Horticulture Science - Stem Leaves Cells

A "typical" stem includes a leaf blade, petiole, node, internode, stem, axil with axillary bud, apical meristem, and leaf primordium. True/False

True

A leaf in which the blade is directly attached to the stem is called a _____ leaf

sessile

A leaf with a petiole is called a ____ leaf

petiole

A pair of cells surrounding a stoma is a _____

guard cell

A pore in the epidermis of leaves and herbaceous stems is called a ______

stoma

A strand of xylem and phloem in a leaf blade is known as a ____

vein

A thick cuticle layer can reflect excessive light where it is intense, such as in a ______

desert

All of a plant's axillary buds grow at one time. True/False

False

Only a small portion of a plant's axillary buds grow at one time. The remaining axillary buds stay dormant, serving as a reserve for growth in case the plant sustains damage from factors such as frost, fire, pruning, wind, or animals, or disease

All tissue in an herbaceous stem established by the apical meristem is called _____ tissue

primary

As the age of the plant increases, ____ is formed

bark

Axillary buds remain dormant until the plant _____ them to grow

stimulates

Bumps found on young bark that serve as breathing pores are called _____

lenticels

Chloroplast containing cells where photosynthesis takes place are located within the ____ of the leaf

middle

Chloroplasts within the spongy layer also capture some light. True/False

True

Clear stem sections between nodes are called _____

internodes

Damage to most leaves can be repaired easily. True/False

False

Dormant axillary buds serve as reserve growth in case of damage by frost, fire, pruning, wind, animals, or _____

disease

Dots or circles within a leaf scar are the ends of food and water conducting ____

bundles

Dots or circles within a leaf scar are the ends of food and water conducting bundles. These leaf scars indicate the former location of leaves on woody twigs.

Ear-like lobes representing the first stage of leaf formation are called _____ _______

leaf primordia

Epidermal hairs provide protection from _____

insects

Evergreens do not enter winter dormancy and therefore lack bud scale scars. True/False

True

Evidence of a twig transitioning into a woody stem is a color change from green to _____

brown

Examples of leaf types for plant identification include Pinnately compound, Serrate, Linear, Oblong, and ____

lobbed

Filaments of cells arising from the epidermal cells for protection are called ______ _____

epidermal hairs

Gas enters the leaf generally through openings called stomata, located on the ____ epidermis

lower

Gases that move between spongy cells include carbon dioxide, oxygen, and ____ _____

water vapor

Grass blades can repair damage to some degree because they grow from the base, also known as the _____

crown

Grass blades grow from _____ meristems

intercalary

Grasses and ground covers are plants that typically develop woody stems. True/False

False

Growth in stems occurs in the ____ _____ which encompasses the apical bud

apical meristem

Growth in stems occurs in the apical meristem which encompasses the apical bud. The apical meristem forms a dome of activity of dividing cells and is responsible for making stems grow longer and initiating the orderly arrangement of leaves on the stem.

Herbaceous stems are organized into how many areas? A. Four B. Five C. Six D. Seven

C. Six

Herbaceous stems are products of ______ growth

primary

Internodes stretch to ensure the leaf gets maximum exposure to ____

light

Leaf arrangements include Alternate, Opposite, and _____

Whorled

Leaf blades divided into smaller units in compound leaves are called _____

leaflets

Leaf blades that develop as a single unit are called ____ leaves

simple

Leaf scars may be found on evergreen stems, usually toward their base where leaves have dropped off due to normal aging process. True/False

True

Leaf types are used for plant ______

identification

Lenticels allow ____ to pass through

gases

Lenticels are described as bumps found on young bark that serve as breathing pores

Loosely packed cells that allow for gas exchange in a leaf are the _____ _____

spongy parenchyma

New stems arise from external buds located in the angle (axil) between a ____ and stem

leaf

Palisade cells "catch" light as it enters the leaf. True/False

True

Palisade cells are closely packed, elongated cells located directly below the upper epidermis. True/False

True

_____ trees are an example of plants that lack axillary buds and put their energy into one meristem

Palm

______ cells surround primary vascular tissue in roots and stems

Parenchyma

Parenchyma tissue typically makes up the pith, cortex, palisade, and _____ mesophyll

spongy

Spongy Cells are located in the lower mesophyll and are loosely packed to allow gases (carbon dioxide, oxygen, and water vapor) to move between them. Their chloroplasts also capture some light. They are also referred to as spongy parenchyma.

Photosynthesis requires chloroplasts to be supplied with light, water, and ____ _____ from the atmosphere

carbon dioxide

Plants that are herbaceous typically have a vascular cambium. True/False

False

Plants that are herbaceous lack a vascular cambium. Herbaceous stems are products of primary growth, and all their tissue is established by the apical meristem, which is why it is called primary tissue. In contrast, the vascular cambium, when present, separates the xylem and phloem and the cortex and pith, and results in the stem's ability to increase in size

Spongy cells are located in the _____ mesophyll

lower

Spongy cells are loosely packed to allow gases to move between them. True/False

True

Stomata help regulate water ____

loss

Structures that enclose the twig during winter to form a tight apical bud are called ___ _____

bud scales

Terminal bud scars are left on the stem each spring and will disclose the twig's ___

age

Terminal buds are pushed aside when ___ ____ start their growth

new leaves

Terminal buds begin to form in the ____ for dormancy

fall

The apical bud initiates the orderly arrangement of ____ on the stem

leaves

The apical bud is a stem's ______ point

growing

The apical bud is described as being __ than that of a root. A. Simpler B. Smaller C. More complex D. Less active

