Biology Exam 3

______ is the most fundamental unit of life

cell

What are the 3 basic organs of plants

roots, stems, and leaves

What systems do the 3 basic organs of plants form

root systems and shoot systems

T or F: vascular plants only rely on root systems for survivial

False: they rely on both root and shoot systems

T or F: roots are photosynthetic

False: almost never

What organ anchors a vascular plant in the soil, absorbs minerals and water, and often store carbohydrates and other reserves

roots

What is the first root and the first organ present in a plant

primary root

What later forms from the primary root

lateral roots

Tall, erect plants with large shoot masses generally have ____________

taproot system

What does a taproot system consist of

one main vertical root known as the taproot

Where does the taproot develop from

primary root

In taproot systems where does absoprtion largely occur

at the tips of lateral roots

What are the advantages of a taproot

taller growth

What is another specialization for taproots besides growth

food storage

What are small vascular plants anchored by

fibrous root systems

T or F: most monocots have fiborous root systems

True

What happens to the primary root in fibrous root systems

it dies and does not form a taproot

Instead of a taproot system what do what do small vascular plants develop

small roots that emerge from the stem

What are fiborous root systems helpful in preventing

soil erosion

What are root hairs

thin, finger-like extensions of root epidermal cells

root hairs increase the _______ of the root greatly

surface area

T or F: most root systems form mycorrhizal associations

TrueW

What are mycorrhizal associations with roots

symbiotic interactions with soil fungi to increase a plant’s ability to absorb minerals

What type of roots are described by the following characteristics

• apart of the tallest trees in the tropics

• shallow root systems

• give architectual support to the trunks of trees

Buttress roots

What type of roots are described by the following characteristics

• roots of corn

• support tall top-heavy plants

prop roots

What type of roots are described by the following characteristics

• store food and water in roots

• beet plants

storage roots

What type of roots are described by the following characteristics

• also known as air roots

• produced by trees such as mangroves

• project above the water’s surface at low tide to enable to root system to obtain oxygen

pneumatophores

What type of roots are described by the following characteristics

• Grow towards the ground and wrap around objects

  • shoots grow upwards and shade out the host tree and kill it

strangling airel roots

What type of plant organ bears leaves and buds

Steam

What is the chief function of stems

elongate and orient the shoot in a way that maximizes photosynthesis by the leaves

Besides elongate and orienting the shoot what is another function of stems

elevate reproductive structures to facilitate the dispersal of pollen and fruit

T or F: green stems can form a limited amount of photosynthesis

True

Each system consists of an altering system of ________ and _________

nodes, internodes

What are nodes

the points at which leaves are attached

What are internodes

the stem segments between nodes

Where is most of the growth of a young shoot concentrated

near the apical bud

What is found in the upper angle (axil) formed by each leaf and steam

axillary bud

What can an axillary bud potenitally form

lateral branch or even a thorn or a flower

What type of stem is described by the following characteristics

• a horizontal shoot that grows just below the surface.

• Vertical shoots emerge from axillary buds on this stem

Rhizomes

What type of stem is described by the following characteristics

• horizontal shoots that grow along the surface

• found in strawberries

• enable a plant to reproduce asexually as plantlets grow from axillary buds along each runner

stolons

What type of stem is described by the following characteristics

• found on potatoes

• enlarged ends of rhizomes or stolons specialized for storing food

tubers

In most vascular plants what organ is the main photosynthetic organ

leaf

Besides intercepting light what are some other functions of leaves

exchange gas with the atmosphere, dissipate heat, and defend themselves from herbivores and pathogens

In general what does a leaf consist of

a flattened blade and a stalk

What is the stalk of a leaf that joins the leaf to a node of the stem known as

petiole

T or F: grasses and many other monocots lack petioles

True

T or F: Monocots usually have a branched network of veins arising from a major vein that runs down the center of the blade

False: this is describing Eudicots

T or F: Most eudicots have parallel major veins of equal diameter that run the length of the balde

False: this is describing monoctos

When identifying angiosperms according to structure what do taxonomists rely on

mainly floral morphology as well as variations in leaf morphology

What type of leaf is described by the following characteristics

• has a single undivided blade and some leaves are deeply lobed

Simple leafW

What type of leaf is described by the following characteristics

• the blade consists of multiple leaflets.

• A leaflet had no axillary bud at its base.

Compound leaf

What type of leaf adaptation is described by the following characteristics

• modified leaves that offers support.

  • Sometimes modified stems

• Forms a coil to bring the plant closer to support

tendrils

What type of leaf adaptation is described by the following characteristics

• bulbs such as a cut onion have a short underground stem and modified leaves that store food

Storage leaves

What type of leaf adaptation is described by the following characteristics

• The leaves of some succulents produce adventitous plantlets which fall off the leaf and take root in the soil

reproductive leaves

What are the three fundamental tissue types that make up the organs of vascular plants

dermal, vascular, and ground tissues

what is the purpose of dermal tissue

serves at the outer protective covering of the plant.

what is the dermal tissue known as in nonwoddy plants

epidermis

What is the cuticle and what is its function

a waxy epidermal coating in leaves and plant to help prevent water loss

In woody plants what is the periderm

protective tissue found in older regions of stems and roots

What are guard cells

specialized epidermal cells found in shootsW

What is the function of guard cells

involved in gaseous exchange

What are trichomes

specialized epidermal cells found in shoots

What are the fucntions of trichomes

either reduce water loss and reflect excess light or defend again insects

What are the 2 major functions of vascular tissue

facilitate transport of materials through the plant and to provide mechanical support

What are the 2 types of vascular tissue

xylem and phloem

What is the function of xylem tissue

conduct water and dissolved minerals upward from roots into shoot

What is the function of phloem tissue

transport sugars from where they are made to where they are needed or stored

What is the vascular tissue of a root or stem called

the stele

T or F: the arrangement of the stele is the same for each species and organs

False: the arrangement of the stele varies depending on the species and organ

What does the root stele consists of in angiosperms

solid central vascular cylinder of xylem and phloem

What does the stele of stems and leaves consist of in angiosperms

vascular bundles which are separate strands containing xylem and phloem

Ground tissue that is internal to the vascular tissue is known as

pith

ground tissue that is external to the vascular tissue is called

cortex

T or F: plant cells undergo cell differentiation

True

What type of plant cell is described by the following characteristics

• have primary cell walls that are thin and flexible and most lack secondary cell walls

• When mature these cells generally have a large central vacuole

• perform most of the metabolic functions of the plant, synthesizing and storing various organic products.

  • Photosynthesis occurs within the chloroplast of these cells

• Some of these cells in stems and roots have colorless plastids called amyloplasts that store starch.

• The fleshy tissue of many fruits is composed mainly of these cells

Parenchyma cells

What type of plant cell is described by the following characteristics

• Grouped in strands

• help support young parts of the plant shoot.

• Generally elongated cells that have thicker primary walls compared to parenchyma cells

  • Wall are unevenly thickened though

• Young stems and petioles often have strands of these cells just below their epidermis.

• Provide flexible support without restraining growth.

• At maturity these cells are living and flexible, elongating with the stems and leaves they support

Collenchyma cells

What type of plant cell is described by the following characteristics

• Also function as supporting elements in the plant but are much more rigid than collenchyma cells.

• The secondary cell wall, produced after cell elongation has ceased, is thick and contains large amounts of lignin (accounts for more than a quarter of the dry mass of wood)

• Mature cells cannot elongate and occur in regions of the plant that have stopped growing in length

• many are dead at functional maturity but they produce secondary walls before the protoplast (the living part of the cell) dies.

  • The rigid walls remain as a skeleton that support the plant sometimes for hundreds of years

Sclerenchyma cells

T or F: ligin is present in byrophytes

False: all plants but not byrophytes

What are the 2 types of sclernchyma cells specilized entirely for support

sclereids and fibers

What sclerenchyma cell is described by the following traits

• boxier than the other, and irregular in shape. thick, lignified secondary walls.

sclereids

What sclerenchyma cell is described by the following traits

• grouped in strands, long, slender, and tapered

fibers

What are the 2 types of water-conducting cells

tracheids and vessel elements

What are the strucutral aspects of tracheids and vessel elements

tubular, elongated cells that are dead and lignified at functional maturity

What are tracheids found

xylem of all vascular plants

What types of plants have vessel elements

most angiosperms and some gymnosperms and seedless vascular plants

What occurs when the living cellular contents of tracheids or vessel elements disintegrate

the cell’s thickened walls remain behind, forming a nonliving conduit through which water can flow.

What occurs with the secondary walls of tracheids and vessel elements

they are interrupted by pits (thinner regions where only primary walls are present).

What water conducting cell is described by the following characteristics

• long thin cells with tapered ends

• water moves from one cell to cell mainly through pits where it does not have to cross thick secondary walls

tracheids

What water conducting cell is described by the following charactersitics

• wider, shorter, thinner walled, and less tapered.

• Aligened end to end, forming long pipes known as vessels

• The end walls have perforation plate that enable water to flow freely through the vessels

vessel elements

What type of plant cell is described by the following characteristics

• alive at functional maturity

• consists of sieve cells and sieve-tube elements

sugar-conducting cells of the phloem

How are sugars and other organic nutrients transported in seedless vascular plants and gymnosperms

through long, narrow cells called sieve cells

How are sugars and other organic nutreints transported in the phloem of angiosperms

through sieve tubes, which consist of chains of cells that are called sieve-tube elements

Though alive sieve-tube elements __________________

lack a nucleus, ribosomes, a distinct vacuole, and cytoskeleton elements.

Since there are less cell contents in sieve-tube elements what does in enable

nutreints to pass more easily through the cell

What are the end walls between sieve-tube elements called

sieve platesW

What are the functions of sieve plates

they have pores that facilitate the flow of fluid from cell to cell along the sieve tube

What is the nonconducting cell along side each sieve-tube element called

companion cell

What cellular contents are present in the companion cell

nucelus and ribosomes

What is the major difference between plants and most animals

plant growth is not limited to an embryonic or juvenille period.

What is the type of growth characteristic called in plants that occurs throughout their life

indeterminate growth