Grade 11 Biology: Ring Barking Experiment
56 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary purpose of ring barking in the experiment?

  • To reduce the diameter of the tree stem
  • To increase the water supply to the tree
  • To test the effect of environmental conditions on growth
  • To demonstrate the role of phloem in organic substance transport (correct)

    • What is the expected outcome for the stem above the ring of bark after one month?

  • It swells and its diameter increases (correct)
  • It remains unchanged in diameter
  • It becomes discolored and withers
  • Its diameter decreases

    • Which variable is manipulated in the experiment?

  • Condition of the stem above the ring
  • The amount of Vaseline applied
  • Presence of a ring in the stem (correct)
  • Environmental conditions surrounding the tree

    • What is a constant variable in the ring barking experiment?

    <p>The environmental conditions affecting tree growth</p> Signup and view all the answers

    What tool is used to measure the diameters of the tree stem in the experiment?

    <p>Measuring tape</p> Signup and view all the answers

    What color will a food sample turn if starch is present during the iodine test?

    <p>Dark blue or blue-black</p> Signup and view all the answers

    Which of the following is NOT a material required for the food test experiments?

    <p>Vegetable oil</p> Signup and view all the answers

    How much water should be added to each test tube during the starch test?

    <p>2 mL</p> Signup and view all the answers

    Which step comes first when conducting the iodine test for starch?

    <p>Add food sample to a test tube</p> Signup and view all the answers

    In the procedures of the food test, after adding iodine solution, what should the student do next?

    <p>Indicate the change in color in the results table</p> Signup and view all the answers

    What is the primary purpose of adding ethanol in the Emulsion Test for lipids?

    <p>To create a cloudy emulsion if lipids are present</p> Signup and view all the answers

    What should you do after adding distilled water and ethanol to the food sample?

    <p>Shake the solution gently and observe the results</p> Signup and view all the answers

    Which of the following precautions is essential when performing the Emulsion Test?

    <p>Keep the ethanol away from open flames</p> Signup and view all the answers

    What would indicate that lipids are present in the food sample during the Emulsion Test?

    <p>A cloudy white emulsion forms</p> Signup and view all the answers

    In the results table, what should be noted for the iodine solution when testing for lipids?

    <p>No change indicates the absence of starch</p> Signup and view all the answers

    What color change indicates the presence of glucose or sugar during the Benedict's test?

    <p>From cloudy green to yellow to red</p> Signup and view all the answers

    At what temperature should the water bath be set for the Benedict's test?

    <p>80°C</p> Signup and view all the answers

    What is the purpose of adding water to the test tubes before adding Benedict's solution?

    <p>To ensure consistent heating</p> Signup and view all the answers

    Which of the following is not a step in performing the Benedict's test?

    <p>Mix the solution and hold it directly over the flame</p> Signup and view all the answers

    What is indicated by a red precipitate of copper (II) oxide in the Benedict's test?

    <p>Presence of sugar</p> Signup and view all the answers

    Which types of cells are included in the structure of xylem?

    <p>Xylem vessels and tracheids</p> Signup and view all the answers

    What is the primary function of parenchyma cells in xylem?

    <p>Store food substances</p> Signup and view all the answers

    What is a key structural feature of xylem vessels?

    <p>Perforated end walls and a hollow tube structure</p> Signup and view all the answers

    Which of the following correctly describes tracheids?

    <p>Water-conducting cells with pits</p> Signup and view all the answers

    How do fibres contribute to xylem structure?

    <p>They provide structural support.</p> Signup and view all the answers

    What is the first step in conducting the Biuret test for protein?

    <p>Place the food sample into a test tube.</p> Signup and view all the answers

    What color change indicates the presence of protein during the Biuret test?

    <p>Purple</p> Signup and view all the answers

    Which two solutions are added to the food sample in the Biuret test?

    <p>Biuret A and Biuret B</p> Signup and view all the answers

    After adding Biuret A and Biuret B, what should the tester do next?

    <p>Shake the solution gently.</p> Signup and view all the answers

    What type of information is recorded in the table of results during the Biuret test?

    <p>Any color changes observed.</p> Signup and view all the answers

    What is a characteristic feature of sieve tube cells?

    <p>They lack a nucleus.</p> Signup and view all the answers

    What role do companion cells play in phloem tissue?

    <p>They control the activity of sieve tube cells.</p> Signup and view all the answers

    Which structure in the sieve tube cells allows for the flow of sap?

    <p>Sieve plates</p> Signup and view all the answers

    What is the primary function of the cytoplasm in sieve tube cells?

    <p>To contain the sieve plates and aid in transport.</p> Signup and view all the answers

    How do sieve tubes appear in a longitudinal section of phloem?

    <p>They show a regular pattern of sieve plates.</p> Signup and view all the answers

    What is the primary effect of removing the phloem tissue during the bark ringing process?

    <p>Disruption of organic substance flow from leaves to roots</p> Signup and view all the answers

    Why is Vaseline applied to the exposed tissues during the bark ringing procedure?

    <p>To prevent air from entering the xylem</p> Signup and view all the answers

    What occurs below the ring on the trunk of a tree after phloem is removed?

