Embryogenesis (Lec)

Question 1

The diploid, spore-producing phase in the life cycle of a plant, algae, or fungi

Answer 1

Sporophyte

Question 2

Stages of Sporophytic Development

Answer 2

• Embryogenesis
• Vegetative Development
• Reproductive Development

Question 3

Formation of the embryo

Answer 3

Embryogenesis

Question 4

Formation of the overall shape, structure, and organization

Answer 4

Morphogenesis

Question 5

Formation of the organs

Answer 5

Organogenesis

Question 6

Formation of the tissues from undifferentiated cells

Answer 6

Histogenesis

Question 7

Stages of embryogenesis in Arabidopsis thaliana

Answer 7

• Zygote stage
• Globular stage
• Heart stage
• Torpedo stage
• Mature stage

Question 8

Stage where asymmetric division happens creating the apical cell (forms embryo) and basal cell (forms suspensor)

Answer 8

Zygote Stage

Question 9

Anchors the embryo to the embryonic sac wall and produces and directs auxin (IAA) toward the embryo to regulate pattern formation and axis development (apical–basal polarity)

Answer 9

Suspensor

Question 10

A cell at the tip of the suspensor that gives rise to RAM and root cap

Answer 10

Hypophysis

Question 11

Stage where radial symmetry is established and tissue layers begin to form. Initiation of protoderm, ground meristem, and procambium

Answer 11

Globular Stage

Question 12

Stage where there is the formation of two cotyledons and bilateral symmetry begins. The shoot and root meristems are also established.

Answer 12

Heart Stage

Question 13

Stage where there is further elongation of the embryo and tissue differentiation.

Answer 13

Torpedo Stage

Question 14

Stage where the embryo fully developed with visible cotyledons, hypocotyl, root, and shoot meristems.

Answer 14

Mature Stage

Question 15

Developmental zones/regions along the apical-basal axis and their derived structures

Answer 15

Apical: Cotyledons, Shoot Apical Meristem
Central: Hypocotyl (Embryonic stem)
Basal: Root Apical Meristem, Suspensor

Question 16

Developmental zones/regions along the radial axis and their derived structures

Answer 16

Procambium: Vascular Tissues (Xylem and Phloem)
Ground Tissue: Cortex and Endodermis
Protoderm: Epidermis

Question 17

Encodes acetyl-CoA carboxylase and synthesizes VLC fatty acids. Required for development of the apical region of the embryo (Cotyledons and SAM)

Answer 17

Gurke

Question 18

Mutant with no cotyledons or shoot structures making it resemble a cucumber

Answer 18

Gurke mutant (gk mutant)

Question 19

Encodes sterol C14 reductase. The enzyme is used for biosynthesis of brassinosteroids which are essential for organized cell division

Answer 19

Fackel

Question 20

Mutant with reduced or absent cotyledon and disorganized vascular tissues and poor root and shoot development

Answer 20

Fackel mutant (fk mutant)

Question 21

Encodes Auxin Response Factor (ARF), a class of transcription factors that regulates auxin distribution and auxin-responsive genes essential for the correct formation of the RAM and SAM

Answer 21

Monopteros

Question 22

Mutant only has a single cotyledon, and no root or shoot development

Answer 22

Monopteros mutant (mp mutant)

Question 23

Encodes a Guanine Nucleotide Exchange Factor (ARF-GEF) which is involved in the polarization factor of auxin transport forming the auxin gradient

Answer 23

Gnom

Question 24

Mutant with no defined root and SAM with disrupted polarization and auxin gradient. Embryo shows a swollen, globular shape with no obvious axis formation.

Answer 24

Gnom mutant

Question 25

Encodes a WOX transcription factor which is important for vascular development via influence of cell fate determination

Answer 25

Wooden Leg

Question 26

Mutant with the absence of functional vascular tissue

Answer 26

Wooden Leg mutant (WOL mutant)

Question 27

Encodes a transcription factor essential for the radial patterning of the root, more focused on the endodermis and cortex. Directly activated by SHR

Answer 27

Scarecrow

Question 28

Mutant has no defined cortex and endodermis with disrupted radial symmetry

Answer 28

Scarecrow mutant (SCR mutant)

Question 29

Encodes a transcription factor essential for the radial patterning of the root, more focused on the stele

Answer 29

Short root

Question 30

Mutant has abnormal development of the RAM

Answer 30

Short root mutant (SHR)

Question 31

Meristematic Tissues

Answer 31

- Root Apical Meristem - Shoot Apical Meristem - Intercalary Meristems - Marginal Meristems (Edges of developing organs, leaves, and petals) - Meristemoids (Gives rise to trichomes and stomata)

Question 32

Regions of Root Apical Meristem

Answer 32

- Root Cap - Quiscent Center - Meristematic Zone - Elongation Zone - Maturation Zone

Question 33

Found at the the tip of plant roots, it is a group of slowly dividing cells found in the root apical meristem (RAM). It plays a crucial role in maintaining the surrounding stem cells in an undifferentiated state

Answer 33

Quiescent Center

Question 34

Cells that contain statoliths that help detect gravity, influencing the auxin to move downwards. Found at the tip of the root cap

Answer 34

Columella

Question 35

Cell division that occurs perpendicular to the surface or axis of the plant. Vertical/Lengthwise

Answer 35

Anticlinal

Question 36

Cell division that occurs parallel to the surface or axis of the plant. Horizontal

Answer 36

Periclinal

Question 37

Divide anticlinally to create daughter cells that divide periclinally to form two files of cells that mature into lateral root cap and epidermis

Answer 37

Epidermal Lateral Root Cap Initials

Question 38

Divide anticlinally to create daughter cells that divide perclinally to form two cortical and endoedermal cell layers

Answer 38

Cortical-Endodermal Initials

Question 39

Gives rise to vascular system and pericycle

Answer 39

Stele initials

Question 40

Plant hormone that promotes shoot formation. Signals begin early in root development in the hypophysis of globular embryo

Answer 40

Cytokinin

Question 41

In this division stage the cytokinin expression is lost in the basal cell but is retained in the apical cell

Answer 41

Division of Hypophysis

Question 42

Zones of the SAM

Answer 42

- Central Zone (Slowly dividing cells, QC) - Peripheral Zone (Dense cells, lateral organs) - Rib Zone (Active division, vascular tissues)

Question 43

Encodes transcription factors in the NAC domain family establishing the adaxial-abaxial axis, basically directing the flow of auxin

Answer 43

CUC

Question 44

Mutant that has a a cup shape abnormality

Answer 44

CUC mutant

Question 45

Key regulator of stem cell fate in SAM. Increase of its levels would promote expression of genes that promote apical initial identity in cells that lie within the central zone

Answer 45

Wuschel

Question 46

Signaling peptide that binds to clv1 and clv2 limiting the activity of WUS

Answer 46

CLV3

Question 47

Inhibits microtubule formation, leading to enlargement

Answer 47

Colchicine