3.1: Transition to Living on Dry Land
Plants are adapted to living on land where light is more available and carbon dioxide diffuses freely in
the air.
To conserve water, leaves and
stems [3, 4, & 5] are usually
covered by a waxy cuticle
Shoot Systems – Leaves [4]
perform photosynthesis and
gas exchange
[5] Stem supports the plant
and may perform
photosynthesis
Root System: Root also contain tissues that
transport those nutrients to the stem
Alga is supported by the
surrounding water. Whole alga
performs photosynthesis, absorbs
water, CO2, and minerals from the
water.
These additional adaptations allowed plants to move onto dry land.
1. A cellulose cell wall prevents plant cells from drying out and provides support.
2. Plants have a sporic life cycle (with alternation of generation)
3. Most plants enclose the embryo to protect it and keep it from drying out, and use wind to disperse
spores or seeds.
4. Vascular plants have tube-like, elongated xylem tissues that carry water and nutrients from the
roots and living phloem tissue that transp[orts the carbohydrates manfactured during photosynthesis
throughout the plant. Xylem tissue contains a tough support material called lignin, which allows trees
to grow to great heights.