Neuroscientist Greg Gage takes sophisticated equipment used to study the brain out of graduate-level labs and brings them to middle- and high-school classrooms. Watch what happens when he connects the Mimosa pudica and a Venus flytrap to an EKG to show their electrical signals.

If a Venus fly and a mimosa trap produces a measurable electrical impulse this suggests that there may be other plants which can do the same thing.  Could this make an IA experiment?  There is some affordable equipment and a whole host of experiment ideas on Greg's website Backyard Brains

Trees talking to each other has become accepted knowledge but what do trees talk about? In the Douglas fir forests of McMurdo, this National Geographic explainer shows how trees “talk” to each other by forming underground symbiotic relationships—called mycorrhizae—with fungi to relay stress signals and share resources with one another.

This might be impossible to measure with any precision, but it has been shown that 'mother trees' or 'node' trees send sugars to their own offspring more than to other saplings.  Does this affect the growth of connected trees. Do isolated trees show different characteristics, or do they grow more slowly.  Could a study of trees on a hillside show a difference between isolated trees and trees in groups?

This nice video from a channel called Home and Garden in Vietnam shows how to grow roots and shoots from whole garlic bulbs. Because each bulb produces many roots in just a few days, biology teachers sometimes use these for experiments to see the cells of roots dividing by mitosis. The same method could also be used to investigate the conditions which lead to the most growth, be it temperature, light intensity, colour, or substances dissolved in the water, which may inhibit growth, or promote growth.  It may even be interesting to use this setup to see whether the growth of garlic has any anti microbial properties.

If garlic doesn't take your fancy, Home and Garden has lots of other practical and simple ideas for growing plants, seeds and more. Take a look at their channel here.

This is a surprising film which suggests three different ways to use waste banana peels. Any one of these ideas could be adapted into a Biology IA experiment. Simply by setting up a controlled experiment next to a treatment and measuring the results several research questions can be answered.

The Miyawaki method of growing small forests is spreading around the world, and many urban groups are using this method to plant trees in small urban locations, next to roads, in built up areas.  There are many videos showing projects in countries around the world and some make extraordinary claims; the trees absorb ten times more carbon dioxide, they grow faster than trees planted in traditional methods. enriching the soil with biomass helps the growth, the temperature in a forest is up to three degrees cooler, they grow thirty times more densely than traditional forest and contain a hundred times more biodiversity.
There are many timelapse videos of planted forests on youtube which could possible be used for data collection. Students may be lucky enough to live need some growing plantations and be able to visit them with consent of the owners. So much potential for an IA. There is an interesting introduction on Medium and not everyone agrees, as can be seen in this article in the Indian Economic Times

This video shows some athletes testing a special sports insole. This could easily form the basis of a Biology IA. It would be important to explain how the insole works, and to link this to biology, the muscles of the leg and foot as much as the properties of the insole.  The video shows six performance tests, and an adaptation of one of these test could make an IA. It would need some consideration of controlled variables.