Plant Response to Signals

Question 1

Hormones are ___________ substances, that are made in one part of _________ and take effect in ___________, and are effective in __________ concentrations.

Answer 1

chemical

body

another part

small, minute

Question 2

In Reception, hormones are __________ by receptors in the cell membrane.

Answer 2

detected

Question 3

This signal is moved to the nucleus or mechanism in __________.

Answer 3

cytoplasm

Question 4

In an induced response, the signal turns on or __________ in the cell.

Answer 4

off

Question 5

In a ___________ response, the signal directly activates a mechanism, without the need of activation genes.

Answer 5

constitutive

Question 6

Tropisms are a __________ response changing the __________ of growth in response to a particular ___________.

Answer 6

constitutive

direction

stimulus

Question 7

In gravitropism, plant roots grow __________, and stems grow ___________.

Answer 7

down

up

Question 8

Tendrils on pea plant leaves curl around objects in ________-tropism.

Answer 8

thigomo-

Question 9

The tendrils are responding to a “sense” of _____________.

Answer 9

touch

Question 10

In Phototropism, plants “bend” by growing ___________ the light source.

Answer 10

toward

Question 11

Phototropism is mediated by the hormone ___________.

Answer 11

auxin

Question 12

This hormone is in higher concentrations on the __________ side of the coleoptile (stem).

Answer 12

shaded

Question 13

Phototropism:

The hormones have _____________ movement inside the stem.

Answer 13

basipetal

Question 14

Phototropism:

The hormone is sensitive to _________ (color) light, using _________ receptors.

Answer 14

blue

phototropin

Question 15

Once inside the cell, the hormone activates __________ pumps which make the cell wall more ___________.

Answer 15

proton

acidic

Question 16

The lowering pH of the cell wall activates the enzyme _________ which clips smaller cross connections between the __________ microfibrils.

Answer 16

expansins

cellulose

Question 17

The lower pH also cause water uptake increasing the __________ pressure on the loosened cell wall.

Answer 17

turgor

Question 18

In response, the thin primary cell wall ___________ enlarging the cell.

Answer 18

elongates

Question 19

The hormone moves ____________ (direction) in the stem.

Answer 19

down

Question 20

In its protonated from in the cell wall it is easy for the hormone to move __________ of the cell.

Answer 20

through

Question 21

The hormone can only exit a cell by ___________ proteins located at the _________ of the cell.

Answer 21

auxin carrier

bottom

Question 22

There is a lot/little lateral movement of the hormone in the stem.

Answer 22

little

Question 23

In apical dominance, the ___________ buds are inhibited from growing by the _________ meristem.

Answer 23

axillary

apical

Question 24

The inhibiting hormones are ___________ produced in the ___________.

Answer 24

auxin

meristem

Question 25

A growth promoting hormone __________ is produced in the __________.

Answer 25

cytokinin root

Question 26

"Pinching back", removing the shoot tips, makes the plant grow ____________.

Answer 26

bushier

Question 27

Pruning a rose bush or fruit tree results in more ___________ in the spring.

Answer 27

growth/flowers

Question 28

After pruning, there is a change to the hormone ratio, with a relative decrease in __________(hormone) and an increase in __________(hormone).

Answer 28

auxin cytokinin

Question 29

In our annual grasses, the seed coat has ___________(hormone) which inhibits/promotes germination.

Answer 29

ABA inhibits

Question 30

These seeds germinate after the inhibitor hormone is removed by ____________.

Answer 30

rain

Question 31

Germination is promoted by the hormone ___________ coming from the ____________.

Answer 31

gibberillin embryo

Question 32

In some plants like peas, dwarfism can occur when a mutation disrupts the production ____________(hormone).

Answer 32

gibberillin

Question 33

In biennial plants the first seasons of growth have very short stems due to a low/high level of _________hormone. In the second season the plants “bolt” by producing a low/high level and the stem grows very tall and flowers.

Answer 33

low GA high

Question 34

Fruit ripening in some plants like apples, is triggered by ____________(hormone) which moves as a ___________.

Answer 34

ethylene gas

Question 35

In ripening, organic acids are converted into __________ and the middle lamella(pectin layer) _________ making the fruit soft.

Answer 35

sugar breaks down

Question 36

One fruit ripening causes other fruit to ___________ and produce more __________.

Answer 36

ripen ethylene

Question 37

The ethylene production is an example of a ___________ feedback.

Answer 37

positive

Question 38

The triple response is caused by a seedling encountering ____________ in the soil.

Answer 38

obstacle

Question 39

This causes the seedling to produce ____________(hormone)

Answer 39

ethylene

Question 40

This in turn triggers 3 growth changes:

Answer 40

i. slow elongation ii. thicken iii. grow sideways

Question 41

Plants use ___________ receptors in their membranes to determine the season of year.

Answer 41

phototropins

Question 42

These receptors are sensitive to __________ light in nature.

Answer 42

blue and red

Question 43

In lab, the receptor can be reversed by exposing them to ___________ light.

Answer 43

far red

Question 44

At the end of a day, all the phytochrome will be in the __________ form.

Answer 44

Pfr

Question 45

Slowly in darkness, the phytochrome reverts to the ___________ form.

Answer 45

Pr

Question 46

A summer blooming plant will flower if the _________ time is longer/shorter than a critical length.

Answer 46

night shorter

Question 47

A winter blooming plant will flower if the __________ time is longer/shorter than a critical length.

Answer 47

night longer

Question 48

In _____________ phytochrome senses light and triggers the potato stem to green up and make leaves.

Answer 48

de-etiolation

Question 49

Lettuce seeds will ____________ if phytochrome detects sufficient light levels.

Answer 49

sprout leaves

Question 50

Poison oak will grow as a shrub in full sun or a vine in the shade. The plant detects the quality of light (sun or shade) by using ___________ receptors.

Answer 50

phototropin

Question 51

These are induced/constitutive responses.

Answer 51

induced

Question 52

If a fungal pathogen infects a leaf, the plant initiates the __________ in the leaf which causes a local necrotic zone which may ___________ the pathogen.

Answer 52

enzyme attack

Question 53

This infected zone secretes ______________ which moves to the rest of the plant initiating the ________________.

Answer 53

methylsalicylic acid hypersensitive response

Question 54

An example of a plant molecular level/chemical defense:

Answer 54

opium poppy fruit

Question 55

An example of a plant organ level/mechanical defense

Answer 55

egg mimicry

Question 56

A parasitoid is a parasite that infects ______________.

Answer 56

a parasite on another organism

Question 57

In masting, a plant population ________________

Answer 57

massive blooms after several years of growth with no seeds