Biology Test 5

Roots

- Anchor plants into the ground, prevents erosion, and absorb water and dissolved nutrients from the soil - Works with soil bacteria and fungi in mutualistic relationships that help the roots absorb water and dissolved nutrients

Heartwood

- As the stem grows thicker, the older xylem near the center of the stem no longer conducts water and becomes heartwood. Heartwood darkens with age because it accumulates colored deposits. (Old xylem that no longer conducts fluid but helps support the tree). Heart = center of tree

Phloem

- Carries food ( nutrients) from areas engaged in photosynthesis to parts of the plant that need the food. - Has sieve tube elements - The main cells are called sieve tube elements the transport of sugars relies on the assistance of companion cells, that support the phloem cells and aid the movement of substances in and out of the phloem - The transport of phloem can go up or down.

Xylem

- Carries water and minerals from the soil to the roots to the rest of the plant ( Xylem can only travel up) - Water goes into the plant, and into the leaves, and then back into the atmosphere - Made of tracheids and vessel elements - Cells are dead at maturity because they are hollow to allow better movement of water Moves water and minerals from the soil into the roots and up

Cambium (Cork, Vascular)

- Cork: Produces the outer covering of stems. Also produces cork, which is the bark. - Vascular: Produces vascular tissue and increases the thickness of stems over time. Produces the new xylem and phloem.

What are the primary functions of the main tissue systems of seed plants?

- Dermal tissue = protective outer covering of a plant - Vascular Tissue = supports the plant body and transports water and nutrients throughout the plant. Forms a system of pipliek cells that help support the plant and serve as its "bloodstream" - Ground Tissue = Produces and stores sugars, and contributes to physical support of the plant

Importance of transpirational pull

- Even on a hot day, a small tree many lose as much as 100 liters of water to transpiration - The hotter and drier the air, and the windier the day, the greater the amount of water lost. - As a result, the plant draws up even more water from the roots.

Carpels

- Innermost floral part - female part of the flower - Carpels have broad bases ( ovaries - where female gametophytes are produced), stalks called styles, and the stigma at the top ( specialized to capture pollen)

Ground Tissue

- Just inside the epidermis - Makes/stores sugars - Supports the plant in addition to the vascular system - Most is parenchyma - Is also found everywhere ( in the leaf, stem, and roots)

Dermal Tissue

- Responsible for protecting the plant - Dermal tissue is found everywhere ( in the leaf, stem, and roots) - Dermal tissue in a young plant consists of a single layer of cells called the epidermis, which is covered with thick waxy layer called the cuticle, which protects against water loss - Dermal tissue in an older plant may be covered with bark -Has root hairs which produce a larger surface area that allows water and minerals to enter

Look at a seed and determine how it might be best dispersed based on its structure.

- Seeds in nutritious fruits: dispersed by animals (ex: watermelon - eat and poop or stuck in fur) - Seeds in lightweight fruits: dispersed by wind (ex: dandelion, winged fruit of maple) - Seeds in buoyant fruits: dispersed by water (ex: coconut, mangrove)

Stems

- Stems produce leaves, branches, and flowers; stems hold leaves up to the sun; and stems transport substances throughout the plant - Carries a defensive system that protects the plant against predators and disease - Contains tissue that lift water from the roots up to the leaves and carry the products of photosynthesis from the leaves back down to the roots - Parts of a stem Nodes = where leaves are attached Buds = contain apical meristems that can produce new stems and leaves ( found where leaves attach to the nodes)

Transpiration

- The major force in water transport - The evaporation of water from leaves - As water evaporates through open stomata, the cell walls within the leaf begin to dry out. Then the dry cell walls draw water from cells deeper inside the leaf. The pull extends into vascular tissue so that water is pulled up through xylem.

Leaves

- The structure of a leaf is optimized to absorb light and carry out photosynthesis. Most leaves have a thin flattened part called the blade that maximizes the amount of light the leaf can absorb. - Plant's main photosynthetic organs - Also has adjustable pores that help conserve water while still allowing oxygen and carbon dioxide to enter and exit the leaf

Pollination

- The transfer of pollen to the female portions of the flower - Some angiosperms are wind pollinated, and some are animal pollinated - wind pollination is less efficient because it relies on favorable weather and sheer numbers of pollen grains

Vascular Tissue

- Two types: Xylem and phloem - Found everywhere ( in the leaf, stem, and roots)

Petals

- found just inside sepals - brightly colored and shaped to attract pollinators to the flower

Stamens

- male part of the flower - Each stamen consists of a stalk called a filament with an anther at it's tip

Sepals

- outermost circle of the flower - encloses the bud

How are tissues distributed in a plant root?

A root has an outside layer, the epidermis, and a central cylinder of vascular tissue. Between the these two tissues lies a large area of ground tissue.

Relate a tree's rings to its growth.

A tree's age can be measured by counting its growth rings - each ring is produced by a year of growth. - Thick rings = Good weather conditions (lots of water) - Thin rings = not favorable conditions

Sapwood

Active in fluid transport, and is usually lighter in color. Surrounds the heartwood.

How are the three main organs of seed plants similar in structure?

All contain the same three tissues. ( Dermal, vascular, and ground tissue)

Bark

All of the tissue in a mature stem, found outside the vascular cambium. The bark includes the phloem, the cork cambium, and cork.

Be able to describe the functions of the different meristems.

Apical meristem = cells divide, which causes plant to grow from roots and top of stem; cambium meristem = lateral growth: grows vascular tissue (vascular cam.) and grows cork (cork cam.)

cohesion

Attraction between molecules of the same substance - Water cohesion is especially strong because of the tendency y water molecules to form hydrogen bonds with each other

Fibrous Root

Begins with one primary root, however, soon it is replaced by any equally sized branch roots that grow separately from the base of the stem. They branch to such an extent that no single root grows larger than the rest. Prevents topsoil from being washed away by heavy rain. Example: grasses.

Active Transport

Brings minerals from the soil into the plant. The high concentration of minerals in the plant cells causes water molecules to move into the plant by osmosis.

Vegetative Reproduction

Enables a single plant to produce offsprings genetically identical to itself

What are the main tissues in a mature root?

Epidermis ( outside layer), vascular tissue and ground tissue

Which single factor is most important in pulling water toward the top of a tall tree

Evaporation of water through stomata

Plant Propagation

Farmers use cutting or grafting to make many identical copies of a plant or to produce offsprings from seedless plants

Meristem

Growth areas in a plant - Regions of unspecialized cells in which mitosis produces new cells that are ready for differentiation. - 2 types --Apical Meristems ( where primary growth occurs) Root and Shoot. (Growth in plant height and root length) --Lateral Meristems ( where secondary growth occurs) - 2 types: Vascular Cambium, and Cork Cambium) - If someone cuts the apical meristem, it means no more growth from that meristem ( you can still have side growth, but no more from that meristem) -New cells pushed out of the meristem are unspecialized and have thin cell walls, however gradually they develop mature cells with specialized structures and functions

Know how leaves exchange gas with the atmosphere and what leaf structure plays a role in that gas exchange.

Leaves take in CO2 and release oxygen during photosynthesis because when plant cells use the food they make they take in CO2 and release oxygen. Leaves allow gas exchange between spaces in spongy mesophyll and by opening stomata.

Know characteristics that distinguish monocots and eudicots.

Monocot: 1 cotyledon (1st leaf produced by plant embryo), parallel veins, floral parts = multiples of 3, scattered vascular bundles, fibrous roots Dicot: 2 cotyledons, branched veins, floral parts = multiples of 4 or 5, ringed vascular bundles, taproot

Where does photosynthesis occur?

Photosynthesis happens in the chloroplasts in leaves, which are in the spongy and palisade mesophyll - that's where the CO2 goes as well.

Pulling it all together

Plants pull water upward using cohesion and adhesion. Water is attracted to the walls of the tube due to adhesion, because the xylem tissue is lined with cellulose cell walls, which adheres to the water strongly. The water molecules are also attracted to one another due to cohesion. So when transpiration removes water from the leaves, strong adhesion forces pull in water from the wet interior of the leaf.

Distinguish between primary and secondary growth.

Primary growth is an increase in the length of the shoot and root due to apical meristems found in the stem and roots that divide. Secondary growth is characterized by an increase in thickness of the plant ( lateral growth) due to lateral meristems ( The vascular cambium, and the cork cambium). Secondary growth produces new phloem on the outside, and new xylem on the inside). - secondary growth is IN DICOTS and thickens the plant.

What are the three main organs of seed plants?

Roots, stems, and leaves

What are the three principal organs of seed plants?

Roots, stems, and leaves

Know the functions of roots, stems and leaves.

Roots: Roots anchor plants in the ground, and store food and nutrients. Stems: Stems produce leaves, branches, and flowers; hold up leaves to the sun; and transport substances throughout the plant .Stems also have a defensive system that protects the plant against predators and disease. Leaves: Are the plants main photosynthetic organs. The broad flat surfaces of many leaves (usually called the blade) increase the amount of sunlight plants absorb. They also have adaptations that protect them against significant amounts of water loss, such as adjustable pores that allow oxygen dioxide to enter and exit the leaf, but limit the amount of water loss.

Fibrous and Taproots

Same functions for both: hold plant into the ground, facilitate the bringing of minerals into the plant

Compare the advantages and disadvantages of sexual reproduction versus asexual reproduction in flowering plants

Sexual: new combinations of genetic traits are produced that help plants survive changing environmental condition, but it takes time and resources to produce offspring. Asexual: plants grow rapidly in a favorable environment, but it does not result in new combinations of traits that may aid survival

Explain factors that influence the rate of plant transpiration

Some factors that influence the rate of plant transpiration include environmental factors such as heat and humidity, as well as wind.

Adhesion

The attraction of unlike molecules

What are the major forces that transport water in a plant?

The combination of transpiration and capillary action are the major forces that move water through the xylem tissues of a plant

Diffusion

The movement of water from an area of high concentration to an area of low concentration down a concentration gradient until equilibrium is reached.

Taproot

The primary root grows long and thick, and gives rise to smaller branch roots. Examples include oak and hickory trees, as well as carrots and dandelions.

How is the structure of cells in a root's transport system different from the structure of cells making up the epidermis?

The root's transport system cells allow one way absorption of water and nutrients.

Explain why most plants have their stomata on the underside of their leaves

To reduce the amount of transpiration, plants have their stomata on the underside of their leaves to reduce contact with the sun. If it was on the top it would loss water faster, and the stomata would close faster. ( Water lilies have all their stomata on the top of its leaves, this is because it isn't concerned with water loss. They are on the top so they can have gas exchange)

Explain what transpiration is and why it matters to plants. What is a good thing about transpiration? What is a problem with transpiration?

Transpiration is water loss by plants through leaves. Good thing = gas exchange so you have photosynthesis. Bad Thing = if it doesn't pull more water up from the roots, the plant can become water deficient, and in some cases die.

What type of environment would result in the greatest rate of transpiration

Warm, Light Breezy conditions

How is osmosis involved in the absorption of water and nutrients?

Water moves into the vascular cylinder by osmosis

Understand how guard cells regulate the opening of stomata

When water is abundant, water flows into leaf, raising water pressure in guard cells, so stoma opens. When water is scarce, water pressure decreases, so guard cells' inner wall closes.

Sink

Where sugars are stored

Source

Where the sugars are from

Be able to explain what substance(s) xylem and phloem transport, from what source they transport the substance(s) and where the substance(s) ultimately go.

Xylem transports waters and minerals from the soil to the roots to the rest of the plant. Xylem can only travel up. Phloem carries food ( nutrients) from areas engaged in photosynthesis to parts of the plant that need the food. Phloem can go up or down

Root cap

\ The root tip is covered by a tough root cap that protects the fragil meristems as the root tip forces its way through the soil. As the root grows, the root cap also secretes a slippery substance that eases the progress of the root through the soil. Cells at the very tip are always being scraped away, and new root cap cells are added by the meristem.

How do fruits form?

as angiosperm seeds mature, ovary walls thicken to form a fruit that encloses the developing seeds

How might the presence of meristems explain the ability of plants to regenerate from cuttings?

because meristems can differentiate in each tissue system of a plant, a cutting that contains meristems that can form a new plant.

Osmosis

diffusion of water through a selectively permeable membrane

Angiosperms

flowering plants: flowers cost energy but attract pollinators, fruit cost energy but help spread plant with seeds

Epidermis

layer of cells that make up dermal tissue

Gymnosperms

pines and allies - reproduce using pinecones

What is the function of meristems?

produce new cells by mitosis

Capillary action

tendency of water to rise in a thin tube

Root Hairs

thin cellular projections that produce large surface area that allow water and minerals to enter

What two forces are responsible for 90 percent of the upward flow of water through a plant?

transpiration and capillary action