View source for GCSE Biology Required Practical: Tropic Effects on Seedling Growth

==Key Stage 4==
===Meaning===
Investigate the effects of [[light]] or [[gravity]] on the [[germination]] and growth of seedlings.
===Method===
Investigate the effects of [[light]] on the growth of seedlings.
*[[Independent Variable]] - Light intensity.
*[[Dependent Variable]] - Height of the seedlings.
*[[Control Variable]]s - Orientation of the seeds (never turned upside down it tilted). Abundant water for all seedlings. Same temperature for all seedlings.

#Place cotton wool lining the bottom of three petri dishes.
#Add water to the petri dishes.
#Place ten mustard seeds into each petridish allowing them to be spread apart from one another.
#Allow the mustard seeds to [[germinate]].
#Once the seeds have germinated remove any seeds that have not germinated then make sure all petri dishes have the same number of germinated seeds.
#Place 1 petri dish in direct sunlight, 1 in the shade and 1 in a dark cupboard, all in the same room.
#Use a ruler to measure the height of seedlings every day for 7 days. Each day ensure there is sufficient water in the cotton wool for the seedlings to grow.


Investigate the effects of [[gravity]] on the growth of seedlings.
*[[Independent Variable]] - Orientation of the seedlings.
*[[Dependent Variable]] - Height of the seedlings.
*[[Control Variable]]s - Light received by the seedlings (all kept in out of direct sunlight). Abundant water for all seedlings. Same temperature for all seedlings.

#Place cotton wool lining the bottom of two petri dishes.
#Add water to the petri dishes.
#Place ten mustard seeds into each petridish allowing them to be spread apart from one another.
#Allow the mustard seeds to [[germinate]].
#Once the seeds have germinated remove any seeds that have not germinated then make sure all petri dishes have the same number of germinated seeds.
#Place both petri dishes carefully on their side, not allowing any seeds to fall out of position. Add an arrow to both pointing down.
#Every day rotate one of the petri dishes to be upside down from the previous day.
#Use a ruler to measure the height of seedlings every day for 7 days. Each day ensure there is sufficient water in the cotton wool for the seedlings to grow.