What are the characteristics of Monocots?
Monocots have one cotyledon, their veins are usually parallel,their vascular bundles are in complex arrangements, their floral parts are usually in multiples of three, and they have a shallow fibrous root system.
What are the characteristics of Dicots?
Dicots have two cotyledons, their veins are usually branched, their vascular bundles are arranged in a ring, their floral parts are usually in groups of four or five, and they have a taproot system.
Of what are roots and extension?
Roots are an extension of the epidermal cell (the cell in the outer layer of the root). Root hairs enormously increase the surface area for absorption of water and minerals.
What are the embryonic leaves called?
Embryonic leaves are cotyledons. A monocot has one seed leaf, and a eudicot has two seed leaves.
What are nearly all of our fruits and vegetables? Monocots or dicots?
Nearly all of our fruits and vegetables are dicots. Most flowering shrubs and trees are eudicots as well.
Why can roots and shoots not live without each other?
Lacking chloroplasts and living in the dark, most roots would starve without the sugar and other organic nutrients transported from the photosynthetic leaves of the shoot system. Stems and leaves depend on the water absorbed by the roots.
What attaches the leaf blade to the node on the plant stem?
Petioles attach the leaf blade to the node on the stem.
What are the points at which the leaves are attached called?
The points at which the leaves are attached are called nodes.
What are the portions of the stem between the nodes called?
The portion of the stem between the nodes are called internodes.
What are the main photosynthetic portions of a plant?
The leaves are the main photosynthetic organs in most plants, although green stems also perform photosynthesis.
What is the terminal bud?
The terminal bud is the embryonic tissue at the tip of a shoot, made up of developing leaves and a compact series of nodes and internodes. It is the underdeveloped shoot at the apex of a plant.
What is apical dominance and why is it present?
Apical dominance means that in the presence of a terminal bud, axillary buds will not grow due to a production of hormones by the terminal bud. This is an evolutionary adaptation that promotes tall growth, increasing the plant's exposure to light.
What does removing the terminal bud promote?
Removing the terminal bud stimulates the growth of the axillary buds (why pinching back houseplants makes them bushier)
What are carrots, turnips, beets, and potatoes examples of?
Carrots, turnips, beets, and potatoes are all examples of taproots.
What are arial roots?
Arial roots are roots that stick up out of the ground for gas exchange and oxygen for the roots.
What are stolons?
Stolons are horizontal stems that grow along the ground and enable a plant to reproduce asexually as plantlets form at nodes along their length. (ex: strawberries- why if unchecked, they can grow rapidly in the garden).
What are Rhizomes?
Rhizomes are horizontal stems that grow underground or near the soil surface. They store food and make new shoots.
What are potato eyes?
Potato eyes are axillary buds on the tubers that can grow when planted, allowing potatoes to be easily propagated.
What is a tendril and what does the tendril of a pea plant do?
A tendril is the modified leaf. The tendrils of a pea plant (or any plant with tendrils) helps the plant climb. Some tendrils such as in grapevines are modified stems.
What is the main part of a cactus?
The main part of a cactus is the stem, which is adapted for photosynthesis and water storage.
What does the vascular tissue, phloem transport?
Phloem transports sugars and other organic nutrients from leaves or storage tissues to other parts of the plant.
What are the three types of tissues that each plant organ has?
Each plant organ has dermal, vascular, and ground tissues that form a tissue system.
What is a tissue system?
A tissue system is a functional unit connecting all of the plant's organs. Each tissue system is continuous throughout the plant body, but the systems are arranged differently in leaves, stems, and roots.
What is the dermal tissue system?
The dermal tissue system is the plant's outer protective covering. It forms the first line of defense against any physical damage and infectious organisms. Consists of the epidermis and cuticle. All plants have dermal tissue.
What is the epidermis?
The epidermis is a single layer of tightly packed cells that often has a waxy cuticle on top.
What is the function of vascular tissue?
Vascular tissue is used for support and long distance transport between the root and shoot systems. Vascular tissue consists of xylem and phloem.
What is the ground tissue system and of what does it consist?
The ground tissue system accounts for most of the bulk in a young plant and fills the spaces between the epidermis and the vascular tissue system. Tissues neither dermal nor vascular make up the ground tissue system. The ground tissue internal to the vascular tissue is the PITH, the ground tissue external to the vascular tissue is the cortex.
What functions does the ground tissue system have?
The ground tissue system serves functions such as photosynthesis, storage, and support.
What is the purpose of guard cells?
The purpose of guard cells is to regulate the size of the stoma/the opening and closing of the stoma.
What are stomata?
Stomata are tiny pores in the epidermis of a plant that allow exchange of CO2 and O2 between the surrounding air and the photosynthetic cells inside the leaf.
Through where does most of the water vapor that is lost by plants pass?
Most of the water vapor lost by plants passes through stoma.
What is a vein?
A vein is a vascular bundle composed of xylem and phloem tissues surrounded by a protective sheath of cells.
What are the purposes of plant veins?
Plant veins are in close contact with the leaf's photosynthetic tissues, ensuring that those tissues are supplied with water and mineral nutrients from the soil and that sugars made in the leaves are transported throughout the plant. It also functions as a skeleton, reinforcing the shape of the plant.
What are the three unique structures that most plant cells have?
Most plant cells have chloroplasts the sites of photosynthesis, a central vacuole that contains fluid to help maintain turgor, and a cell wall made from the structural carbohydrate cellulose surrounding the plasma membrane.
What is the middle lemella?
The middle lemella is the sticky layer that holds primary walls together.
What is the pit?
The pit is where walls are thin, allowing migration of water between adjacent cells.
What are the most abundant type of cell in most plants?
Parenchyma cells are the most abundant type of cell in most plants.
Why are parenchyma cells thin and flexible?
Parenchyma cells are thin and flexible because they usually only consist of a primary cell wall and remain alive when mature.
What are the functions of parenchyma cells?
Parenchyma cells perform most of the metabolic functions of a plant, such as photosynthesis, aerobic respiration, and food storage. Most parenchyma cells can divide and differentiate into other types of plant cells under certain conditions, such as during the repair of an injury.
What are the functions of collenchyma cells?
Collenchyma cells provide flexible support in actively growing parts of the plant (young stems and petioles often have collenchyma cells just below their surface) Cell elongate as stems and leaves grow. Collenchyma cells only have primary walls, but they are unevenly thick due to the presence of Pectin.
What are sclerenchyma cells and what do they do?
Sclerenchyma cells are cells that have thick secondary cell walls usually strengthened with lignin. Cannot elongate because when they are mature they are dead. Form a skeleton that supports plants. Sclerenchyma cells include fiber and sclereids.
How does xylem transport water?
Xylem transports water by vessel elements and tracheids. These vessels have lignified secondary walls and hollow tubes.
What is the difference between tracheids and vessel elements?
Tracheids are long, thin hollow cells with tapered ends in the xylem that aid in transport. Vessel elements are wider than tracheids, and are also shorter and less tapered.
How does phloem transport sugar?
Phloem transports sugar by sieve-tubes that are alive at maturity. Sieve tubes loose most organels at maturity and don't have a nucleus.
How are sieve tubes divided?
Sieve tubes are divided by sieve plates on either end of the tube that contain pores to transport sugars from one tube to the next.
What are companion cells?
Companion cells are cells that load sugar into sieve tubes and transport nutrients from one cell to the next.
What are some examples of biennials?
Some examples of biennials are beets, parsley, turnips, and carrots. We usually harvest these plants in the first year so we miss seeing their flowers.
What are some examples of perennials? What is usually the cause of their death?
Trees, shrubs, and some grasses are all perennials. The main cause of the death of Perennials is infection or environmental trauma.
How is the growth in a plant made possible?
Meristems make the growth in all plants possible. Meristems consist of undifferentiated (unspecialized cells) that when conditions permit, divide into new cells.
What does primary growth enable?
Primary growth enables roots to push through the soil and allows shoots to grow upward, increasing exposure to light and CO2.
What is a root cap?
A root cap is a thimble-like protective coat that protects the apical meristem and allows roots to push through the soil without damaging the cells of the root hairs.
Why do root cells elongate rather than expand?
Root cells elongate because of the circular arrangement of cellulose fibers in parallel bands in their cell walls.
How do cells elongate?
Cells elongate by taking up water, and as they do, the cellulose fibers separate, somewhat like an expanding accordion. The cells cannot expand greatly in width because the cellulose fibers do not stretch much.
For what does primary growth account?
Primary growth accounts for the lengthwise growth of the plant.
By what is the thickness of stems and roots caused?
The increase in thickness in roots and stems is caused by secondary growth along lateral meristems.
What happens to the cells left behind during elongation of the apical meristem?
The cells left behind during the elongation of the apical meristem become axillary bud meristems.
What causes the increase of girth in woody plants?
The increase in girth in woody plants is caused by lateral meristems that induce secondary growth.
What are tissues produced by secondary growth called?
Tissues produced by secondary growth are called secondary tissues. In secondary growth, vascular cambium gives rise to secondary xylem to its interior and secondary phloem to its exterior.
What gives wood its characteristic hardness and strength?
The secondary xylem has thick walls rich in xylem, that give wood its characteristic hardness and strength.
From what do annual growth rings in trees result?
Annual growth rings result from the layering of secondary xylem.
Why can a tree's age be estimated by counting its rings?
A tree's age can be estimated by counting its rings because each year a new ring of wood forms.
For what purpose to mature cork cells function?
Mature cork cells are dead and have thick, waxy walls that protect the underlying tissues of the stem from water loss, physical damage, and pathogens.
How is bark defined?
Bark is everything external to the vascular cambium. Bark is continuously shed as secondary growth continues and the tree expands.
What are the living parts of a tree trunk?
The living parts of a tree trunk are the vascular cambium, the cork cambium, and the cells in the wood rays.
I have just finished landscaping my yard and have a rather large area of exposed soil. Which group of plants should I plant to minimize erosion?
You have just collected a plant with a large, underground structure. How can you tell if it is a modified shoot or a root?
Look for either buds or root hairs.
Under ideal environmental conditions, a plant has produced much more carbohydrate than it needs to survive. Where will this surplus likely go in the plant body?
Which of the following plant cell types has a role similar to that of bone cells in animals?
The meristems of plants allow for indeterminate growth in plants. What cell type must be found in the meristematic region for this to occur?
Why would an angiosperm plant expend the energy to produce pollen grains with the sperm cells encapsulated inside?
to provide a way to get the sperm to the egg in the absence of liquid water
Why do angiosperms expend great amounts of energy to produce a seed when seedless plants were so successful?
The seed contains an embryonic plant and a food source for its development in one compact, hardy structure.
I have just picked a red, ripe, juicy tomato, and I want to plant the seeds. I quickly remove the seeds and plant them while they are still damp with some of the remains of the fruit. I just know they will quickly germinate and grow to produce new tomato plants. I keep the soil moist, and to my dismay, I still have no tomatoes after waiting a year. What do you think has happened?
Something in the fruit hinders seed germination.
In some biomes (types of ecosystems), frequent fires destroy plant life, but it is quickly replaced with new growth. The intense heat must stimulate enzymes in seeds that _____.
What part of a leaf is specialized for photosynthesis?
The mesophyll in the ground tissue of a leaf is specialized for photosynthesis.
If you pound a nail into a tree 3 feet off the ground and come back to find it in 20 years, it will be _____.
3 feet off the ground and more deeply embedded in the tree because of apical meristems at the top of the tree, the trunk at the bottom won't get taller.
A vandal killed a historic oak tree on the village green by girdling it with a chain saw. He cut through the bark and into the sapwood all the way around the tree. Why did the tree die?
The roots could not get food.
In what order would you pass through tissues when moving from the pith to the epidermis in a plant possessing secondary vascular tissue?
primary xylem, secondary xylem, vascular cambium, secondary phloem, primary phloem
In the process of pollination, pollen grains are transferred from the ___ to the _____.
In the process of pollination, pollen grains are transferred from the _____ to the _____.
Usually, the number of chromosomes in a flower's egg nucleus is _____ the number of chromosomes in a flower's pollen nucleus.
the same as
After fertilization the _____ develops into a seed and the _____ develops into a fruit.
Why do seeds need water to germinate?
Seeds need water to germinate because following hydration, enzymes break down stored food and make it available for the embryo.
Plants growing in harsh environments such as deserts, sand dunes, and arctic tundra often reproduce vegetatively. This is because______.
Vegetative reproduction is not as risky as making seeds.
In an angiosperm, what do sporophytes produce and where do they produce them?
Sporophytes produce haploid spores in anthers and ovules.
What does the embryo sac contain?
The embryo sac contains one large cell with two haploid nuclei, three antipodals, and two synergias.
What happens to the generative cell while the pollen tube grows down the ovary?
While the pollen tube grows down the ovary, the generative cell divides by meiosis, forming two sperm.
What is a simple fruit?
A simple fruit is a fruit that derives from a single flower with one carpel.
What are examples of fleshy fruit?
Fleshy fruit are apples, blueberries, squash, olives, and citrus.
What is an aggregate fruit?
An aggregate fruit is a single flower with multiple carpels. Ex: Raspberry.
Why is vegetative propagation (asexual reproduction of plants) possible?
Vegetative propagation is possible because meristem tissues grow indefinitely and parenchyma cells can differentiate into different cell types.
What is an ovary?
An ovary is the basal portion of a carpel in which the egg-containing ovules develop.
What happens once the pollen tube enters the ovary and releases the two sperm into the female gametophyte?
When the pollen tube enters the ovary and releases the two sperm into the female gametophyte, one sperm fertilizes the egg, and the other fuses with two nuclei in the center of the ovule to form a triploid cell that will develop into a food supply called endosperm.
How does the zygote develop into a sporophyte embryo?
The zygote divides by mitosis to form a sporophyte embryo with a rudimentary root and one or two small seed leaves.
How are pollen grains developed?
In the anther, each spore (n) divides once by mitosis to form two haploid cells. A tough wall forms around the outside, creating the male gametophyte, or pollen grain.
What does double fertilization do?
Double fertilization converts the large central cell from diploid to triploid, while the egg becomes a diploid zygote. The surrounding integuments remain diploid as they were before fertilization.
When has the seed officially germinated?
When the root emerges, the seedling has officially germinated.
How do beans protect themselves while pushing through the soil after germination?
The cotyledons enclose the delicate shoot tip until the emerge from the soil. The shoot forms a hook that pulls the cotyledons through soil rather than pushing. Light tells the shoot that it has emerged from the soil; the hook straightens and the cotyledons unfold.
How do peas protect themselves while pushing through the soil?
Pea keeps the cotyledons underground where they might be less subject to attack from animals. The pea shoot bends its stem into a hook that leads the way through the soil, so the the tip and leaves are pulled, not pushed, through the soil.