Chapter 34

Question 1

The thin, transparent layer of wax that covers the leaf surface is a compromise between the needs to optimize ___ and to minimize ___ ___

Answer 1

The thin, transparent layer of wax that covers the leaf surface is a compromise between the needs to optimize photosynthesis and to minimize water loss

Question 2

Simple leaves

Answer 2

single blade

Question 3

compound leaves

Answer 3

having a blade divided into two or more leaflets

Question 4

Leaves are arranged on a stem in one of three ways:

Answer 4

1. alternate
2. opposite
3. whorled

Question 5

Alternate arrangement of leaf

Answer 5

On leaf at each node

Question 6

Opposite arrangement of leaf

Answer 6

two leaves on each node

Question 7

Whorled arrangement of leaf

Answer 7

three or more leaves at each node

Question 8

leaf blades may have ___ or ___ venations

Answer 8

leaf blades may have parallel or netted venations

Question 9

netted veins can be

Answer 9

pinnately netted or palmately netted

Question 10

pinnately netted

Answer 10

major veins branching off in succession along the midvein

Question 11

palmately netted

Answer 11

major veins radiating out from one point

Question 12

Most cells in the ___ and ___ epidermis of the leaf lack ___ and are relatively transparent

Answer 12

Most cells in the upper and lower epidermis of the leaf lack chloroplasts and are relatively transparent

Question 13

Epidermal cells of the leaf secrete

Answer 13

a waxy cuticle that reduces water loss from exterior walls

Question 14

many leaves are covered in ___

Answer 14

many leaves are covered in trichomes

Question 15

trichomes

Answer 15

the “hairs” that are extensions of the epidermal cells on a leaf

some help reduce water loss, secrete stinging irritants to deter herbivores or excrete excess salts

Question 16

leaf epidermis contains ___ for gas exchange

Answer 16

leaf epidermis contains stomata for gas exchange

Question 17

each stomata is flanked by two ___ cells which ___ and ___ the stomata

Answer 17

each stomata is flanked by two guard cells which open and close the stomata

Question 18

guard cells are associated with special subsidiary cells that provide a reservoir of ___ and ___

Answer 18

guard cells are associated with special subsidiary cells that provide a reservoir of water and ions

Question 19

leaf mesophyll

Answer 19

photosynthetic ground tissue of the leaf sandwiched between the upper and lower epidermis

Question 20

mesophyll cells

Answer 20

parenchyma cells packed with chloroplasts, loosely arranged. with many air spaces between them that facilitates gas exchange

Question 21

Palisade mesophyll

Answer 21

columnar cells in the upper layer

specialized for light capture

may be organized into one, two, three, or more layers

Question 22

spongy mesophyll

Answer 22

irregularly arranged cells in the lower layer

loosely packed cells allow diffusion of gases within the leaf; particularly co2

Question 23

no ___ cell is more than two or three cells away from a vein

Answer 23

no mesophyll cell is more than two or three cells away from a vein

Question 24

bundle sheath

Answer 24

one or more layers of nonvascular cells surround the larger veins and make up the bundle sheath

Question 25

bundle sheath may have bundle sheath extensions

Answer 25

support columns

extend through the mesophyll form the upper to lower epidermis

Question 26

Eudicot leaf

Answer 26

Broad, flattened blade with a petiole

netted venation

guard cells shaped like kidney beans

Question 27

monocot leaf

Answer 27

narrow blade; base of the leaf wraps around the stem

parallel venation

some have guard cells shaped like dumbbells

Question 28

leaf ___ is relatively transparent and allows light to penetrate to mesophyll

Answer 28

leaf epidermis is relatively transparent and allows light to penetrate to mesophyll

Question 29

stomata permit ___ to diffuse in, and ___ produced to diffuse out of the leaf

Answer 29

stomata permit CO2 to diffuse in, and oxygen produced to diffuse out of the leaf

Question 30

Veins supply ___ tissue with water and minerals and carry dissolved sugar produced during photosynthesis to all parts of the plant

Answer 30

Veins supply photosynthetic tissue with water and minerals and carry dissolved sugar produced during photosynthesis to all parts of the plant

Question 31

stomata are adjustable ___-usually open during the ___ when CO2 is required for photosynthesis and closed at ___

Answer 31

stomata are adjustable pores-usually open during the day when CO2 is required for photosynthesis and closed at night

Question 32

opening and closing of stomata are controlled by two ___ cells that surround each pore

Answer 32

opening and closing of stomata are controlled by two guard cells that surround each pore

Question 33

When water moves into guard cells, they become ___ and bend, producing a ___

Answer 33

When water moves into guard cells, they become turgid and bend, producing a pore

Question 34

When water leaves the guard cells, they become ___ and the ___ closes

Answer 34

When water leaves the guard cells, they become flaccid and the pore closes

Question 35

Additional factors that affect stomata

Answer 35

1. Low concentration of CO2 in the leaf induces stomata to open
2. prolonged draught, stomata remain closed
3. hormonal control, mostlu by abscisic acid
4. internal biological clock

Question 36

Guttation

Answer 36

typically occurs in low-growing plants at night, when stomata are closed but water continues to move into the roots by osmosis

Question 37

deciduous plants

Answer 37

change color and abscise leaves in autumn

Question 38

leaf abscission is initiated by

Answer 38

plant hormones