Module 5 - Types of Plant Tissues

These tissues are composed of only 1 type of cell

Simple tissues

These tissues are composed of several types of cells

Complex tissues

These types of plants have specialized tissues for transporting water, nutrients, and food

Vascular Plants

What are specialized tissues for transporting water, nutrients, and food?

vascular tissues

These types of plants lack vascular tissues

Nonvascular plants

3 Types of Tissue Systems in Vascular Plants

- Dermal tissue system

- Vascular tissue system

- Ground tissue system

The ______ tissue system is the outer protective covering of a plant

dermal

Dermal tissues begin as ____ cells

parenchyma cells

This tissue system begins as parenchyma cells that become specialized to protect the plant from physical damage

dermal

In 1st year of growth, plants have how many layers of dermal tissue?

1

The layer of dermal tissue of plants in their first year of growth

epidermis

____ constitues the dermal tissue system

epidermis

Most epidermal cells are arranged ___

compactly

The specific arrangement of epidermal cells provides ____ to the plants

protection

The walls of the epidermal cells are covered with

cuticle

Cuticle in epidermal walls consists of

cutin and wax

The cutin and wax in epidermal cells do what?

Limit water loss because of the hydrophobic nature of lipids

Dermal tissue helps control what?

The exchange of gases

They regulate the stomata and control the movement of gases

guard cells

It consists of a pore and 2 guard cells

Stoma

In plants, ~97-99% of the water taken in by the roots is ____

released into the air

Process of losing water vapor from plants

transpiration

Water is released from leaves as ____

water vapor

Which of the following would have the least amount of transpiration?

a. Low ambient CO2 levels

b. Humid weather conditions

c. Long dryness and drought

c.

because:

Low ambient CO₂ levels: plants open their stomata more to take in CO₂ for photosynthesis -> increases transpiration

Humidity: the air is already saturated with water vapor = very little evaporation from leaves occurs -> reduces transpiration

Drought → plants often close stomata to conserve water -> plants actively stop transpiration

What process simultaneously occurs and is inextricably bound with transpiration?

Admitting CO2 for photosynthesis

Plants have not developed a structure that is both favorable to the entrance of ___ and unfavorable to the loss of ___

CO2, water

Dermal cells can become modified through the production of hair-like extensions called

trichomes

These modified epidermal cells act as a protective barrier against natural hazards

trichomes

Trichomes have ___ that deters herbivores and insects

resin

Functions of trichomes

- protective barrier against hazards

- defense mechanisms

Resin in trichomes is composed of this chemical

cannabinoids

It is a continuous tissue system that conducts water, minerals, and food

Vascular Tissues

2 complex types of vascular tissues

xylem and phloem

Water conducting tissues

Xylem

Function of xylem: brings ___ from the ____ to the rest of the plant

water, roots

The principal conducting cells of the xylem

tracheary elements: tracheids and vessels

These are water-conducting cells that are dead at maturity

tracheids and vessels

Less specialized water-conducting cell

tracheid

These water-conducting cells are less efficient but more resistant to air bubbles

Tracheids

Longer, thinner, tapered cells that overlap and align to move water through pits

Tracheids

Water flowing from tracheid to tracheid must pass through ___

pits

The xylem of most flowering plants and a few gymnosperms has another type of water-conducting cells called

vessels

Water-conducting cell that is generally wider, shorter, and less tapered

vessel

This water-conducting cell transports water and minerals more rapidly

vessels

They are more efficient conductors of water, but are less safe

vessels

Vessels are more vulnerable to ___ due to their open systems/wide pipers

embolism or air bubbles

Here, water travels relatively unimpeded

vessels

In water conducting cells, only cell walls are left (TRUE OR FALSE)

TRUE

Food-conducting tissues

Phloem

Phloem transports organic compounds (like sugars) from ___ to the rest of the plant

leaves (sites of photosynthesis)

What other substances are transported by the phloem?

amino acids, lipids, micronutrients, hormones, proteins, and RNAs

The principal conducting cells of the phloem

sieve elements with sieve cells (gymnosperms) and sieve tube elements (angiosperms)

Sieve tube elements contain ___, which are cell walls with membrane-line pores

sieve plates

____ are cell walls with membrane-line pores found in sieve tube elements

sieve plates

At maturity, the sieve tube element has no ___, so they depend on something else for maintenance

nucleus

At maturity, the sieve tube element depends on a ____ for maintenance

companion cells

Sieve tube elements and companion cells are connected by

plasmodesmata

Consists of all the tissues other than the vascular and dermal tissue systems

Ground tissues

This tissue system includes the 3 simple tissues (parenchyma, collenchyma, and schlerenchyma)

Ground tissues

Function of ground tissues

Carry out photosynthesis and store nutrients

Why can ground tissues conduct photosynthesis?

because they contain specialized parenchyma cells, specifically chlorenchyma, which possess chloroplasts