 3 Activity 7.7 Student Sheet Core Practical MEASURING THE RATE OF OXYGEN UPTAKE Purpose To investigate the uptake of oxygen in respiration. To measure the rate at which an organism respires. To develop practical skills. SAFETY Wear eye protection and disposable gloves when handling soda lime. Soda lime is corrosive In (B), samples (2, 3) were washed with water three times and centrifuged. (C) Confocal fluorescence microscopy image of sample (3) in (B). We further investigated these porous LDH-chitosan nanocomposites for the uptake and release of cosmetic liposome particles with a − 24 mV of zeta potential and size of 100-500 nm, as shown in Fig. S1 The average dissimilatory uptake potential (calculated as the share of N-NO 3-retention not accounted by autotrophic uptake under the assumption of negligible lateral and groundwater inputs) in the River Fischa was 0.69 ± 0.22 g N m −2 d −1 for Reach H and 0.27 ± 0.14 g N m −2 d −1 for Reach N, which stands for an average rate in.