C. More complex

The apical bud is more complex than that of a ____

root

The apical bud makes stems grow ____

longer

The apical meristem forms a dome of activity of _______ cells

dividing

The ____ __ ________ is located at the base of each leaf primordial and is the beginning of a potential branch

axillary bud primordium

The center of a plant stem is called the ____

pith

The color change from green to brown in a woody twig indicates what? A. The twig is diseased B. Bark is being formed as the plant ages C. The twig is dormant D. The twig is dying

B. Bark is being formed as the plant ages

The cuticle layer is located on the outer surface of the upper and ____ epidermis

lower

The ______ protects the leaf blade from water loss

cuticle

The epidermis layer encloses the leaf blade on both sides, including the lower and ____ epidermis

upper

The leaf blade is thin and translucent to allow light to penetrate to the _______ cell

innermost

The location of chloroplasts in an herbaceous stem is the ______

cortex

The location of former leaves on a twig is marked by ___ _____

leaf scars

The location of stomata on the underside of the leaf helps prevent them from becoming _______

clogged

The mesophyll layer is comprised of two parts: palisade cells and _____ cells

spongy

The outer bark, also known as ____, continually flakes or peels off but is replaced within

cork

The outer layer of cells on an herbaceous plant organ, found on the bottom side of a leaf, is the ____ ______

lower epidermis

The outer layer of cells on an herbaceous plant organ, found on the top side of a leaf, is the ____ _______

upper epidermis

The parenchyma tissue of a leaf between the upper and lower epidermis is the _______

mesophyll

The ______ attaches the leaf to the stem

petiole

The petiole attaches the leaf to the stem. This structure also has the ability to rotate for exposure to the sun and is flexible, allowing it to withstand wind and rain. A leaf that has a petiole is referred to as a "petiole leaf"

The petiole rotates for exposure to the sun and is flexible for wind and ____

rain

The photosynthetic cells directly beneath the upper leaf epidermis that collect chlorophyll are called _____ _______

palisade parenchyma

The primary purpose of leaves is to capture light for ________ through the leaf blade

photosynthesis

The primordia fold over the meristem to serve as protection from the sun and ____

wind

The shoot system consists of the plant’s aerial stems, branches, and ______

leaves

The single outer boundary of cells in an herbaceous stem is the _______

epidermis

The size of the stomata opening is controlled by _____ cells

guard

The thickness of the cuticle layer is consistent across all plant types. True/False

False

The thickness of the cuticle layer varies from plant to plant. This variation can allow for adaptation to different environmental conditions. For example, in intense light environments like deserts, the cuticle helps reflect excessive light and protect the leaf blade from water loss.

The tips of developing woody twigs are often herbaceous before transitioning into woody stems. True/False

True

The vascular cambium results in the stem's ability to _____ in size

increase

The vascular cambium separates the xylem and phloem, and the cortex and ____

pith

The waxy layer on the outside of leaves, herbaceous stems, and fruit is the _____

cuticle

The waxy layer on the surface of epidermal cells that reduces water loss is the _____

cuticle

What protects the apical meristem from the sun and wind? A. Axillary buds B. Nodes C. Leaf primordia D. Internodes

C. Leaf primordia

The apical meristem forms a dome of activity of dividing cells. In either side of this dome, ear-like lobes develop, which are the first stage of leaf formation and are called leaf primordia. These primordia then fold over the meristem, and in doing so, they serve as a protection from the sun and wind

When a stem is being formed, it divides into short sections called _____

nodes

Where are chloroplast-containing cells, where photosynthesis takes place, primarily located within the leaf? A. Epidermis layer B. Cuticle C. Middle of the leaf D. Vascular bundles

C. Middle of the leaf

Which chronological record do evergreens lack due to not entering winter dormancy? A. Annual rings B. Bud scale scars C. Leaf scars D. Lenticels

B. Bud scale scars

Evergreens lack the bud scale scar's chronological record due to not entering winter dormancy. In plants that do enter winter dormancy, terminal bud scars are left on the stem each spring, and these scars disclose the twig's age. Since evergreens do not enter winter dormancy, they do not form these specific scars, and thus, lack this chronological record.

Although leaf scars may be found on evergreen stems, they are usually towards their base where leaves have dropped off as a result of the normal aging process.

Which of the following is a component of the plant's shoot system? A. Roots B. Aerial stems C. Tubers D. Rhizomes

B. Aerial stems

Which of the following is NOT one of the leaf arrangements mentioned? A. Alternate B. Opposite C. Spiral D. Whorled

C. Spiral

Which of these is NOT one of the six areas herbaceous stems are organized into? A. Cortex B. Vascular Cambium C. Pith D. Epidermis

B. Vascular Cambium

Which part of the leaf attaches the leaf to the stem and is flexible for wind and rain? A. Leaf blade B. Petiole C. Midrib D. Vein

B. Petiole

Which type of meristem allows grass blades to repair damage by growing from the base? A. Apical meristem B. Lateral meristem C. Intercalary meristem D. Vascular cambium

C. Intercalary meristem

Xylem and phloem are found within the ____ ______

vascular bundle

In herbaceous stems, the vascular bundle is one of the six organized areas, along with the epidermis, cuticle, epidermal hairs, cortex, and pith. Additionally, in a leaf blade, a vein is described as a strand of xylem and phloem.