Photosynthesis Review 1

Students had been tracking healthy leaves on a plant for 10 days. The plant had lots of sunlight. The plant was watered each day at first, but then stopped. What statement is true about the gradual changes in the leaf count?

• Adding water inconsistently increases leaf count.

• Adding water consistently decreases leaf count.

• Adding water consistently increases leaf count.

• Adding water has no effect on the leaf count.

A class is divided into two groups. They are studying plants and testing different methods for growing them. On Friday, the teacher instructs each group to do the final measure of their plants. Based on the evidence, what can you conclude about plants?

• Plants without sunlight grow more than the ones with sunlight.

• Plants with sunlight and air grow the most.

• Plants without sunlight and without air grow the most.

• Plants with air grow, but plants with no sunlight grow the most.

The idea that plants do not need soil to grow is supported by which of the following observations?

• Plants remain green for several hours after being removed from the soil.

• Different types of plants grow better in different types of soil.

• Some plants are grown in containers with nothing but water.

• When plants die, some of their nutrients are returned to the soil.

Kyler brought home a new plant from the nursery. She put it near the window in her room where it would get lots of sunlight. She knew that, like all producers, plants need energy to make food. They also need matter. Where does this matter come from?

• from sunlight

• from soil

• from animals

• from air and water

In his famous experiment, Jan van Helmont measured the mass of a small willow tree seedling and the mass of a pot of dry soil. The willow tree was planted in the soil, and only water was added as the tree grew. After five years, the mass of the soil and the willow were measured again. What data from this investigation supports the claim that soil does not provide most of the materials a plant needs to grow?

• The mass of the dry soil was greater than the tree after it grew.

• After the willow tree grew, the soil lost 0.1 kg of mass.

• The willow tree gained mass, but the soil lost almost no mass.

• The amount of mass the willow tree gained during the five years was 74.7 kg.