Explain why plants require a source of fixed nitrogen and howthey obtain it

How do the nitrogen-fixing genera Azospirillum and Rhizobium associate with plant roots?   Rhizobium stays on the outside of the roots of tropical grasses, while Azospirillum grows inside the roots of legumes. Azospirillum and Rhizobium both stay on the outside of roots. Azospirillum stays on the outside of the roots of tropical grasses, while Rhizobium grows inside the roots of legumes. Azospirillum and Rhizobium both grow inside specialized root cells.

Normally Transpiration is good for plants however in some cases it can lead to water stress how does it this

How are sugars transported in phloem? the formation of starch from sugar in the sink increases the osmotic concentration high turgor pressure in source sieve-tube elements pushes phloem sap to sink sieve-tube elements with low turgor pressure water is actively transported into the source region of the phloem to create the turgor pressure needed the combination of a high turgor pressure in the source and transpiration water loss from the sink moves solutes through phloem conduits

Explain how sugars move throughout a plant via the source-sink mechanism.

Describe various factors that affect plant growth (e.g. growth regulators,sunlight, nutrients, water, tropism), and explain by giving example, why someplants can live in the forest although they might not be exposed to the sun ‘nosunlight can reach them’.