When plants grow they will bend to the light. The stem grows up, and the roots grow down.

“Tropism” is a phenonmemon of biology indicating growth toward or away, basically in reaction to an environmental stimulus. Water and light are vital for a plant to photosynthesise so it has mechanisms to ensure it can maximise uptake of these.

Think of a tropism as being a reaction. In plants light (phototropism), gravity (geotropism) water (hydrotropism), and touch may all play a factor.

Positive tropism is when the plant grows towards the stimulus, and negative tropism when the plant grows away from the stimuls. It’s generally accepted the stalk grows towards the light (phototropism), and the roots grow downard. (gravitropism)

Photo synthesis is the process of converting sunlight, water and carbon dioxide into glucose and oxygen. Is it human respiration in reverse?

The formula for phto sysnthesis is carbon dioxide + water + light > glucose + oxygen ? (is it light on chlorophyll?)

A vacular system in plants wouild transport the food, and water.

Xylem moves water and solutes from the roots to the leaves.

The phleom moves the glucose and amino acids made in the leaves? to the rest of the plant.

The phleom can move both ways where as the xylem can only move one way ? It uses active transpo osmois diffusionrt. Glucose is oconverted into sucrose in the “sources” of the plants. in the leaves ?

These two transport systems look different in the stem and the roots.

chloroplats producxe sugar

guard cells

Root have hairs which give them a large surface area for water aborbtion.

Le chatelier’s principle

Gibbs free energy