What provides from a plant seed structural support for upright growth?

Answer 1

Vascular tissue allows for the movement of water and nutrients throughout the plant, and provides structural support for upright growth. Compare the water conducting cells of Bryophytes, tracheids in gymnosperms, and vessels in angiosperms.

• Transition from water-dependent reproduction to water-independent reproduction.

Early plants relied on swimming gametes and were thus

required wet conditions to complete the life cycle. The seed plants do not require water either for fertilization or for survival of the zygote (the zygote is protected

from desiccation in the seed coat, and may lie dormant until the conditions are favourable for germination.) This allowed plants to colonize dry environments.

Also acceptable is an explanation of how the coevolution of flowers and animal pollinators allowed for expansion of range in many plants.

• Evolution of stomata, cuticle and pores.

This allowed the plant to control the loss of water in arid environments.

• Evolution of lignin and woody skeletons.

This allowed the plant to grow upright and withstand damage from environmental conditions.

• Evolution and elaboration of roots and leaves.

Roots both anchored the

plant and absorbed water and nutrients from the soil. Elaboration of leaves increased rates of photosynthesis as a response to increased competition for

light.

Answer 2

CELL WALL The cell wall surrounds the cell membrane of a plant cell. The cell wall is made of a nonliving material called cellulose [SEL-yoo-lohs]. The cell wall is more rigid (stiff) than the cell mambrane. It gives a plant cell its stiffness. It also gives it its shape.

Answer 3

Stem