Learn: Nutrition Minérale et Hydrique des Plantes

Welcome!Today we'll explore how plants obtain and utilise water and minerals for growth and survival. This process is essential for plants to carry out photosynthesis and other vital functions. Let's learn all about it!

What is nutrition minérale et hydrique?Plants need water and minerals for their survival. Water is absorbed through their roots by osmosis, while minerals are taken up by active transport. Both water and minerals are transported through specialised tissues called xylem and phloem.

Role of RootsThe roots of plants are adapted to maximise the absorption of water and minerals. They have tiny structures called root hairs, which increase their surface area to absorb more nutrients and water. This is critical for plant growth.

Water Absorption: OsmosisWater enters root cells by osmosis, which is the movement of water from a region of higher water potential to lower water potential across a selectively permeable membrane. This allows plants to absorb water from the soil and maintain hydration.

Mineral Absorption: Active TransportMinerals like nitrates and phosphates enter the roots by active transport. Unlike osmosis, active transport requires energy because it moves substances against their concentration gradient.

Transport in Xylem and PhloemOnce absorbed, water and minerals travel through the xylem, which carries water upwards to the leaves. The phloem transports sugars made during photosynthesis to other parts of the plant for storage or energy.

Environmental Effects on Water UptakeEnvironmental conditions like temperature, wind speed, and humidity affect the rate at which water is absorbed and transported in plants. High temperatures or low humidity can increase transpiration rates.

Adaptations for Water and Mineral AbsorptionPlants have evolved specific adaptations like extensive root systems, root hairs, and specialised xylem vessels to absorb and transport water efficiently. These features help them survive in different environments.

Review Time!Great work! You've learned about how plants absorb water and minerals, the roles of xylem and phloem, and environmental factors affecting these processes. Let's review these concepts.