Question 1

A red-light photoreceptor in plants is called

Accepted Answer

A)  cryptochrome. 
B)  phototropin. 
C)  phytochrome. 
D)  zeaxanthin. 
E)  ethylene.

Question 2

A botanist is studying a newly discovered plant that is native to Norway.Which of the following would be the earliest indication that gibberellins play the same role in this plant that they play in flowering and reproduction in cabbage?

Accepted Answer

A)  Leaf senescence 
B)  Elongation of the stem 
C)  The shape of the flowers 
D)  The size of the fruit 
E)  The number of seeds per fruit

Question 3

Refer to the figure below, illustrating early studies of phototropism.  After blindfolding different parts of the seedling and watching the response to a light stimulus, the Darwins concluded that

Accepted Answer

A)  seedlings in natural conditions do not respond to the direction of a light stimulus. 
B)  the hormone auxin detects the direction of a light stimulus. 
C)  the part of the plant that detects the direction of a light stimulus is located at the base of the shoot. 
D)  the part of the plant that detects the direction of a light stimulus is located in the roots. 
E)  the part of the plant that detects the direction of a light stimulus is located in the shoot tip.

Question 4

The action of the plant hormones auxin and gibberellin

Accepted Answer

A)  is mediated by identical signal transduction pathways. 
B)  requires specific receptors for each hormone in the plasma membrane. 
C)  involves the switching on of genes by similar mechanisms. 
D)  involves activation of a transcription factor by removing a repressor. 
E)  does not require receptor proteins.

Question 5

Application of _______ to leaves can keep them green and delay senescence.

Accepted Answer

The answer of Application of _______ to leaves can keep...

Question 6

Refer to the diagram below showing cereal grain germination.  Wheat grains are processed to produce flour before germination occurs.Which part of the seed is used to mill white flour (which is mostly starch)?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  E

Question 7

Which compound is not a major group of plant hormones?

Accepted Answer

A)  Gibberellins 
B)  Auxins 
C)  Anthocyanins 
D)  Cytokinins 
E)  Abscisic acid

Question 8

A plant part (such as a root) that responds to gravity by growing downward is said to be _______.

Accepted Answer

The answer of A plant part (such as a root)...

Question 9

Auxin produced by mature leaves prevents the death of cells in the _______ at the base of the petiole.

Accepted Answer

A)  mesophyll 
B)  cortex 
C)  epidermis 
D)  abscission zone 
E)  xylem

Question 10

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 11

It is thought that auxins control growth by cell _______.

Accepted Answer

The answer of It is thought that auxins control growth...

Question 12

Refer to the diagram below showing cereal grain germination.  Identify the molecules indicated by F in seed 4.What is their role in relation to structure C?

Accepted Answer

The answer of Refer to the diagram below showing cereal...

Question 13

Researchers used a genetic screen to identify a blue-light-insensitive mutant Arabidopsis plant strain, then identified the gene for a blue-light receptor protein.Name the photoreceptor involved, and explain its role in plant behavior.

Accepted Answer

The answer of Researchers used a genetic screen to identify...

Question 14

In an experiment for this course, you are told to remove the shoot apical meristem of a sunflower, and you see that this leads to outgrowth of branch shoots.In order to reestablish apical dominance you would then apply _______.

Accepted Answer

The answer of In an experiment for this course, you...

Question 15

When germinating grass seeds are stimulated by gibberellins, the stimulation specifically increases enzyme production by the

Accepted Answer

A)  aleurone. 
B)  mesophyll. 
C)  cotyledons. 
D)  endosperm. 
E)  seed coat.

Question 16

A scientist is studying seeds from a species of sundew native to Western Australia.These seeds need to be treated with smoke before they can imbibe and germinate.This suggests that _______ for the seeds to germinate.

Accepted Answer

A)  seed dormancy must be broken 
B)  the radicle must emerge from the seed 
C)  water must be excluded 
D)  oxygen must be excluded 
E)  cell division must increase greatly

Question 17

Each cocklebur fruit contains two seeds that are kept dormant by two different mechanisms.Why might having two mechanisms of dormancy be advantageous to cockleburs?

Accepted Answer

The answer of Each cocklebur fruit contains two seeds that...

Question 18

Refer to the figure below.  The leaf on the left is turning yellow because it is experiencing a natural process known as

Accepted Answer

A)  phototropism. 
B)  photomorphogenesis. 
C)  quiescence. 
D)  etiolation. 
E)  senescence.

Question 19

Describe the circumstances under which it would be advantageous for a species to have the dormancy of its seeds broken by fire.

Accepted Answer

The answer of Describe the circumstances under which it would...

Question 20

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...

Exam 36: Regulation of Plant Growth