Plant Structure and Function Assessment

How did the ancestors of plants, living in oceans, obtain their energy?

• By consuming smaller organisms.

• Through photosynthesis, converting sunlight, carbon dioxide, and water into sugar.

• By absorbing nutrients from the ocean floor.

• Through chemosynthesis, using chemical reactions for energy.

What was the primary advantage for early land plants that evolved to grow taller?

• To escape predators.

• To access more sunlight and outcompete smaller plants.

• To spread their seeds more widely.

• To absorb more carbon dioxide from the atmosphere.

What substance provided early plants with the rigidity and strength needed to grow tall on land?

• Cellulose

• Lignin

• Chlorophyll

• Water

What material, described as the biological equivalent of "steel-reinforced concrete," allowed the first trees to emerge?

• Bark

• Leaves

• Wood

• Roots

What is the name of the razor-thin circular zone of stem cells in a tree that grows inward and outward?

• Phloem

• Xylem

• Cambium

• Heartwood

Which part of the tree's internal structure is responsible for transporting water and nutrients upwards from the roots, and is primarily composed of dead cells?

• Phloem

• Cambium

• Bark

• Xylem

What is the process called when heat from the sun evaporates water from tiny pores in leaves, creating tension that pulls water up through the tree?

• Photosynthesis

• Respiration

• Transpiration

• Osmosis

What happens to sieve cells as they mature to perform their function?

• They develop strong cell walls to provide support.

• They grow larger and divide rapidly.

• They destroy their organelles and nuclei, becoming hollow.

• They develop chloroplasts for photosynthesis.

What is the role of companion cells in relation to sieve cells?

• They help sieve cells perform photosynthesis.

• They provide structural support to sieve cells.

• They keep sieve cells alive by sending energy and instructions.

• They transport water from the roots to the leaves.

What is the main function of sieve cells in a tree?

• To store water and nutrients.

• To transport sugars and signals throughout the tree.

• To protect the tree from damage.

• To produce new cells for growth.