Question

a student grows three identical plants but changes one structure in each:

• plant a: roots are trimmed short
• plant b: stem is damaged
• plant c: many leaves are removed

after several weeks, all plants show reduced growth, but the causes are different.
which claim best explains how each changed structure affected the plant?
a plant a could not absorb enough water; plant b could not move materials through the plant; plant c could not
b a could not reproduce; plant b could not store food; plant c could not anchor in the soil.
c plant a could not make food; plant b could not absorb water; plant c could not hold the plant upright.
d plant a could not get sunlight; plant b could not protect seeds; plant c could not take in minerals.

Explanation:

• Plant A: Roots are responsible for absorbing water (and minerals) from the soil. If roots are trimmed short, the surface - area for water absorption is reduced, so the plant cannot absorb enough water.
• Plant B: The stem has vascular tissues (xylem for water and mineral transport, phloem for food transport). A damaged stem disrupts the movement of materials (water, minerals, food) throughout the plant.
• Plant C (though the option is cut off in the original, but based on plant structure - function relationships): Leaves are the main site of photosynthesis (making food). Removing many leaves reduces the plant's ability to produce food (by reducing the photosynthetic surface area).

Option B is incorrect because roots are not for reproduction (flowers/fruits are in angiosperms), stems are not mainly for food storage (some stems like tubers store food, but the general function of the stem is support and transport), and leaves are not for anchoring (roots are). Option C is wrong because roots do not make food (leaves do via photosynthesis), stems do not absorb water (roots do), and leaves do not hold the plant upright (stems and roots for anchoring do). Option D is incorrect because roots are not for getting sunlight (leaves are), stems (in most cases) do not protect seeds (fruits do), and leaves are not for taking in minerals (roots are).

Answer:

A. Plant A could not absorb enough water; Plant B could not move materials through the plant; Plant C could not