1. List the Characteristics of an Angiosperm

Chapter 35

1. List the characteristics of an angiosperm.

Flowers and fruits, evolutionary adaptations that function in reproduction and the dispersal of seeds, characterize angiosperms.

2. Explain the differences between monocots and dicots.

Monocots have one cotyledon, the veins are usually parallel, vascular bundles are complexly arranged, have fibrous root system, and their floral parts are usually in multiples of three. Dicots have two cotyledons, the veins are usually netlike, they have vascular bundles arranged in ring, taproot usually present and their floral parts are usually in multiples of four or five.

3. Describe the importance of root systems and shoot systems to plants and explain how they work together.

Roots anchor the plant in the soil, absorb minerals and water, conduct water and nutrients, and store food. The shoot system consists of vegetative shoots, which bear leaves, and floral shoots, which terminate in flowers. Neither system can live without the other. Lacking chloroplasts and living in the dark, roots would starve from the photosynthetic tissues of the shoot system. Conversely, the shoot system depends on water and minerals absorbed from the soil by roots.

6. Describe how plant cells grow.

Meristems generate cells for new organs throughout the lifetime of a plant. Apical meriatems elongate shoots and roots through primary growth. Lateral meristems add girth to woody plants through secondary growth.

7. Distinguish between parenchyma and collenchyma cells with regards to structure and function.

Parenchyma cells, relatively unspecialized cells that retain the ability to divide, perform most of the plants metabolic functions of synthesis and storage. Collenchyma cells, which have unevenly thickened cell walls, support young, growing parts of the plant.

8. Describe the differences in structure and function of the two types of sclerenchyma cells.

The two forms of sclerenchyma cells are fibers and sclerids. Long, slender, and tapered, fibers usually occur in bundles. Sclerids are shorter than fibers and irregular in shape. Nutshells and seed coats owe their hardness to sclerids.

13. Describe the functions of the dermal tissue system, vascular tissue system and ground tissue system.

Dermal tissue protects the plant and sometimes-even help in the absorption of water and minerals. Vascular tissues functions in the transport and support, and ground tissues fill the space between the dermal and vascular tissue systems. Among the diverse functions of ground tissue are photosynthesis, storage, and support.

Using a diagram, describe the basic structure of a root, a stem, and a leaf.

Root

Stem

Leaf

Chapter 36

List three levels in which transport in plants occurs and describe the role of aquaporins.

Cellular Level

Tissue and Organs Level

Whole-Plant Level

Trace the path of water and minerals from outside the root to the shoot system.

Define water potential

The Physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure

Explain how solute concentration and pressure affects water potential

If a plant cell is immersed in a solution having higher water potential than the cell, osmotic uptake of the water can perform work. The potential in water potential refers to this potential energy, the capacity to perform work when water moves from a region of higher to a region of lower.

According to the transpiration-cohesion-adhesion theory, describe how xylem sap can be pulled upward in xylem vessels.

Describe both the disadvantages and benefits of transpiration.

Transpiration results in a tremendous water loss from the plant. The upward movement of water through the xylem replaces this water. Guard cells surrounding stomata balance the requirements for photosynthesis with the need to conserve water. Transpiration is a big force that helps pull water to the top of the plant, however, its downside is the great amount of water lost during the process.

List three cues that contribute to stomatal opening at dawn.

Light. Induces guard cells to take up K+ by:

Activating a blue light receptor which stimulates proton pumps in the plasma membrane

Driving photosynthesis in guard cells chloroplasts, making ATP available for the ATP driven proton pumps.

Decrease of CO2 in leaf air spaces due to photosynthesis in the mesophyll

An internal clock in the guard cells. This will make them open even if the plant is kept in dark

Describe environmental stresses that can cause stomata to close during the daytime.

There is a water deficiency resulting in flaccid guard cells.

Mesophyll production of absidic acid (a hormone) in response to water deficiency signals guard cells to close.

High temperature increases CO2 in leaf air spaces due to increased transpiration, closing guard cells.

Chapter 37

Describe the chemical composition of plants including:

a. Percent of wet weight as water: 80-85% of an herbaceous plant is water

b. Percent of dry weight as organic substances: 95% organic substances

c. Percent of dry weight as inorganic minerals: 5% minerals, to some extent determined by soil composition.

Distinguish between macronutrient and micronutrient.

Macronutrients are elements required by plants in large amounts. Micronutrients are elements required by plants in small amounts.

List the nine macronutrients required by plants and describe their importance in normal plant structure and metabolism.

Nitrogen, Potassium, Phosphorous, Calcium , Magnesium, Hydrogen, NO3-, H2PO4-, SO4-. Hydrogen ions in soil displace positively charged mineral ions from clay, making them available to plants. Potassium, Calcium and Magnesium adhere by electrical attraction to negatively charged clay molecules.

