One of the three main functions of stems is to

Many cacti, such as saguaros and barrel cacti, have large stems and no leaves. What function of leaves is taken on by the stems of such cacti?

Oxygen and carbon dioxide move in and out of a leaf through the

In many plants, stomata are found only on the lower surface of the leaf. The most likely explanation for this fact is that

In Figure 24–2, which fruit or fruits would you expect to be dispersed by animals?

A period of dormancy can allow seeds to germinate

In most plants, which organs are adapted to capture sunlight for photosynthesis?

If some of the xylem of a young oak tree were destroyed, it would most likely interfere with the tree’s ability to

Vascular tissue in plants consists of

The outer covering of a plant consists of

Which of the following are areas of unspecialized cells in which mitosis produces new cells that are ready for differentiation?

Damage to which area of the root shown in Figure 23–2 will prevent the root from growing longer?

The root cap is a tough structure that protects the

Unlike roots, stems

During primary growth, a stem

What might a thin tree ring indicate?

Most of the photosynthesis in plants takes place in the

The flat structure of a leaf blade enables its function as a photosynthetic organ by

Look at Figure 23–3. Which letters indicate cells in which a large number of chloroplasts would likely be found?

In Figure 23–3, which letter points to the structure through which water is lost during transpiration?

Through which plant structure does water move by capillary action?

In angiosperms, pollen grains are produced in

Which of the following is NOT part of the female structure of a flower?

In angiosperms, flowers are adaptations for reproduction. Which of the following does NOT usually describe flowers that are pollinated by animals?

Seeds that are spread by wind and water usually are

A period during which the embryo of a seed is alive but not growing is

The plant embryo in a seed begins to grow again during

Interpret Visuals In Figure 23–3, look at structure F. What two types of tissues make up this structure?

Interpret Visuals Which label points to the part of the flower in Figure 24–4 that produces pollen grains? What is the name of this structure?

Interpret Visuals Which structure in Figure 24–4 receives pollen during pollination? What is the name of this structure?

When a plant responds to touch such as a grape vine wrapping around a branch.

Which of the following is true of the bryophytes?

All plants exhibit alternation of generations. This means their life cycle

The xylem generally transports _____, whereas the phloem transports _____.

What structures in the animal body are the xylem and phloem most like?

What structures in the animal body are the equivalent of the stomata and guard cells?

The femur (thigh) bone in a human has the same function as which part in a tree?

The elongation of roots and stems is known as

Vascular cambium is responsible for

Many everyday processes in plants operate rhythmically on a daily, monthly or

annual basis. Plants also show longer cycles of behavior that are influenced by day

length. This response to day length is called...

The _______________ ultimately matures into a fruit.

In the evolution of plants onto land, sporophytes became dominant over gametophytes due primarily to what adaptation?

Cells that regulate the movement of carbon dioxide into the plant and the movement of water and oxygen out of the plant through stomata are:

During pollination, pollen is transferred to the _____.

Which is a result of double fertilization in angiosperms?

Which of the following will be responsible for primary growth in plants?

Which type of meristem tissue is located between the bark and the wood of a woody stem?

What causes water to fill the xylem pipeline completely, from the roots to the leaves, and to resist any separation?