Biology 2 Plant Test

What are two examples of seed plants?

What are two examples of seed plants?

Gymnosperms and Angiosperms.

What are two types of vascular tissue and what do they do?

Xylem- conducts most of the water and minerals from the roots upward.

Phloem- consists of living cells and distributes sugars, amino acids, and other organic products.

What is the alternation of generations?

The life cycles of all land plants alternate between two generations of distinct multicellular organisms: gameophytes and sporophytes.

Describe the alternation of generations cycle.

1. The gameophyte produces haploid gametes by mitosis.

2. Two gametes unite( fertilization) and form a diploid zygote.

3. The zygote develops into a multicellular diploid sporophyte.

4. The sporophyte produces unicellular haploid spores by meiosis.

5. The spores develop into multicellular haploid gamephytes.

What is the stomata?

Allows for gas exchange.

What is the female and male gametangia called?

Archegonia- female (eggs)

Antheridia- male (sperm)

What is the apical meristem?

The growth in length is sustained throughout the plants life by _____________, localized regions of cell division at the tips of roots and shoots.

What does the waxy cuticle do?

The cuticle acts as a water proofing, helping prevent excessive water loss from the above ground plant organs, while also providing some protection from microbial attack.

What is the heterosporous spore production?

Megasporangium on megasporophyll -> Megaspore -> Female gameophyte -> Eggs

Microsporangium on microsporophyll -> Microspore -> Male gameophyte -> Sperm

What was the carboniferous period?

Formation of roots results in the weathering of rocks and the formation of calcium carbonates and magnesium.

Carbonates, reducing CO2 levels and resulting in cooler temps.

What is the homosporous spore production?

Sporangium on sporophyll -> single type of spore -> Typically bisexual gameophyte -> egg

-> sperm

Seed plants and most mosses are

heterosporous

Most seedless vascular plants are

homosporous

What is pollen?

Microsporocytes are the pollen mother cells and they produce haploid microspores that develop into pollen grains that contain immature male gameophyte.

Evolution of pollen- marks the break in water dependency for reproduction.

Resistant to desiccation; dispered by wind.

Megasporocytes

Produce haploid megaspores inside the ovule, and the surviving megaspores develops into a female gameophyte

What are microsporocyte and sporopollenin?

Microsporocyte- produces (n) microspores that develops into pollen grains.

Sporopollenin- protects pollen grain

What does a seed coat do?

Seed coat results in protection against dessicaton, fungus, and bacteria.

The embroyo is always _______.

Diploid.

Through what cellular process does pollen grains form in gymnosperms?

Mitosis.

The endosperm

is the result of a sperm nuclei and two polar bodies joining to for a 3N tissue in the seeds of angiosperms.

In addition to seeds, which of the following characteristics is unique to the flower producing plants?

flowering, fruiting and double fertilization.

Where does the mass of a plant come from?

Carbon dioxide

Of the following individuals which exhibits the life history of the sporophyte being dependent on the gameophyte?

moss

Gametophyte=

Produces pollen grains through=

haploid; mitosis

What is the difference between monocot and dicot?

Monocot- one embryo, veins parallel, vascular tissue scattered, root system (fibrous), pollen grain with 1 opening, and floral organs in multiples of 3.

Dicot- two embryos, veins netlike, vascular tissue in ring, root system (taproot), pollen grain with 3 openings, and floral organs with multiples of 4 or 5.

Complete flowers vs incomplete flowers

Complete flowers contain all four floral organs

Incomplete flowers lack one or more floral organs, for example stamens or carpels

Clusters of flowers are called inflorescenses.

What are the four general trends that can be seen in the evolution of flowers

-Bilateral symmetry

-Reduction in the number of floral parts

-Fusion of floral parts

-Location of ovaries inside receptacles

Where are the ovaries located?

Inside receptacles

What does the angiosperm life cycle include

-gametophyte development

-Pollination

-Double fertilization

-Seed development

Self-incompatibility

A plant's ability to reject its own pollen.

Recognition of self pollen triggers a signal transduction pathway leading to a block in growth in the pollen tube.

Coevolution

is the joint evolution of interacting species in response to selection imposed by each other.

The shapes and sizes of flowers often correspond to the pollen- transporting parts of their animal pollinators.

Bee Dependence

Plants such as blueberries, cherries, melons, apples, broccoli are 90% dependent on bees for pollination.

Almonds 100%

Abiotic pollination vs pollination by bees

abiotic pollination by wind

pollination by bees

pollen get dispersed by

wind and water

One sperm will fuse with the egg, forming .....

a zygote (2n)

Gymnosperm: Life Cycle

Plants receive signals from the environment and respond by altering _________.

Growth and development

Plant hormones

are chemical signals that modify or control one or more specific physiological processes within a plant.

are produced in very low concentrations, but can have profound effects on growth and development

Major Plant hormones include

auxin, cytokinesis, gibberellins, abscisic acid, ethylene

Tropism

Any response resulting in curvature of organs toward or away from a stimulus

Phototropism

a plant's response to light

Auxin

stimulates proton pumps in the plasma membrane

Expansins

Enzymes that loosen the walls fabric

Phyllotaxy

the arrangment of leaves on the stem

Cytokinins

are produced in actively growing tissues such as roots, embryos, and fruits

work together with auxin to control cell division and differentiation

Apical dominance

a terminal buds ability to suppress development of auxillary buds

Cytokinins

slow the aging of some plant organs by inhibiting protein breakdown, stimulating RNA and protein synthesis, and mobilizing nutrients from surrounding tissues

Gibberellins

have a variety of effects, such as stem elongation, fruit growth, and seed germination

are produced in young roots and leaves

stimulate growth of leaves and stems

Germination

After water is imbedded release of gibberellins from the embryo signals seeds to germinate

Abscisic Acid

Slows growth

two of the many effects are seed dormancy and drought tolerance

Seed dormancy

ensures that the seed will germinate only in optimal conditions

ABA

is the primary internal signal that enables plants to withstand drought

accumulation causes stomata to close rapidly

Ethylene

response to stresses such as drought, flooding, mechanical pressure, injury and infection

(fruit ripening)

Senescence

programmed death of cells or organs

Apoptosis

the programmed destruction of cells, organs or whole plants

Leaf Abscission

A change in the balance of auxin and ethylene

Process that occurs in autumn when a leaf falls

Fruit Ripening

a burst of ethylene production in a fruit

ethylene triggers ripening, and ripening triggers release of more ethylene

Auxin

Stimulates cell elongation; regulates branching and organ bending

Cytokinins

Stimulate plant cell division; promote later bud growth; slow organ death

Gibberellins

Promote stem elongation; help seeds break dormancy and use stored reserves

Abscisic Acid

Promotes stomatal closure in response to drought; promotes seed dormancy

Ethylene

Mediates fruit ripening and the triple response