List the three mineral elements that are most commonly deficient in farm soils.

Nitrogen, Potassium and Phosophorous.

Describe the environmental consequence of overusing commercial fertilizers.

The overuse of commercial fertilizers are not retained in the soil for long, so the minerals not used by the plants are leached off by rainwater or irrigation and drained into the groundwater and eventually pollute streams and lakes.

Describe modifications for nutrition that have evolved among plants including parasitic plants, carnivorous plants, and mycorrhizae.

Parasitic plants have evolved to grow projections called haustoria to steal xylem sap

from the vascular tissue of the host tree. Carnivorous plants, due to poor soil, have

developed a system where they receive carbohydrates from photosynthesis and nitrogen

and minerals by killing and digesting insects; insect traps have evolved by the

modification of leaves.

Chapter 38

Outline the angiosperm life cycle.

AP Biology book page 728 figure 34.1

List the four floral parts in their order from outside to inside of the flower.

Sepals, petals, stamens and carpels.

From a diagram of an idealized flower, correctly label the following structures and describe their function:

a. Sepals c. Stamen: filament and anther

b. Petals d. Carpel: style, ovary, ovule and stigma

Explain by which generation, structures, and process gametes are produced.

Pollen grains develop within the sporangia of anthers at the tips of stamens. Within each sac are numerous microsporocytes, the diploid cells that give rise to pollen. Meiosis forms four haploid microspores from each microsporocyte. Each microspore then undergoes a mitotic division, giving rise to a pollen grain that becomes a mature male gametophyte when the cell divides to form sperm. The embryo sac develops within an ovule. A diploid cell, a megasporocyte, divides by meiosis and gives rise to four cells where only one survives to become the megaspore. The mitotic divisions of the spore form the embryo sac.

Describe the formation of a pollen grain in angiosperms.

Pollen grains develop within the sporangia of anthers at the tips of stamens. Within each sac are numerous microsporocytes, the diploid cells that give rise to pollen. Meiosis forms four haploid microspores from each microsporocyte. Each microspore then undergoes a mitotic division, giving rise to a pollen grain that becomes a mature male gametophyte when the cell divides to form sperm.

Distinguish between pollination and fertilization.

Pollination is the first step towards fertilization; it leads to it. For the egg to be fertilized, the male and female gametophytes must meet and unite their gametes through pollination, the process of placing pollen onto the stigma of a carpel. Once the stigma identifies a pollen grain as compatible, the pollen grain produces a tube that extends down between the cells of the style toward the ovary.

Describe how pollen can be transferred between flowers.

Pollen can be transferred between flowers by the wind or animals. Pollination occurs when a pollen released from anthers and carried by wind or animals land on sticky stigmas at the tips of carpels (though not necessarily on the same flower or plant). Fruits, carried by wind or animals, help disperse seed some distance from their source plant.

From the diagram, identify the following structures of a seed and recall a function for each:

Seed coat- protects the embryo and its food supply

Embryo- female gametophyte of angiosperms

Hypocotyl- Terminates in the radicle

Radicle- embryonic root.

Epicotyl- above the cotyledons

Plumule- consists of the shoot tip with a pair of miniature leaves.

Endosperm- surrounds the embryo

Cotyledons- surrounds the embryo

page 735 in the AP Biology book, Figure 34.7.

Explain how a monocot and dicot seed differ.

A monocot seed by a monocot seed has a single cotyledon, called a scutellum. This seed leaf is very thin but has a large surface area, the better to absorb nutrients from the endosperm during germination. A dicot seed retain their food supply and have cotyledons that are very thin.

Describe several functions of fruit and explain how fruits form.

Fruits protect the enclosed seeds and aids in their dispersal by wind or animals. The fruit begins to develop after pollination triggers hormonal changes that cause the ovary to grow tremendously. The wall of the fruit becomes the pericarp, the thickened wall of the fruit. As the ovary grows, the other parts of the flower wither away in many plants. This formation of the flower parallels the development of the seeds.

Chapter 39

List five classes of plant hormones, describe their major functions, and recall where they are produced in the plant.

AP Biology book page 753, Table 35.1, An Overview of Plant Hormones.

Explain how a hormone may cause its effect on plant growth and development.

Hormones may cause its effect on plant growth and development by plant hormones help coordinate growth, development, and responses to environmental stimuli. In general, these hormones control plant growth and development by affecting the division, elongation, and differentiation of cells.

Define circadian rhythm and explain what happens when an organism is artificially maintained in a constant environment.

A physiological cycle of about 24 hours, present in all eukaryotic organisms, that persists even in the absence of external cues.

Define photoperiodism.

A physiological response to day length, such as flowering plants.

Distinguish among short-day plants, long-day plants, and day-neutral plants; give common examples of each; and explain how they depend upon critical night length.

AP Biology Book page 765, Figure 35.13 Photoperiodic control of flowering.