Plant Morphogenesis and Organogenesis

Question 1

the development of a plant’s form and structure—involves several overlapping developmental processes, including growth and cell differentiation.

Answer 1

Plant morphogenesis

Question 2

is defined as the development of organs, like roots, shoots, and flowers, either directly from an explant, or from the callus culture.

Answer 2

Organogenesis

Question 3

A plant’s ability to grow is determined by ____, as well
as a variety of factors in the plant’s environment.

Answer 3

genetics

Question 4

_____ differentiate into specific cell types, which are organized into the tissues and organ systems that make up the functional plant.

Answer 4

Precursor cells

Question 5

The levels for control of gene expression

Answer 5

1. Genome
2. Transcription
3. RNA processing and translocation
4. Translation
5. Posttranslation

Question 6

Eukaryotic gene expression can be regulated
at multiple levels.

Answer 6

(1) genomic regulation, by gene amplification,
DNA rearrangements, chromatin decondensation or
condensation, or DNA methylation;

(2) transcriptional regulation;

(3) RNA processing, and RNA turnover in the nucleus
and translocation out of the nucleus;

(4) translational control
(including binding to ER in some cases);

(5) post translational control, including mRNA turnover in the cytosol, and the folding, assembly, modification, and import of proteins into organelles.

Question 7

Plant growth and cell differentiation are under
complex ___. Plant hormones regulate _____, often in response to environmental stimuli.

Answer 7

hormonal control

gene expression

Question 8

____ enable the conversion of the shoot apical meristem into the inflorescence meristem, allowing the meristem to produce floral rather than vegetative structures.

Answer 8

Meristem identity genes

Question 9

___ are endogenous guide for plant growth and development

Answer 9

Phytohormones

Question 10

(Phytohormones)
- each of which acts at low concentrations to regulate many aspects of plant growth and development.

Answer 10

Auxin, cytokinin, the gibberellins (GAs), abscisic acid (ABA),
ethylene, the brassinosteroids (BRs), and jasmonic acid (JA),

Question 11

Apical meristems are located at the growing tips of the adult plant, and produce _____.

Shoot Apical Meristems (SAM) initiate ____ during vegetative development, and _____ and ____ during reproductive development.

Answer 11

root and shoot tissue

leaves

inflorescence (IM) and floral meristems (FM)

Question 12

Shoot apical meristem generates all above-ground organs throughout the life of plants and is known to be a meristem that provides cells for _____

Answer 12

postembryonic growth and development

Question 13

The ___ are the reproductive part of the plant.

The arrangement of flowers on the floral axis is called
____, which has two major parts called ____
which let the main axis continue to grow and ____
which terminates the main axis in a flow.

Answer 13

flowers

inflorescence

racemose
cymose

Question 14

The flower consists of four different whorls:

____, the outermost.
___, composed of petals.
___, composed of stamens.
___, composed of one or more carpels.

Answer 14

Calyx
Corolla
Androecium
Gynoecium

Question 15

Pistil develops from the

Answer 15

carpel primordia

Question 16

When flowering is initiated, the ___ begins to develop
in the center of the flower. It consists of ___ (at top),
___ and ___ (at base).

The ovary (a) of the pistil has one or more separate or ___ (b). Within the carpel are ___ (c) where ___ (d) develop.

Answer 16

pistil

stigma
style
ovary

fused carpels
locules
ovules

Question 17

Embryo sac-

Ovule development begins with meiosis in a 2n _____
mother cell (e) within the center portion of a young
ovule (____). The megaspore mother cell undergoes a ___ (meiosis) to form a ____ of 1n megaspores. Of these, usually 3 abort (f) with one megaspore (g) remaining.

Answer 17

A Female gametophyte containing egg cell

megaspore

megasporangium

double reduction/division

linear tetrad

Question 18

Embryo Sac

The nucleus of the remaining megaspore divides repeatedly (mitosis) to form the 8 haploid (1n) nuclei of
the ___ (female gametophyte, h).

The central part of the ovule is ____, ____ (i). Surrounding the embryo sac are one or two layers of cells, the ____ (j), with a small opening at the base called the ___ (k).

Answer 18

embryo sac

vegetative tissue, nucellus
integuments
micropyle

Question 19

The mature ovule within the pistil consists of the embryo sac (h) surrounded by nucellus (i) and integuments (j). It is attached to the placenta (q) by a stalk called the ____ (r).

