Growth and Development 1

Question 1

Define development

Answer 1

the sum of all of the changes that plant goes through during its life-cycle

Question 2

what is the sequence of events required by development (5)

Answer 2

1 Fertilized egg grows–> 2 differentiates into organs (leaves, stems)—>3 juvenile phase (vegetative)—> 4 mature/adult phase (bears flowers, fruits)—> 5 senesces / dies

Question 3

development is the result of a _______

Answer 3

pre-determined program

Question 4

define pre-determined program

Answer 4

genetically controlled

Question 5

Developmental changes (such as flowering, 
dormancy induction, cold-hardening etc.) result from the \_\_\_\_\_\_ at specific time / period during the life cycle.

Answer 5

expression of specific genes

Question 6

define epigenetic changes

Answer 6

change does not occur in the basic genotype/gene make-up of plant

Question 7

define growht

Answer 7

A quantitative term – related to change in size, mass, volume

Question 8

Growth is an _______ increase in volume or size or the weight* (expanding leaves or fruits)

Answer 8

irreversible

Question 9

what does plant growth occur due to

Answer 9

cell division and cell elongation

Question 10

where does cell division take place?

Answer 10

meristems

Question 11

what growth occurs in Apical meristem

Answer 11

increase in length/height

Question 12

what growth occurs in lateral meristem

Answer 12

increase in girth (woody, dicot)

Question 13

what are the meristems of grasses known as

Answer 13

intercallery

Question 14

define differentiation

Answer 14

Change in the form and function of cells that are produced by cell division (specialization of structure and function)

Question 15

define de-differentiation

Answer 15

mature cells from a leaf section can be stimulated to reacquire an ability to divide to produce mass of callus cells

Question 16

define redifferentiation

Answer 16

callus cells then differentiate, i.e. produce shoots and roots in the presence of nutrients and appropriate balance of HORMONES
(auxins and cytokinins)

Question 17

what does tissue culture medium contain?

Answer 17

carbohydrates, salts, vitamins, hormones (auxins and cytokinins), and AGAR, a gel-like support – sterile environment

Question 18

what is tissue culture in the horticulture industry used for

Answer 18

rapid multiplication of disease-free, clonal plants

Question 19

development =

Answer 19

growth + differentiation

Question 20

what are three ways growth can be measured

Answer 20

fresh weight, dry weight, and relative growth rate

Question 21

define fresh weight

Answer 21

Weight of a freshly harvested plant / plant part– increase in the FW with time gives a measure of growth

Question 22

why is fresh weight not always accurate

Answer 22

diurnal and seasonal fluctuations

Question 23

define dry weight

Answer 23

measure of the dry matter accumulated in

the plant tissue (everything but water)

Question 24

is dry or fresh weight used more often>

Answer 24

dry

Question 25

define relative growth rate

Answer 25

relative measure of growth rate

Question 26

define senescence

Answer 26

final stage of the development of cells, tissues, and organs, the consequence of an aging process

Question 27

describe senescence seasonally

Answer 27

leaf fall in deciduous shrubs/trees – N is mobilized from these senescing leaves & stored as storage proteins in the bark (Bark Storage Proteins) that are used for new growth in the spring

Question 28

what is a form of programmed cell death

Answer 28

senescence

Question 29

what does PCD stand for

Answer 29

programmed cell death

Question 30

Plants constantly respond to their environment by sensing cues or SIGNALS such as ________ which all modulate various developmental processes

Answer 30

light, temperature, gravity, soil moisture

Question 31

in order for a signal to be effective it must be _____ by the cell

Answer 31

perceived

Question 32

after a signal is perceived it must be _____ to some change in the cellular environment / chemistry

Answer 32

transduced (converted)

Question 33

after transduction

Answer 33

there is a response

Question 34

what involves second messangers

Answer 34

transduction

Question 35

what is a common second messanger

Answer 35

Ca 2+

Question 36

______ leaf of bean plant is a SIMPLE leaf while the ______ leaves are COMPOUND

Answer 36

Juvenile and adult

Question 37

Hormones Can affect physiological processes at exceedingly _____ concentration (ppm, micromolar)

Answer 37

low

Question 38

what are the 3 effects of pgrs and hormones depend on

Answer 38

1. Dosage and Developmental stage 2. environmental conditions and the nutritional status of the plant 3. he responsiveness of the target cell / organ

Question 39

define pgr

Answer 39

synthetic compounds that mimic hormones

Question 40

define plant hormone

Answer 40

•Naturally occurring Organic substances

Question 41

what are the 5 major classes of plant hormones

Answer 41

Auxins, Gibberellins, Cytokinins, Abscisic acid, Ethylene