    <p>Accumulation of organic substances leading to wilting</p> Signup and view all the answers

    What is the consequence of a ringed main trunk on the entire tree over time?

    <p>The tree may die due to lack of nutrients</p> Signup and view all the answers

    Which statement best describes the immediate effect on the tissue above the ring after bark ringing is performed?

    <p>It swells due to the accumulation of organic substances</p> Signup and view all the answers

    What is the primary function of lignin in xylem vessels and tracheids?

    <p>To strengthen cell walls and prevent collapse</p> Signup and view all the answers

    How do xylem vessels and tracheids contribute to water transport in plants?

    <p>They have small openings called pits</p> Signup and view all the answers

    What is the role of companion cells in phloem tissue?

    <p>Supply nutrients and support sieve tube cells</p> Signup and view all the answers

    Why do sieve tube cells lack a nucleus when mature?

    <p>To facilitate efficient transport</p> Signup and view all the answers

    What distinguishes tracheids from xylem vessels?

    <p>Tracheids are longer and have a smaller diameter</p> Signup and view all the answers

    Which type of substance is primarily transported by phloem?

    <p>Organic substances such as sucrose</p> Signup and view all the answers

    What happens to the cytoplasm of xylem cells during their maturation?

    <p>It disintegrates, leaving a cavity</p> Signup and view all the answers

    What is the function of phloem parenchyma cells?

    <p>Store food substances</p> Signup and view all the answers

    What is the term used to describe the transport of dissolved organic substances in the phloem?

    <p>Translocation</p> Signup and view all the answers

    Which of the following is the main component of phloem sap?

    <p>Sucrose</p> Signup and view all the answers

    What percentage of water absorbed by plants is used for photosynthesis?

    <p>1%</p> Signup and view all the answers

    Which factor contributes least to the rate of transpiration?

    <p>Soil temperature</p> Signup and view all the answers

    What effect does transpiration have on plants?

    <p>Facilitates nutrient transport</p> Signup and view all the answers

    Through which structures does most transpiration occur in leaves?

    <p>Stomata</p> Signup and view all the answers

    Which process primarily helps in maintaining turgidity in plant cells?

    <p>Transpiration</p> Signup and view all the answers

    Which of the following conditions affects the rate of transpiration?

    <p>Light intensity</p> Signup and view all the answers

    Study Notes

    Ring Barking

    • Ring barking involves removing a strip of bark containing phloem from a woody plant trunk.
    • Aim is to demonstrate the vital role of phloem in transporting organic substances.
    • The experiment compares a ringed stem to a non-ringed stem over the span of one month.
    • Expected result: swelling and increased diameter above the ring, while below the ring, the stem withers and decreases in diameter.
    • Controlled environmental conditions are essential for accurate results.
    • Key tools include a sharp knife, measuring tape, and Vaseline to seal wounds and prevent air entry.
    • Observations support the conclusion that phloem is crucial for the transport of nutrients from leaves to other plant parts.

    Heterotrophic Nutrition - Food Tests

    • A range of food tests is conducted to identify the presence of starch, sugar, protein, and fats.
    • Iodine Test (Starch):
      • Blue-black color indicates starch presence when iodine is added to the food sample.
    • Benedict's Test (Sugar):
      • A color change from green to red upon heating indicates sugar presence, specifically glucose.
    • Biuret Test (Protein):
      • Purple coloration confirms protein presence when Biuret reagents (A and B) are added.
    • Emulsion Test (Fat):
      • Mixing food sample with ethanol and distilled water helps reveal fats through the formation of an emulsion.

    Transport in Plants

    • Xylem Structure:

      • Comprises xylem vessels and tracheids, both responsible for water conduction.
      • Thick-walled cells provide structural support and prevent collapse under tension.
      • Pits enable lateral movement of water and nutrients between cells.

    • Phloem Structure:

      • Consists of sieve tubes and companion cells, crucial for transporting organic substances like sucrose and amino acids.
      • Sieve plates facilitate the flow of sap from one cell to another.
      • Companion cells support sieve tube cells metabolically, enhancing nutrient transport.

    Translocation of Organic Substances

    • Organic substances in phloem, referred to as phloem sap, are vital for plant survival.
    • Translocation is the process by which these substances are moved from leaves to storage organs or growth regions.
    • Unique to phloem, translocation can occur in both upward and downward directions, unlike the unidirectional flow of xylem water.

    Water Transport and Transpiration

    • Transpiration:

      • Defined as the loss of water vapor through evaporation in plants.
      • Replaces lost water via roots absorbing moisture from soil.
      • Primarily occurs through leaf stomata, contributing significantly to nutrient transport and cooling.

    • Transpiration Stream:

      • Describes the continuous flow of water from roots to leaves, aided by atmospheric vapor loss.

    • Factors influencing transpiration rates include:

      • Light intensity
      • Temperature
      • Relative humidity
      • Air movement

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Explore the effects of ring barking in this Grade 11 Biology quiz. Learn how removing a ring of bark affects the transport of organic substances in trees by investigating the role of phloem. Understand the significance of phloem and its function in plant biology through this practical experiment.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser