chapter 30 botany

Explain the role of the cork cambium in woody plants

In woody plants, the cork cambium is the outermost lateral meristem; it produces new cells towards the interior, which enables the plant to increase in girth. The cork cambium also produces cork cells towards the exterior, which protect the plant from physical damage while reducing water loss.

What is the function of lenticels?

In woody stems, lenticels allow internal cells to exchange gases with the outside atmosphere.

adventitious root

aboveground root that arises from a plant part other than the radicle of the plant embryo

Stem regions at which leaves are attached are called

nodes

meristem

plant region of continuous growth

Tracheids, vessel elements, sieve-tube cells, and companion cells are components of

vascular tissue

Compare a tap root system with a fibrous root system. For each type, name a plant that provides a food in the human diet. Which type of root system is found in monocots? Which type of root system is found in dicots?

A tap root system has a single main root that grows down. A fibrous root system forms a dense network of roots that is closer to the soil surface. An example of a tap root system is a carrot. Grasses such as wheat, rice, and corn are examples of fibrous root systems. Fibrous root systems are found in monocots; tap root systems are found in dicots.

Besides the age of a tree, what additional information can annual rings reveal?

Annual rings can also indicate the climate conditions that prevailed during each growing season.

Give two examples of modified stems and explain how each example benefits the plant.

Answers will vary. Rhizomes, stolons, and runners can give rise to new plants. Corms, tubers, and bulbs can also produce new plants and can store food. Tendrils help a plant to climb, while thorns discourage herbivores.

What type of meristem is found only in monocots, such as lawn grasses? Explain how this type of meristematic tissue is beneficial in lawn grasses that are mowed each week.

Lawn grasses and other monocots have an intercalary meristem, which is a region of meristematic tissue at the base of the leaf blade. This is beneficial to the plant because it can continue to grow even when the tip of the plant is removed by grazing or mowing.

Describe the roles played by stomata and guard cells. What would happen to a plant if these cells did not function correctly?

Stomata allow gases to enter and exit the plant. Guard cells regulate the opening and closing of stomata. If these cells did not function correctly, a plant could not get the carbon dioxide needed for photosynthesis, nor could it release the oxygen produced by photosynthesis.

What might happen to a root if the pericycle disappeared?

The root would not be able to produce lateral roots.

Which plant part is responsible for transporting water, minerals, and sugars to different parts of the plant? Name the two types of tissue that make up this overall tissue, and explain the role of each.

Vascular tissue transports water, minerals, and sugars throughout the plant. Vascular tissue is made up of xylem tissue and phloem tissue. Xylem tissue transports water and nutrients from the roots upward. Phloem tissue carries sugars from the sites of photosynthesis to the rest of the plant.

Compare the structure and function of xylem to that of phloem.

Xylem is made up tracheids and vessel elements, which are cells that transport water and dissolved minerals and that are dead at maturity. Phloem is made up of sieve-tube cells and companion cells, which transport carbohydrates and are alive at maturity.

shoot system

aboveground portion of the plant; consists of non-reproductive plant parts, such as leaves and stems, and reproductive parts, such as flowers and fruits

The primary growth of a plant is due to the action of the

apical meristem

Secondary growth in stems is usually seen in

dicots

orces selective uptake of minerals in the root.

endodermis

Roots that enable a plant to grow on another plant are called

epiphytic roots

Which of the following is the major site of photosynthesis?

ground tissue

root hair

hair-like structure that is an extension of epidermal cells; increases the root surface area and aids in absorption of water and minerals

Which of the following is an example of secondary growth?

increase in thickness or girth

stele

inner portion of the root containing the vascular tissue; surrounded by the e

endodermis

layer of cells in the root that forms a selective barrier between the ground tissue and the vascular tissue, allowing water and minerals to enter the root while excluding toxins and pathogens

Plant regions of continuous growth are made up of

meristematic tissue

intercalary meristem

meristematic tissue located at nodes and the bases of leaf blades; found only in monocots

apical meristem

meristematic tissue located at the tips of stems and roots; enables a plant to extend in length

pericycle

outer boundary of the stele from which lateral roots can arise

Which of the following cell types forms most of the inside of a plant?

parenchyma cells

ground tissue

plant tissue involved in photosynthesis; provides support, and stores water and sugars

root cap

protective cells covering the tip of the growing root

dermal tissue

protective plant tissue covering the outermost part of the plant; controls gas exchange

vascular stele

strands of root tissue made up of xylem and phloem

vascular bundle

strands of stem tissue made up of xylem and phloem

meristematic tissue

tissue containing cells that constantly divide; contributes to plant growth

vascular tissue

tissue made up of xylem and phloem that transports food and water throughout the plant

fibrous root system

type of root system in which the roots arise from the base of the stem in a cluster, forming a dense network of roots; found in monocots

tap root system

type of root system with a main root that grows vertically with few lateral roots; found in dicots

Casparian strip

waxy coating that forces water to cross endodermal plasma membranes before entering the vascular cylinder, instead of moving between endodermal cells

Newly-formed root cells begin to form different cell types in the

zone of maturation