Answer 19

funiculus

Question 20

Gametes of flowering plants are not the
direct products of meiosis. Instead
_____ are formed after two
additional mitotic cell divisions creating
a three-celled male gametophyte, the ____ and ___

Answer 20

sperm cells

pollen and pollen tube

Question 21

The early stages of fruit development are highly
active in the production of ___, which are
essential for ___ and subsequent ___

model plant:

Answer 21

sterols

rapid cell division
cell expansion

Tomato (Solanum lycopersicum L.)

Question 22

_____ is the most widely used external index of tomato maturity, and distinct changes in external color can be used to determine harvest maturity

Answer 22

Skin color

Question 23

1. The hormones that play a major role in the regulation of fruit set and in the determination of fruit size
2. At the end of the cell division phase, seeds start to produce ____ which stimulate fruit growth and
   placental expansion inside the locular cavity

Answer 23

1. Auxin, GA, and CK
2. auxin and CK,

Question 24

_____ and _____ are the primary hormones governing the fruit maturation and ripening phases

Answer 24

1. Auxin together with CK
2. ethylene together with ABA

Question 25

Based on the involvement of ___ in the ripening process, fruits can be classified as ___ or ___

Answer 25

ethylene

climacteric
non-climacteric.

Question 26

In climacteric fruits, ripening is controlled by ____

whereas ___ seems to have a stronger role during ripening of non-climacteric fruits by ____

Answer 26

ethylene in crosstalk with auxin

ABA
up-regulation of ethylene biosynthesis genes

Question 27

• A tough outer coating enclosing the cell, the cell wall
acts as a cellular “____” that controls cell
shape and allows high turgor pressures to develop.

Answer 27

exoskeleton

Question 28

Cell wall function in plants

Answer 28

• determine mechanical strength, allowing those structures to grow to great heights
• for normal water relations
• the wall determines the cell turgor pressure and cell volume
• acts as a diffusion barrier

Question 29

are formed by growing cells and are usually considered to be relatively unspecialized and similar in molecular architecture in all cell types.

Answer 29

Primary walls

Question 30

are the cell walls that form after cell growth (enlargement) has ceased. Secondary walls may become highly specialized in structure and composition, reflecting the differentiated state of the cell

Answer 30

Secondary walls

Question 31

NEW PRIMARY WALLS ARE ASSEMBLED
DURING ___

SECONDARY WALLS FORM IN SOME CELLS
AFTER ____

Answer 31

CYTOKINESIS

EXPANSION CEASES

Question 32

Plant tissues are composed of three basic cell types:

Answer 32

parenchyma,
collenchyma,
and sclerenchyma

Question 33

____ are examples of plant cells that exhibit tip growth. (B) If marks are placed on the surface of a diffuse growing cell, the distance between all the marks increases as the cell grows. Most cells in multicellular plants grow by
diffuse growth.

Answer 33

Root hairs and pollen tubes

Question 34

Wall expansion may be highly localized (as in the case of ___) or evenly distributed over the wall surface (___)

Answer 34

tip growth

diffuse growth

Question 35

Factors influence the rate of cell wall expansion.

Answer 35

Cell type and age
Hormones such as auxin and gibberellin
Environmental conditions such as light and
water availability, pH (wall loosen in acidic pH)

Question 36

PATTERNS OF CELL EXPANSION
Stress Relaxation of the Cell Wall Drives Water
Uptake and Cell Elongation

• Auxins are a group of hormones produced by the tip
  of a shoot or root (i.e. ____) that regulate plant growth
• Auxin activates a ____ in the plasma membrane which causes the secretion of ____ into the cell wall
• The resultant decrease in pH causes ___ within the cell wall to loosen (by breaking the bonds between them)
• Additionally, ___ upregulates expression of expansins, which similarly increases the elasticity of the cell wall

-With the cell wall now more flexible, an influx of
___ (to be stored in the vacuole) causes the cell
to increase in size

Answer 36

apical meristems

proton pump; H+ ions

cellulose fibres

auxin

water

Question 37

___ transports sugars and other items. In angiosperms, ____ contain the sugar solution. ____ are surrounded by various support cells.

Answer 37

Phloem

sieve-tube elements

Sieve-tube cells

Question 38

____ mainly consists of dead cells that have primary and secondary cell walls which provide support

Answer 38

Sclerenchyma

Question 39

___ cells also function in support though they are living.

Answer 39

Collenchyma

Question 40

___ cells are un-specialized cells that carry out most of a plant’s metabolism.

Parenchyma cells with chloroplasts are called ____ cells.

Answer 40

Parenchyma

chlorenchyma

Question 41

transports water and minerals through vessel elements and tracheids, which are dead at maturity and have a primary and secondary cell wall. In pits, the secondary wall is thin of missing, allowing water to flow laterally

Answer 41

Xylem