Question 1

Darwin studied the plant response called _______ by "blindfolding" the coleoptiles of monocot seedlings.

Accepted Answer

The answer of Darwin studied the plant response called _______...

Question 2

A plant grows toward a directional light when auxin moves to the (lighted/shaded) _______ side.This has the effect of expanding the cell walls in that region, causing asymmetric growth and, thus, bending.

Accepted Answer

The answer of A plant grows toward a directional light...

Question 3

A scientist has planted the seeds of a desert shrub at different depths.The only seeds that have germinated are those closest to the surface.This is probably because the successfully germinated seeds were exposed to more

Accepted Answer

Seeds closer to the surface are exposed to more red light, which is known to promote germination in many plant species.

Question 4

The physiologically active form of phytochrome

Accepted Answer

The physiologically active form of phytochrome is P_fr, which is converted from P_r upon absorption of red light.

Question 5

The pigment protein phytochrome is thought to allow plants to detect photoperiod because

Accepted Answer

Phytochrome is converted into two different forms, Pr and Pfr, depending on the specific wavelengths of light it absorbs. This conversion is important for plants to detect and respond to changes in photoperiod.

Question 6

A type of seedless fruit commonly produced using artificially applied gibberellins is _______.

Accepted Answer

The answer of A type of seedless fruit commonly produced...

Question 7

The role of the hormone called _______ in phototropism was first indicated in studies carried out by Charles Darwin and his son, Francis.

Accepted Answer

The answer of The role of the hormone called _______...

Question 8

Phytochrome does not

Accepted Answer

Phytochrome is involved in light sensing and signaling, but it does not promote the formation of the apical hook during germination.

Question 9

Growth of a shoot tip toward the light, which is called phototropism, is thought to be mediated by the actions of _______.

Accepted Answer

The answer of Growth of a shoot tip toward the...

Question 10

Etiolated seedlings are produced by germinating seeds that are kept in total darkness.Plants that are kept in the dark will begin to synthesize chlorophyll after they are given a pulse of

Accepted Answer

Red light is effective in triggering the synthesis of chlorophyll in etiolated seedlings, as it activates phytochrome, a photoreceptor that regulates plant development in response to light.

Question 11

As Charles Darwin and his son discovered, blocking light from the _______ of a young wheat plant would prevent phototropism from occurring.

Accepted Answer

The answer of As Charles Darwin and his son discovered,...

Question 12

Which of the following light receptors is responsible for absorbing both blue and ultraviolet light?

Accepted Answer

Cryptochrome is responsible for absorbing both blue and ultraviolet light.

Question 13

If you had a friend who was involved in brewing beer at home, you could play a practical joke on him by spraying his barley seeds with a substance that inhibits the action of _______ to prevent the seeds from converting stored starch into sugars.

Accepted Answer

The answer of If you had a friend who was...

Question 14

Which of the following statements about phytochrome P_r is true?

Accepted Answer

The answer of Which of the following statements about phytochrome...

Question 15

Molecules that are active at small concentrations and regulate plant development are called _______.

Accepted Answer

The answer of Molecules that are active at small concentrations...

Question 16

Phototropin is a

Accepted Answer

Phototropin is a type of blue-light receptor. It is responsible for helping plants to grow towards light sources, and is involved in regulating the plant's phototropic response.

Question 17

In plant seeds that germinate in response to a brief pulse of light, _______ is most effective in triggering germination.

Accepted Answer

This phenomenon is known as the red/far-red reversible response and is controlled by the phytochrome photoreceptor. Red light (660nm) activates the phytochrome, which induces germination, while far-red light (730nm) inactivates the phytochrome, which prevents germination. Therefore, the most effective way to trigger germination in these types of seeds is to expose them to red light followed by far-red light.

Question 18

Any molecule that is moved from one end of the plant to another, like auxin, is said to have _______ transport.

Accepted Answer

The answer of Any molecule that is moved from one...

Question 19

A germinating grass seedling embryo produces gibberellins, which can signal the plant to mobilize stored _______.

Accepted Answer

The answer of A germinating grass seedling embryo produces gibberellins,...

Question 20

The effect of light on the growth and development of a plant is called

Accepted Answer

The effect of light on the growth and development of a plant is termed as photomorphogenesis. Photomorphogenesis refers to the light-induced changes in plant morphology, development, and gene expression, which occur independently of photosynthesis.

Quiz 36: Regulation of Plant Growth