Plant Growth And Development

Question 1

Root anatomy

Answer 1

Root hairs
Areas of cell differentiation 
Area of cell elongation 
Area of cell division 
Root cap

Question 2

Casparian strip

Answer 2

Specially differentiated endodermal cells with special cell walls. Water proofing the central cylinder and its water conductive properties.

Question 3

Root apical meristem: a self-sustainable population of cell initials giving rise to rest of root cells

Answer 3

Apical meristem

Primary meristems: protoderm, ground meristem, procambium

Primary tissues: epidermis, ground tissue, primary xylem and phloem

Question 4

Lateral root differentiate?

Answer 4

Lateral root initiation:auxin perception, cell repectification, asymmetric cell division

LRP development: cell division and differentiatio, primordium optimisation

LR emergence: cell division and expansion, establishment of LR meristem

Question 5

Root system architecture

Answer 5

Plastic allows a plant to adapt to it’s environment. Resource foraging.

Question 6

Symbiotic roots

Answer 6

Mycorrhizae where symbiotic relationship forms between plant and fungus.

Fungus provides pathogen protection and increases surface are for nutrient absorption.

Plant gives sugar and amino acids as food for fungus.

Question 7

Plant hormones

Answer 7

Environmental input and programmes development lead to hormone synthesis. Leads to transport site of action leads to receptor which leads to a signal transduction and response and threshold leads to response termination.

Question 8

Bio synthetic pathways

Answer 8

Amino acids: ethylene, IAA

isoprepenoid pthway: strigalactones, gibberelins, cytokins
Lipids: jasmonic acid

Question 9

ABA

Answer 9

Induces ethylene

Mostly moves via phloem but some root-originating ABA can move via xylem

Establishment and maintenance of dormancy on seed buds.
Regulation of water stress via regulation of stomatal opening and transpiration
Promotes root growth and inhibits shoot growth when water potential low

Question 10

Locations of hormones

Answer 10

Nucleus: Jasonate, gibberlenin, iaa
Cyctosol: : absisic acid

Near endoplasmic reticulum: cytokinin, ethylene

Question 11

Photometry

Answer 11

Basic unit of flowering plant shoot. Leaf, axillary meristem, internode