9.1 Transport in the Xylem of Plants

Question 1

Cohesion

Answer 1

Water bonded with water; occurs as a result of the polarity of a water molecule and its ability to form hydrogen bonds.

Question 2

Adhesion

Answer 2

Water bonding to non-water, charged molecules; occurs as a result of the polarity of a water molecule and its ability to form hydrogen bonds.

Question 3

Capillary Action

Answer 3

The tendency of a liquid in a capillary tube to rise or fall as a result of surface tension.

Question 4

Leaf - Blade

Answer 4

Flattened portion

Question 5

Leaf - Petiole

Answer 5

Stalk that attaches the blade to stem.

Question 6

Polarity

Answer 6

unequal distribution of a charge throughout a whole molecule where parts of the same molecule carry /inhibit different charges.

Question 7

Leaf Structure - Cuticle

Answer 7

Waxy, outermost layer; protects against water loss and insect invasion.

Question 8

Leaf Structure - Epidermis

Answer 8

Outermost layer if cuticle not present; lower epidermis has a thinner cuticle than upper (less exposed to sunlight and has lower temperature).

Question 9

Leaf Structure - Xylem

Answer 9

Vascular tissue; brings water to leaves.

Question 10

Leaf Structure - Phloem

Answer 10

Vascular tissue; carries the products of photosynthesis to the rest of the plant.

Question 11

Leaf Structure - Veins

Answer 11

Xylem and phloem together; veins are distributed throughout the leaf to transport raw materials and products of photosynthesis. Occurs roughly in the middle of the leaf so that they’re near all leaf cells.

Question 12

Leaf Structure - Palisade Mesophyll

Answer 12

Densely packed region of cylindrical cells, in upper portion of leaf where most light is available; cell contains large numbers of chloroplasts to carry out photosynthesis.

Question 13

Leaf Structure - Spongy Mesophyll

Answer 13

Bottom portion of leaf; loosely packed cells with few chloroplasts; contain many air spaces which provide gas exchange surfaces; located just above stomata to allow continuous channels for gas exchange.

Question 14

Leaf Structure - Stomata/Stomatal Pores

Answer 14

Occur on the bottom surface of leaves; allow oxygen and carbon dioxide exchange between leaf and surrounding environment; bottom of the leaves receive less light, so temperature lower minimising water loss from pores of the plant.

Question 15

Leaf Structure - Guard cells

Answer 15

Specialised cells which control the opening and closing of the stomata.

Question 16

Transpiration

Answer 16

The loss of water from leaves and stems of plants; inevitable consequence of gas exchange in leaves.

Question 17

Cohesion-Tension Theory of Plant Fluid Movement

Answer 17

Denotes the process of transpiration.

Question 18

Potometers

Answer 18

Devices used to estimate transpiration rates by measuring the rate of water loss/uptake.

Question 19

Osmosis

Answer 19

Net movement of water molecules across a semipermeable membrane from a region with low solute concentration to a region with high solute concentration - until equilibrium is reached.

Question 20

Environmental Factors with Effect on Transpiration Rate

Answer 20

Light; Humidity; Wind; Temperature; Soil Water; Carbon Dioxide.

Question 21

Xerophytes

Answer 21

Plants adapted to growing in deserts and other dry habitats.

Question 22

Halophytes

Answer 22

Plants adapted to grow in water with high levels of salinity (salt water).