Cress Seed Growth Experiment Analysis

The video tutorial demonstrates a GCSE biology practical activity examining the effects of light on cress seed growth. It covers the setup of the experiment, where cress seeds are placed in petri dishes with varying light conditions. Over seven days, the growth of the seeds is measured and analyzed. The results show that seeds in no light grow taller initially but are less healthy, while those in full light are shorter but healthier. The experiment highlights the importance of light for photosynthesis and seedling health.

What is the first step in setting up the cress seed experiment?

• Labeling the petri dish

• Placing cotton wool in the petri dish

• Measuring the length of the cress seeds

• Adding water to the petri dish

How many cress seeds are used in each petri dish?

• 5

• 20

• 10

• 15

What is the dependent variable in this experiment?

• Amount of water added

• Type of cotton wool used

• Length of the cress seeds

• Number of petri dishes

Which light condition resulted in the tallest cress seeds after seven days?

• No light

• Partial light

• Alternating light

• Full light

Why do cress seeds initially grow taller in the dark?

• They are trying to reach light

• They receive more nutrients

• They have more space to grow

• They absorb more water

What happens to cress seeds if they remain in the dark for too long?

• They continue to grow healthily

• They start to photosynthesize

• They eventually die

• They produce more seeds

What is the main reason cress seeds in full light are shorter?

• They are in a smaller petri dish

• They have less water

• They don't need to stretch to find light

• They are overcrowded

How is the mean height of the seedlings calculated?

• By measuring the tallest seedling

• By adding all heights and dividing by the number of seedlings

• By measuring the shortest seedling

• By averaging the heights of the first three days

What is a key observation about the health of cress seeds grown in different light conditions?

• All seeds have the same health

• Seeds in full light appear healthier

• Seeds in partial light are the least healthy

• Seeds in the dark are healthier

What is the purpose of labeling the petri dishes?

• To track the light conditions each dish is exposed to

• To measure the amount of water added

• To identify the type of seeds used

• To record the date of the experiment