LEAF

Question 1

other plant organ that, along with stems, constitutes the shoot of the plant body. Its principal function is to act as the main site of photosynthesis in a plant.

Answer 1

leaf

Question 2

The leaf consists of a flattened laminar portion called the

Answer 2

blade

Question 3

The leaf consists of a stalk and which attaches the blade to the stem

Answer 3

petiole

Question 4

If the blade is attached directly to the stem, the leaf is described as

Answer 4

sessile

Question 5

Leaves arise from an apical or lateral bud that is often protected by

Answer 5

bud scales

Question 6

are small leaf-like structures which develop in pairs on each side of the leaf during the growing season

Answer 6

Stipules

Question 7

In monocots, the blades are usually narrow whose base, wholly or partly encloses the stem

Answer 7

sheath

Question 8

Between the blade and the sheath, some monocot plants have appendages such as

Answer 8

auricles and ligules

Question 9

persistent meristem at the base of the leaf that allows it to grow indefinitely in monocots

Answer 9

true

Question 10

The most common shapes

Answer 10

linear (thin), lanceolate (like a spear), ovate (oval) and cordate (heart-shaped).

Question 11

lined with the veins; the middle portion of the blade usually has a prominent central vein

Answer 11

blade or lamina

Question 12

prominent central vein, while smaller veins radiate from this

Answer 12

midrib

Question 13

veins are arranged differently in monocots and dicots, explain

Answer 13

Dicots display netted venation while monocots usually have parallel venation.

Question 14

edge of the blade is called

Answer 14

margin

Question 15

margin types

Answer 15

toothed, lobed or entire.

Question 16

leaf tip

Answer 16

apex

Question 17

part near the petiole is called

Answer 17

leaf base

Question 18

There are two types of leaves

Answer 18

There are two types of leaves

Question 19

a single blade or lamina and may have any of the above characteristics
They may be deeply lobed.

Answer 19

simple leaf

Question 20

is composed of two or more separate leaflets.

Answer 20

compound leaf

Question 21

There are two basic kinds of compound leaves:

Answer 21

There are two basic kinds of compound leaves:

Question 22

the leaflets occur in a linear sequence lined up along both sides of a central axis

Answer 22

pinnately compound leaf

Question 23

central axis

Answer 23

rachis

Question 24

which three, five, seven or more leaflets are all attached at one point near the tip of the petiole and they radiate out from this tip.

Answer 24

palmate compound leaf

Question 25

How do you tell if a leaf is compound?

Answer 25

Look at the base of the leaf or petiole where it is attached to the stem. If there is a bud in the angle formed by the petiole and stem, like an axillary bud, then the entire structure supported by the petiole is a leaf, regardless of the number of leaflets present. All the leaflets of a compound leaf occur in the same plane. Also, some very large pinnately compound leaves sometimes resemble an entire branch. The branch will have a terminal bud, but a compound leaf won’t have a terminal branch.

Question 26

Leaf arrangement is referred to

Answer 26

phyllotaxy

Question 27

one leaf occurs at each node

Answer 27

alternate or spiral arrangement

Question 28

alternate and the leaves occur only on two rows

Answer 28

distichous

Question 29

two leaves at a node facing each other

Answer 29

opposite

Question 30

which two opposite leaves are perpendicular to the two opposite leaves below or above them

Answer 30

decussate

Question 31

arrangement has three or more leaves at one node

Answer 31

whorled

Question 32

outermost layer of cells

Answer 32

epidermis

Question 33

These epidermal cells secrete a waxy substance which forms a covering over the outer dermal cells rendering these cells impermeable to water. The waxy covering is called

Answer 33

cuticle

Question 34

There is an upper epidermis and a lower epidermis in a leaf with

Answer 34

dorsiventral

Question 35

The openings in the epidermis are called

Answer 35

stomates

Question 36

stomates which are formed between specialized epidermal cells called

Answer 36

guard cells

Question 37

are found on the undersurface of the leaves and herbaceous stems

These help reduce evaporation of water from plants or protect young shoots from herbivores.

Answer 37

trichomes

Question 38

with the exception of the vascular bundles, comprises all of the cells between the upper and lower epidermis and is usually divided into two parts.

Answer 38

mesophyll

Question 39

The cells toward the upper epidermis, which are elongated, make up the

Answer 39

palisade layer

Question 40

The zone below the palisade layer, composed of irregularly shaped cells

Answer 40

spongy layer

Question 41

are found between mesophyll cells

Answer 41

Inter-cellular air spaces

Question 42

In some monocots, there is no distinct palisade and spongy layers because the leaves are
all the parenchyma cells with chloroplast between the upper and lower epidermis comprise the mesophyll layer.

Answer 42

isobilateral

Question 43

function both as supporting and conducting tissue.

Answer 43

vascular bundles

Question 44

They are composed of two fundamental tissues:

Answer 44

xylem and phloem

Question 45

These conducting tissues are surrounded by vascular bundle sheath cells and are collectively called

Answer 45

veins