Chapter 30 - Plant Form and Physiology

Question 1

What are the Plant Organ Systems?

Answer 1

Shoot system and root system

Question 2

Shoot System

Answer 2

• Vegetative (non-reproductive) parts of a plant, such as the leaves of the stems
• Reproductive parts of the plant, which include flowers and fruit

Question 3

Root System

Answer 3

Supports the plant and absorbs water and minerals
- usually underground

Question 4

Epidermis

Answer 4

On above ground organs (leaves and stems) involved with gas exchange. On underground organs (roots) involved with water and ion uptake

Question 5

Vascular Tissues

Answer 5

Xylem - carries water and ions from the roots to stems and leaves
Phloem - carries dissolved sugars from the leaves to parts of the plant

Question 6

Ground Tissues

Answer 6

metabolism, storage, and support activities
- leaf (called mesophyll) - uses the enrgy in sunlight to synthesize sugars in a process known as photosynthesis
- stem (called pith and cortex) - supports cells to hold the young plant upright
- root (called cortex) - stores energy rich carbohydrates

Question 7

Nodes

Answer 7

points of attachment for leaves, aerial roots and flowers

Question 8

Internodes

Answer 8

regions between two nodes

Question 9

Petiole

Answer 9

stalk that extends from the stem to the base of the leaf

Question 10

Axillary Bud

Answer 10

usually found in the axil (area between the base of the leaf and the stem) where it can give rise to a branch or flower

Question 11

Apical Bud

Answer 11

The apex (tip) of the shoot contains apical meristem

Question 12

Parenchyma

Answer 12

Undifferentiated cell with potential to become other cell types
- contains organelles, thin primary cell wall
- makes up the central pith and peripheral cortex

Question 13

Collenchyma

Answer 13

similar to parenchyma cell, but with thickened cell walls. Provides support.

Question 14

Sclerenchyma

Answer 14

contain secondary cells in addiction to primary cell wall. Provides more support and strength to cells, as well as xylem and phloem
- fibers: long slender cells
- sclereids: often branched, spherical shaped

Question 15

Stomata

Answer 15

Openings that allow plant to take up carbon dioxide and release oxygen and water vapor
- flanked by two guard cells that regulate opening and closing

Question 16

Tap root systems

Answer 16

have a main root that grows down

Question 17

Fibrous root system

Answer 17

consist of many small roots

Question 18

Root epidermis

Answer 18

outermost single layer of cells that: protects from diseases and absorbs water and nutrients

Question 19

Root hairs

Answer 19

tubular extensions of epidermal cells
- increase surface area of root, better water/nutrient absorption

Question 20

Root Growth

Answer 20

a longitudinal view of the root reveals the zones of cell division, elongation, and maturation

Question 21

In typical dicots…

Answer 21

the vascular tissue forms an x shape in the center of the root

Question 22

In typical monocots…

Answer 22

the phloem cells and the larger xylem cells form a characteristic ring around the central pith

Question 23

Lamina

Answer 23

leaf blade - widest part of leaf

Question 24

Leaves attachment

Answer 24

• some leaves are attached to the plant stem by petiole
• leaves that are directly attached to the plant stem are called sessile leaves

Question 25

Leaves structure: epidermis

Answer 25

on top (adaxial) and bottom (abaxial) of leaf, usually one cell layer thick

Question 26

Palisade Mesophyll

Answer 26

upper layer of photosynthetic cells, just below upper epidermis

Question 27

Spongy Mesophyll

Answer 27

lower layer of photosynthetic cells, below the palisade layer

Question 28

Carnivorous plants

Answer 28

Insects are digested by bacteria. The plant then absorbs the smaller molecules

Question 29

Water potential

Answer 29

Plants use the potential energy in water to move water and solutes from one part of the plant to another
- influenced by solute consentration, pressure, gravity, and matrix effects

Question 30

What does the “system” refer to?

Answer 30

soil, root, stem, leaf, or atmosphere water added up

Question 31

Solute potential

Answer 31

Plant cells can metobolically manipulate by adding or removing solute molecules, therefore they have control over total water

Question 32

When total water potential is lower outside of cells…

Answer 32

water moves out of the cells and the plant wilts (flaccid cells)

Question 33

When the total water potential is higher outside the cell…

Answer 33

water moves into the cells, resulting in tumor pressure and keeping the plant erect (turgid cells)

Question 34

Transpiration

Answer 34

the main deriver of water movement in the xylem
- caused by an evaporation of water at the leaf

Question 35

Regulation of transpiration

Answer 35

Due to waxy cuticle, loss of water is prevented. Opening and closing of stomata regulates transpiration

Question 36

Cohesion Tension Theory

Answer 36

Evaporation from the mesophyll cells produces a negative water potential gradient. Causes water to move upwards from the roots through the xylem (pulled by tension)
- passive process, no atp

Question 37

Phloem Sap

Answer 37

travels through perforations called sieve tube plates

Question 38

Sucralose transport

Answer 38

it is actively transported from source cells into companion cells and then to sieve tube elements
- reduces water potential, which causes water to enter the phloem from the xylem. Resulting in positive pressure forces

Question 39

Photomorphogenesis

Answer 39

growth and development of plants in response to light. It allows plants to optimize their use of light and space

Question 40

Photoperiodism

Answer 40

the ability to use light to track time. Plants can tell time of day and year by sensing and using various wavelengths of sunlight

Question 41

Photoptrophism

Answer 41

directional response that allows plants to grow towards or away from light

Question 42

First line of defense

Answer 42

intact and impenetrable barrier. Bark and waxy cuticle can protect against predators
- other modifications include thorns or spines