WorksheetsBiology Concepts and Experimental Techniques
Total questions: 15
Worksheet time: 8mins
In a scientific experiment, what is the variable that is changed by the experimenter?
Independent variable
Dependent variable
Control variable
Extraneous variable
What is a method to reduce parallax error when reading a measurement from a ruler or measuring cylinder?
Taking multiple readings and calculating a mean
Ensuring your eye is in line with the measurement
Using a digital measuring device
Repeating the experiment on different days
When preparing an onion skin sample for microscopy, what is the purpose of adding a drop of iodine?
To prevent the sample from drying out
To increase the magnification of the cells
To stain the cells for better visibility
To preserve the cells from decay
When starting to view a specimen under a microscope, which objective lens should be used first?
The highest magnification objective lens
The lowest magnification objective lens
Any objective lens can be used first
The objective lens with the largest field of view
In an osmosis experiment with potato cylinders, what does the point where the line of best fit meets the x-axis on a graph of percentage change in mass vs. sugar concentration represent?
The maximum water absorption by the potato cells
The concentration of sugar in the potato cells
The point where the potato cells burst
The minimum water loss from the potato cells
In an enzyme experiment involving starch, what color change indicates the continued presence of starch when iodine is added?
Orange to black/dark purple
Blue to green
Yellow to orange
Clear to cloudy
Which reagent is used to test for the presence of protein in a food sample, and what color change indicates a positive result?
Iodine solution, turning orange to black
Benedict's solution, turning blue to brick red
Biuret's reagent, turning blue to purple
Cold ethanol, turning clear to cloudy
What is the expected result when testing for lipids (fats) using cold ethanol followed by mixing with water?
The solution turns black
The solution turns green
The solution turns purple
The solution turns cloudy
What is the independent variable when investigating the relationship between light intensity and the rate of photosynthesis?
The volume of oxygen produced.
The number of bubbles released.
The distance between the plant and the light source.
The amount of sodium hydrogen carbonate added.
How does light intensity change if the distance from the light source is doubled?
It doubles.
It halves.
It becomes one-quarter.
It remains the same.
Which of the following is a correct formula to calculate reaction time (t) based on the distance (s) a ruler drops, where 'a' is acceleration due to gravity?
t = s / a
t = 2s / a
t = sqrt(2s / a)
t = sqrt(s / 2a)
What is the purpose of using a random number generator when placing quadrats to estimate an organism's population?
To ensure all organisms are counted.
To make the sampling process faster.
To avoid bias in selecting sampling locations.
To measure the exact area of the habitat.
Why is it important to sterilize equipment using a flame when preparing bacteria cultures?
To make the equipment easier to handle.
To prevent contamination from airborne microbes.
To increase the growth rate of bacteria.
To make the agar solidify faster.
What is the term for the growth of plant roots downwards in response to gravity?
Phototropism
Hydrotropism
Geotropism
Thigmotropism
When investigating the decay of milk using lipase, what happens to the enzyme's activity if the temperature is too high?
The enzyme's activity increases indefinitely.
The enzyme denatures and its activity decreases.
The enzyme becomes more stable.
The enzyme changes color.
