3.3 Review- Orientation in Plants

Which of the following is NOT true about tropisms

• They are growth repsonses to stimuli in plants

• They produce fast and permanent responses

• most plant growth occurs from region called meristem

• positive tropism would take place in the direction of the stimulus

Which plant hormone, produced in shoots and roots, promotes cell elongation and differentiation?

• Gibberelins

• Auxin

• ABA

• Ethene

Which plant hormone promotes fruit ripening?

• ABA

• Cytokinens

• Giberellins

• Ethene

Which of the following is not true?

• The tip of the plant is most important for detecting light

• Light signals pass down the unshaded side of the plant shaft

• Light signal is water soluble

• Light signal does not require intact cells

These organelles sink in response to gravity

• Auxins

• Geoliths

• Statoliths

• mitochondria

Which of the following is NOT true about geotropism?

• It causes upward growth in shoots and downward growth in roots

• In shoots, The statolith sinks and causes auxin to accumulate on the upper side

Which of the following is NOT true about nastic responses

• They are rapid and reversible responses to stimuli

• caused by changes in ion channels of pulvini cells

• Linked to osmotic changes and turgor pressure

• They are not proportional to the stimulus

The movement of a plant part, usually flower petals, in response to light is called

• photonasty

• thigmonasty

The movement of a plant part in response to the touch of an object is called

• photonasty

• thigmonasty

The sensitive plant mimosa pudica which is also known as touch-me-not is an example of

• photonasty

• thigmonasty