5090/42/NOV23 VIDEO 1 Q1 AND Q2 EXPLAINED

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  • Опубліковано 28 вер 2024
  • O LVL BIOLOGY
    PAPER 4 SKILLS

КОМЕНТАРІ • 12

  • @SumairaNaveed-oz3ul
    @SumairaNaveed-oz3ul 4 місяці тому +18

    Best of luck everyone for tomorrow's exams 🙌❤

    • @phantom0491
      @phantom0491 4 місяці тому

      U too❤

    • @mnpking7254
      @mnpking7254 4 місяці тому

      me watching the papers just before a hour of paper 😂😭

  • @jamalkashif107
    @jamalkashif107 7 місяців тому

    mam i want to take your classes plzz emergencyy

  • @haamailfaisal7914
    @haamailfaisal7914 4 місяці тому +7

    Hope This Helps
    Good Luck With Your Caie's!!!!
    [00:00] Paper 4 is an alternative to practical for 509 level biology paper 42
    - Paper 4 is for 40 marks and lasts for 1 hour
    - Question 1 investigates the effect of using an insulating material on heat loss from an animal
    - Two test tubes were used, one with insulation and one without
    - Both test tubes were filled with water only up to the marked line to ensure the same volume of water was added to each
    - Water was not filled right up to the top to prevent water from overflowing when adding the thermometer
    [02:25] The experiment involves filling test tubes with water and recording temperature changes over time
    - Water is filled up to a marked line to prevent overflow when adding a thermometer
    - Temperature readings are recorded every 2 minutes for 10 minutes in a notebook
    - Insulation is used in some test tubes to observe its effect on heat loss
    - Results are recorded in a table without writing degrees Celsius in every column
    - The difference in temperature is calculated to describe heat loss and insulation's effect
    [04:53] Temperature decreases with time, insulation reduces heat loss, and heat loss is faster at the start
    - Temperature decreased from 73 to 59 and from 66.5 to 46.5
    - Insulation caused less temperature fall (66.5 to 46.5) compared to without insulation (73 to 59)
    - Heat loss was faster at the start, with a difference of 6.5 to 60, then 6, 5, 3, 2, and 1.5
    [07:20] Design an investigation to discover the effect of different surrounding water temperatures on the loss of heat by humpback whales using test tubes filled with water
    - Test tubes should start with the same volume and temperature of 38°C
    - Use a thermostatically controlled water bath to maintain temperature control
    - External temperature can represent cold polar or warm equatorial water
    [09:47] Investigation on the effect of different water temperatures on heat loss in a test tube representing veal
    - Test tube filled with water represents veal
    - Minimum three external temperatures needed: 30°C, 34°C, and 38°C
    - Record temperature in the test tube at specific time intervals (minimum 5 minutes)
    - Compare temperature change for each external temperature
    - Investigate the effect of temperature in a water bath on heat loss
    [12:14] Whales maintain a constant body temperature of 38 degrees, making the given example irrelevant
    - Whales' metabolic rate increases to maintain body temperature
    - Human body temperature is maintained through external factors like clothing and heating
    - The pulse oximeter measures heart rate and oxygen percentage in the blood
    - The device fits on the finger and is used to investigate the effect of exercise
    [14:41] Students recorded pulse oximeter readings before and after exercise, and graphed heart rate against time
    - Readings were taken at 0, 1, 2, 7, 8, 9, and 10 minutes
    - Heart rate and percentage of blood oxygen were recorded
    - The first column of the table is always an independent variable and goes on the x-axis
    - Graph should connect points with ruler-straight lines, going through a designated point
    [17:06] Instructions on how to plot heart rate and blood oxygen percentage on a graph
    - Label the x-axis with time in minutes from 0 to 10
    - Label the y-axis with heart rate in beats per minute
    - Use 75% of the graph and start the scale from 60
    - Plot all seven points correctly and join them with ruler lines
    - Fully label the graph to earn all four marks
    [19:34] Drawing two lines on a graph to identify the exercise period earns two marks, but it's not valid to determine heart rate at 5 minutes
    - Drawing a line from the start of the exercise at 2 minutes and another from the end at 7 minutes earns two marks
    - No data between 2 and 7 minutes means a straight line doesn't show changes in heart rate during exercise
    - Heart rate increase during exercise is not likely to be linear, so it's not valid to determine heart rate at 5 minutes
    [22:01] Heart rate increases during exercise from 2 to 7 minutes and returns to resting rate at 10 minutes
    The percentage of oxygen in blood only changes by 1% between 98 and 99%
    - Changes in breathing rate and depth could explain percentage oxygen levels during exercise

  • @MehwishButt-y2x
    @MehwishButt-y2x 4 місяці тому +5

    Who's here for tomorrow's p4 😭 you n I

  • @harshaninadeeka8740
    @harshaninadeeka8740 5 місяців тому +2

    Mam when will you be releasing a revision paper for this year exams like you did last year

  • @swordyt3964
    @swordyt3964 4 місяці тому

    Why less than 38?

    • @phantom0491
      @phantom0491 4 місяці тому

      releate with polar enviornment as temp is cold in polar region