2 ... 11 - Development, tissues, and cell types

Question 1

Define development

Answer 1

series of events that progressively form an organisms body involving three overlapping processes:

1. growth
2. morphogenesis
3. differentiation

Question 2

Define growth

Answer 2

an irreversible increase in size, accomplished by cell division and cell expansion.

Question 3

Define morphogenesis.

Answer 3

the shape or form that the organism assumes

Question 4

Define differentiation.

Answer 4

process of cell specialization from an unspecified form

Question 5

How do we know what we know about plant/embryo development?

Answer 5

1. observation
2. physical manipulation
3. mutation
4. molecular tools and markers

Question 6

Give an example of physical manipulation.

Answer 6

damaging cells and observing the effect on growth/dev

Question 7

Molecular methods can be used to…

Answer 7

• clone/determine gene function.
• detect expression of gene
• generate transgenic reporter lines (living tissue)

Question 8

Every organ has three tissue types. What are they?

Answer 8

1. dermal
2. ground
3. vascular

Question 9

Define dermal tissue and describe function.

Answer 9

outer covering.

• controls gas/water movement in/out of plant
• protection against elements
• anchor, increase soil surface area contact

Question 10

Types of dermal tissue.

Answer 10

Epidermis, periderm

Question 11

Define epidermis.

Answer 11

outermost layer, composed of single layer of parenchyma cells (primary growth)

Question 12

Define periderm.

Answer 12

many layers thick, found on woody plants… replaces epidermis (secondary growth)

Question 13

Epidermal cell types

Answer 13

stomata, trichomes, root hairs

Question 14

Periderm cell types

Answer 14

cork, parenchyma

Question 15

Ground tissue cell types

Answer 15

parenchyma, collenchyma, sclerenchyma

Question 16

Describe parenchyma

Answer 16

main component of ground tissue between dermal and vascular tissue - found throughout plant, perform important processes like photosynthesis (main site) and food storage. thin cell wall, large vacuole

Question 17

Describe collenchyma

Answer 17

structural support in herbaceous plants, found just under stem epidermis and along leaf veins. thick walls… only function while alive and mature.

Question 18

Describe sclerenchyma

Answer 18

hard structural support in woody plants… may be dead/alive and still active.\

ex. wood

Question 19

Sclerenchyma cell types

Answer 19

fibers, sclereids

Question 20

Define fibers

Answer 20

long thin cells found in strands or bundles, functioning in support

Question 21

Define sclereids

Answer 21

variable shape, short and branched

Question 22

Vascular tissue function?

Answer 22

Transport system for water, nutrients, etc…

xylem, phloem

Question 23

Xylem functions?

Answer 23

transports water/minerals from roots to shoots.

mechanical support from thick cell walls

Question 24

Define tracheids

Answer 24

associated with xylem; long dead cells with tapered ends, conducts water

Question 25

Define vessel members.

Answer 25

associated with xylem; stacked, dead cylindrical cells (in angiosperms), conducts water

Question 26

Are xylem cells dead or alive at maturity?

Answer 26

Dead… thick cell walls, lack organelles and nuclei

Question 27

Phloem functions?

Answer 27

transports metabolites (sugars) and signals (hormones)

Question 28

Define sieve tube elements

Answer 28

associated with phloem; food conductive cells joined end to end… lack most organelles, no nucleus

Question 29

Define companion cells

Answer 29

associated with phloem; specialized parenchyma cells that carry out metabolic functions of sieve tube element… delivers informational molecules and ATP

Question 30

Vascular bundles consist of?

Answer 30

Xylem and phloem

Question 31

Are phloem cells dead or alive at maturity?

Answer 31

Alive… generally lack nucleus