The saguaro cactus has adapted in numerous ways to protect the water that it collects during rare rainstorms in the desert. It has a vast root system that allows the plant to absorb water near the surface during rainfall. It also has thorns that deter thirsty animals from getting inside the stem of the cactus and drinking its water. The saguaro cactus also has a very thick, barrel-shaped stem used for holding water. Plants that are adapted to these dry places like the saguaro cactus, are called xerophytes. They must collect, store, and conserve large amounts of water to grow and flourish in this harsh environment.

Which claim below does this passage support?

The saguaro cactus has adapted in numerous ways to protect the water that it collects during rare rainstorms in the desert. It has a vast root system that allows the plant to absorb water near the surface during rainfall. It also has thorns that deter thirsty animals from getting inside the stem of the cactus and drinking its water. The saguaro cactus also has a very thick, barrel-shaped stem used for holding water. Plants that are adapted to these dry places like the saguaro cactus, are called xerophytes. They must collect, store, and conserve large amounts of water to grow and flourish in this harsh environment.

Which excerpt from the text supports the idea that the saguaro cactus needs water to survive?

True or False: Plants need air, light, carbon dioxide, and water to grow.

Plants need ______________ from the air to complete the process of photosynthesis. They use this substance to create sugar and carbohydrates for nutrition and oxygen for cell respiration.

A group of students had two identical trays of soil, each with ten tomato seedlings planted in them. Tray A was placed in direct sunlight. Tray B was placed in the dark. Both trays were given the same amount of water. After four weeks, the students observed both trays. Which tray of seedlings will have the most growth?

When humans or animals need energy, they find some food to eat. Plants do not get food in the same way. Plants must take materials from the environment and use energy from sunlight to make glucose, an energy-rich sugar. Plants use water and air to make food. Plants absorb water from the soil and take it in through their roots. The water travels up the stem and reaches the cells in the leave. Plants must have water to allow the nutrients to be absorbed. Plants allow carbon dioxide from the air to enter their leaves through tiny holes, and it enters the leaf cells. Without air, plants would be missing one of the ingredients necessary to create glucose.

Plants take light energy from sunlight to make their food. Light energy is not a material; it is an energy. Leaf cells trap light energy and use it to convert water and carbon dioxide into sugar. The sugar is stored as chemical energy in the plant. When this process takes place, leaf cells release oxygen as a byproduct. This process is called photosynthesis.

Which piece of text evidence supports why plants need air to grow?

When humans or animals need energy, they find some food to eat. Plants do not get food in the same way. Plants must take materials from the environment and use energy from sunlight to make glucose, an energy-rich sugar. Plants use water and air to make food. Plants absorb water from the soil and take it in through their roots. The water travels up the stem and reaches the cells in the leave. Plants must have water to allow the nutrients to be absorbed. Plants allow carbon dioxide from the air to enter their leaves through tiny holes, and it enters the leaf cells. Without air, plants would be missing one of the ingredients necessary to create glucose.

Plants take light energy from sunlight to make their food. Light energy is not a material; it is an energy. Leaf cells trap light energy and use it to convert water and carbon dioxide into sugar. The sugar is stored as chemical energy in the plant. When this process takes place, leaf cells release oxygen as a byproduct. This process is called photosynthesis.

Which piece of text evidence from the passage supports the claim that plants need water to grow?

Plants and trees can grow in a wide variety of environments. Whether they grow in the desert or the rainforest, they all have one thing in common, air and water are necessary for life and growth. Depending on the plant’s adaptations, the amount of water needed to survive varies. Some plants, like those in the desert, need very little water to grow. Plants primarily get the materials for growth from the air and water. Sunlight provides the energy that is required to create food through photosynthesis. We often see plants in soil, but it isn’t necessary for growth.

Hydroponics is a system of growing plants without soil. Nutrients are added to water and delivered directly through a plant’s roots. Plants do not gain anything from the earth itself; they absorb nutrients from within the soil. If those nutrients are added to the water, and the plant is in the open air, then the soil is not needed. Plants take in carbon dioxide from the air and convert it into glucose through the process of photosynthesis, which is powered by sunlight. Hydroponics come in numerous forms: the plants can be hung vertically, and the roots are sprayed, or roots may be submerged in water through a series of tubs, containers, or even coconut husks!

How does this passage support the claim that air and water are vital to a plant's growth?

Which structures of a plant are used in the absorption of water and carbon dioxide from the air?

In 1642 most people thought that soil was the food for plants. Dr. Von Helmont from Belgium experimented on this topic for many years. He planted a 5-pound tree in a bucket with 200 pounds of soil. He watered the tree every day but did not add any more dirt. Von Helmont weighed the bucket after five years of allowing it to grow. The plant weighed 5 pounds, and the soil was 200 pounds at the beginning of the experiment. At the end of the research, in 1647, the plant weighed 169 pounds, and the soil was 199 pounds.

Based on Dr. Von Helmont's research, is soil the source of food for plants? Why or why not?