Scientific Method - Yeast Experiment

The ______ is a microorganism single-celled fungi called Saccharomyces cerevisiae. It is the main ingredient added to flour to make bread.

What happens when you knead the dough?

Why do think that the hotter the dough, the faster it rises?

If you leave the dough growing for a few more hours, will the yeast activity continue or will it stop?

The temperature in the refrigerator at 4-5°C is the most active for yeast.

At what temperature is the yeast most active?

What are the variables in this experiment?

Which hypothesis was correct?

What are the possible controls in many ecological and geological investigations?

According to your observations, what is the role of temperature in this study?

Match the following terms with their definitions:

Scientific Method - Yeast and Dough

Scientific Research Steps:
- Make observations.
- State a problem.
- Formulate a hypothesis.
- Design an experiment.
- Analyse results.
- Share conclusions.
Yeast Experiment:
- Materials:
  - Fresh yeast tablets
  - Flour
  - Water
  - 3 containers
  - Marker
  - Thermometer
- Procedure:
  - Dilute 25g yeast in 200cm³ warm water
  - Combine flour, water, and yeast, knead dough
  - Divide dough into 3 pieces, place in containers
  - Mark heights, place containers in different temps
    - Refrigerator (4-5°C)
    - Room temperature
    - Water (60-70°C)
  - Record height every 5 minutes.
- Variables (in experiment):
  - The independent variable is the temperature.
  - Variables kept constant: amount of dough, humidity, light, and time.
- Hypothesis Example: "The hotter the dough, the faster it rises."
Analysis:
- Observe most active yeast temperature (4-5°C, room temp, or 60-70°C).
- Observe how long yeast keeps activating in 60°C and fridge samples after reaching room temp.
- Determine the correct hypothesis of the most suitable temp

Variables and Observational Studies

Variables in Experiments:
- Independent variable: changed to see its effect
- Dependent variable: measured to see the effect of independent
- Controlled variable: remain same in all trials.
Field Studies:
- Ecological, geological studies
- Observing in natural environment
- Variables difficult to control

Temperature and Plant Growth (Observation Study)

Example: The image shows plant growth at different elevations.
Temperature Role: Altitude affects temperatures.
The role of temperature in this study is to observe how plants grow at different natural temperatures.

Explore the steps of the scientific method through a hands-on yeast and dough experiment. Learn how to make observations, formulate hypotheses, and analyze results in different temperature conditions. This quiz will test your understanding of variables and the experimental process.