IB Biology Topic B3.2.7 Transport of Water from Roots to Leaves During Transpiration Revision Notes (SL/HL)

IB Biology Topic B3.2.7 Transport of Water from Roots to Leaves During Transpiration Revision Notes (SL/HL) | RevisionDojo

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Transpiration Pulls Water from Roots to Leaves

Definition

Transpiration

Transpiration is the loss of water vapor from the aerial parts of a plant, primarily through tiny pores in the leaves called stomata.

Water is lost as vapour from the leaves, and this loss pulls a continuous column of water up from the roots.
This whole movement of water up the plant is called the transpiration stream.
The water travels upward through the xylem vessels, the dead tubes that run from root to leaf.

Evaporation in the Leaf Starts the Pull

Water absorbed from the soil travels up through the roots, into the xylem, and into the leaf cells.
Inside the leaf, water evaporates from the cell walls of the spongy mesophyll into the air spaces.
1. The water vapour then diffuses out through the stomata, tiny pores on the leaf surface, and into the atmosphere.
2. This evaporation and diffusion of water from the leaf is transpiration.

Tension in the Xylem Draws Water Upward

As water evaporates from the leaf cell walls, it creates a negative pressure (tension) inside the xylem.
This tension pulls more water up the xylem vessels toward the leaves.
The water column holds together because of cohesion, the attraction between water molecules caused by hydrogen bonding.
Water also sticks to the walls of the xylem by adhesion, which helps support the column as it rises.

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Note

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Excepteur sint occaecat cupidatat non proident

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Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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Transpiration Pulls Water from Roots to Leaves

Definition

Transpiration

Transpiration is the loss of water vapor from the aerial parts of a plant, primarily through tiny pores in the leaves called stomata.

Water is lost as vapour from the leaves, and this loss pulls a continuous column of water up from the roots.
This whole movement of water up the plant is called the transpiration stream.
The water travels upward through the xylem vessels, the dead tubes that run from root to leaf.

Evaporation in the Leaf Starts the Pull

Water absorbed from the soil travels up through the roots, into the xylem, and into the leaf cells.
Inside the leaf, water evaporates from the cell walls of the spongy mesophyll into the air spaces.
1. The water vapour then diffuses out through the stomata, tiny pores on the leaf surface, and into the atmosphere.
2. This evaporation and diffusion of water from the leaf is transpiration.

Tension in the Xylem Draws Water Upward

As water evaporates from the leaf cell walls, it creates a negative pressure (tension) inside the xylem.
This tension pulls more water up the xylem vessels toward the leaves.
The water column holds together because of cohesion, the attraction between water molecules caused by hydrogen bonding.
Water also sticks to the walls of the xylem by adhesion, which helps support the column as it rises.

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

IB Biology Topic B3.2.7: Transport of Water from Roots to Leaves During Transpiration Notes

Transpiration Pulls Water from Roots to Leaves

Evaporation in the Leaf Starts the Pull

Tension in the Xylem Draws Water Upward

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Transpiration Pulls Water from Roots to Leaves

Evaporation in the Leaf Starts the Pull

Tension in the Xylem Draws Water Upward

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics