Chapter 35: Plant Structure, Growth, and Development (Test 3)

Question 1

The Three Basic Plant Organs:___

Answer 1

Roots, Stems, and Leaves

Question 2

• Three basic organs evolved: roots, stems, and leaves
• They are organized into a ___ system and a ___ system
• Roots rely on sugar produced by photosynthesis in the shoot system, and shoots rely on water and minerals absorbed by the root system. Inderdependent!

Answer 2

root

shoot

Question 3

•Roots are multicellular organs with important functions:

–Anchoring the plant

–Absorbing minerals and water

–Storing organic nutrients

Question 4

• A ___ system consists of one main vertical root that gives rise to lateral roots, or branch roots
• In most plants, absorption of water and minerals occurs near the ___, where vast numbers of tiny root hairs increase the surface area

Answer 4

taproot

root hairs

Question 5

•A stem is an organ consisting of

–An alternating system of nodes, the points at which leaves are attached

–Internodes, the stem segments between nodes

Question 6

• An ___ is a structure that has the potential to form a lateral shoot, or branch
• An ___, or ___, is located near the shoot tip and causes elongation of a young shoot
• ___ - Inhibition of axillary bud by a apical bud.

Answer 6

axillary bud

apical bud (terminal bud)

Apical dominance

Question 7

• The leaf is the main ___ organ of most vascular plants
• Leaves generally consist of a flattened blade and a stalk called the ___, which joins the leaf to a node of the stem
• ___, the vascular tissue of leaves

Answer 7

photosynthetic

petiole

veins

Question 8

plant tissues

• Each plant organ has dermal, vascular, and ground tissues
• Each of these three categories forms a tissue system

Question 9

THE DERMAL TISSUE SYSTEM

• In nonwoody plants, the dermal tissue system consists of the ___
• A waxy coating called the ___ helps prevent water loss from the epidermis
• In woody plants, protective tissues called ___ replace the epidermis in older regions of stems and roots

Answer 9

epidermis

cuticle

periderm

Question 10

Vascular tissue system

carries out long-distance transport of materials between roots and shoots

• Xylem conveys water and dissolved minerals upward from roots into the shoots
• Phloem transports organic nutrients from where they are made to where they are needed
• The vascular tissue of a stem or root is collectively called the ___

Answer 10

stele

Question 11

Tissues that are neither dermal nor vascular are the ground tissue system

• Ground tissue internal to the vascular tissue is ___; ground tissue external to the vascular tissue is___
• Ground tissue includes cells specialized for___

Answer 11

pith

cortex

storage, photosynthesis, and support

Question 12

Plant Cells make up plant tissues

• Parenchyma cells
• Collenchyma cells
• Sclerenchyma cells
• Water-conducting cells of the xylem
• Sugar-conducting cells of the phloem

–

Question 13

Parenchyma Cells

•Mature parenchyma cella ___

Answer 13

–Have thin and flexible primary walls

–Lack secondary walls

–Are the least specialized

–Perform the most metabolic functions

–Retain the ability to divide and differentiate

Question 14

Collenchyma Cells

___

Answer 14

• Collenchyma cells are grouped in strands and help support young parts of the plant shoot
• They have thicker and uneven cell walls
• They lack secondary walls
• These cells provide flexible support without restraining growth

Question 15

Sclerenchyma Cells

___

Answer 15

• Sclerenchyma cells are rigid because of thick secondary walls strengthened with lignin (thickened woody fiber)
• They are dead at functional maturity
• There are two types:

–Sclereids are short and irregular in shape and have thick lignified secondary walls

–Fibers are long and slender and arranged in threads

Question 16

Water-Conducting Cells of the Xylem

• The two types of water-conducting cells, ___ and ___, are dead at maturity
• Tracheids are long, thin cells with tapered ends. They provide support under the tension of water transport.
• Vessel elements are wider and thinner-walled than tracheids. They are aligned end-to-end forming long micropipes.

•

Answer 16

tracheids, vessel elements

Question 17

Sugar-Conducting Cells of the Phloem

• ___ are alive at functional maturity, though they lack organelles
• Each sieve-tube element has a companion cell whose nucleus and ribosomes serve both cells

Answer 17

Sieve-tube elements

Question 18

Meristems generate cells for new organs

• A plant can grow throughout its life; this is called ___
• Some plant organs cease to grow at a certain size; this is called ___
• Annuals complete their life cycle in a year or less
• Biennials require two growing seasons
• Perennials live for many years

Answer 18

indeterminate growth

determinate growth

Question 19

• ___ are perpetually embryonic tissue and allow for indeterminate growth
• ___ are located at the tips of roots and shoots and at the axillary buds of shoots
• Apical meristems elongate shoots and roots, a process called ___

Answer 19

Meristems

Apical meristems

primary growth

Question 20

• ___ add thickness to woody plants, a process called secondary growth
• The ___ adds layers of vascular tissue called secondary xylem (wood) and secondary phloem
• The ___ produces a tough, thick covering that protects from water loss and invasion by insects and microbes.

Answer 20

Lateral meristems

vascular cambium

cork cambium

Question 21

Tissue Organization of Leaves

• The epidermis in leaves is interrupted by ___, which allow CO2 exchange between the air and the photosynthetic cells in a leaf
• Each stomatal pore is flanked by two guard cells, which regulate its opening and closing
• The ground tissue in a leaf, called ___, is sandwiched between the upper and lower epidermis
• Transpiration-Evaporative loss of water from plant

Answer 21

stomata

mesophyll

Question 22

• Below the palisade mesophyll in the upper part of the leaf is loosely arranged spongy mesophyll, where gas exchange occurs
• The vascular tissue of each leaf is continuous with the vascular tissue of the stem
• Veins are the leaf’s vascular bundles and function as the leaf’s skeleton
• Each vein in a leaf is enclosed by a protective bundle sheath

Answer 22