Putting Roots Down

Multiple Choice

A plant's response to any stimulus

• dormancy

• tropism

• hibernation

• pollination

Multiple Choice

The movements in a plant in response to light

• phototropism

• geotropism

• hydrotropism

• thigmotropism

Multiple Choice

The diagram shows a plant growing near a window. How can the plant's reaction best be described?

• as condensation

• as transpiration

• as dormancy

• as tropism

Multiple Choice

The movement of roots toward the ground or the movement of stems away from the ground

• hydrotropism

• geotropism

• thigmotropism

• phototropism

Multiple Choice

Why does a plant stem grow upward away from the soil?

• positive geotropism

• positive thigmotropism

• negative geotropism

• negative hydrotropism

Multiple Choice

What causes plants to bend toward the sunlight?

• positive thigmotropism

• positive thigmotropism

• negative phototropism

• positive phototropism

Multiple Choice

Scientists on a space shuttle mission studying plant growth would probably see that the plants on the space shuttle do not grow in the same direction and pattern as those on Earth. Scientists working in space would MOST LIKELY be studying the effects of which of the following stimuli on plant growth?

• Gravity

• Oxygen

• Radiation

• Temperature

Multiple Choice

Billy orders a plant for his garden. When it was delivered, the roots and the plant stem were not growing straight out of the clay pot. Instead, the direction of their growth was in a 'sideways' direction. The diagram shows the direction the plant was growing when it was received by Billy.

Why is the most likely reason for the direction of the plant growth?

• The plant lost turgor pressure and changed it's growth direction.

• The plant was laid on it's side inside the package and geotropism caused the plant to change it's growth direction.

• The plant found light through the sealed package and phototropism caused the plant to change it's direction of growth.

• Plants normally grow in strange patterns until they reach a certain age.

Multiple Choice

Trees that grow in a forest tend to grow very tall, with few branches. The same species of tree grown in an open area tends to grow shorter and wider, with many branches. The stimulus responsible for these different growth patterns is the amount of —

• wind striking the tree

• light reaching the tree

• nutrients in the soil

• water in the ground

Multiple Choice

If the top portion of plants grow "up," explain why a small tree on a hillside does not grow straight out from the hillside?

• The tree is growing toward water.

• The tree is resting on the hillside.

• The tree is leaning toward the top of the hill so rain won't wash it off.

• The tree's roots and trunk are growing in response to gravity.