ASU Biology of Plants-Exam 1 with Dr. Huss

Plants are very diverse in shape, size, habitat, & ways of reproducing and dispersing themselves. Describe some examples.

Plant types: Non-vascular vs. vascular plants Non-seeded vs. seeded plants Non-flowering vs. flowering plants Herbaceous vs. Woody -Grasses, forbs, and herbs -Vines, shrubs, bushes, and trees

Thus far, approximately how many species of plants have been described by biologists?

There are about 250,000 species of plants that have been described by biologists.

Photosynthetic autotrophs are polyphyletic, having multiple genealogies. What are some examples?

examples: blue-green algae, cyanobacteria, various members of the Kingdom Protista, eukaryotic algae, green algae, euglenoids, brown algae, diatoms, dinoflagellates, red algae, and eukaryotic multicellular plants like mosses, ferns, club mosses, horsetails, gymnosperms, and angiosperms --------------Algae, along with plants and some bacteria and fungi, are autotrophs. Autotrophs are the producers in the food chain, meaning they create their own nutrients and energy. Kelp, like most autotrophs, creates energy through a process called photosynthesis.

What are some major characteristics or attributes of plants?

The four main characteristics of plants are photosynthesis, cuticle, cell Walls and reproduction.

What is the meristem of a plant?

localized regions of cell division in the plant body

Roots

Collect minerals and water

Stem

Carry materials up and down the plant

Leaves

Use sunlight to make food

Stamen

Male reproductive organ in plants

Pistil

Female reproductive part of a flower

Anthers

Top of male stamen; makes pollen

Filaments

Support the anther

Stigma

Sticky top of the pistil; holds pollen

Style

the tube-like structure that holds up the stigma

Ovary

a flower structure that encloses and protects ovules and seeds as they develop

Ovules

Structure that develops within ovary of seed plant and contains female gametophyte

Petals

attract pollinators and are usually the reason why we buy and enjoy flowers

Sepals

are the green petal-like parts at the base of the flower. These help protect the developing bud

What are examples of structures that hold seeds or spores in different types of plants?

Reproductive structures like sporangia, cones, fruits

What major reasons explain why many plant species are highly-branched in their shoot and root systems?

Plants are highly branched to maximize surface area for absorption. Branching roots enables them to extend and to increase their surface in contact with the soil.

Be able to interpret the 'Energy and Resource Flow Chart' presented in class. What differentiates producers, decomposers, and consumers from one another?

List several ways of how plants are beneficial to all life on earth

Three reasons plants are beneficial to Earth: Food, resupply Oxygen, maintain climate, natural medicine, absorbing carbon dioxide, providing nutrients to animals, and regulating the water cycle — all things we need to sustain life on Earth.

What are some common uses of plants by humans?

source of medicine, spices, fibers, paper, clothing, lumber, oxygen, fuel (coal and wood), toothpicks, toilet paper, paper money, soft drinks, drugs, and so on.

What are the geographic origins of some common economically- and agriculturally-important plants?

maize (central Mexico) rice (China) , wheat (Iraq) potatoes (Peru)

Why did hunter/gathers in ancient times need a basic understanding of botany?

to distinguish poisonous plants from edible ones

How did practice of agriculture change the way that humans made their living? What impact did agriculture have on human society over time?

Agriculture changed human society so that they didn't have to travel to find the food that was needed

Discuss two hypotheses about the near simultaneous discovery of agriculture in different parts of the world?

Two hypotheses about origin of agriculture:

- Independent discovery in different parts of world at the same time.

- Diffusionist hypothesis - discovery originated in one part of the world and spread from one civilization to another.

Who is considered the founder of Chinese agriculture?

Shen Nung born in 2737 B.C. Wrote books on drugs and medicine from plants

Who is sometimes called the 'father of botany' and what were some of his major written works?

Theophrastus; "History of Plants" and "Causes of Plants"

Why is Dioscorides' book "Materia Medica" considered a first?

Dioscorides wrote the "Materia Medica" in the 2nd century A.D., which contained illustrations of plants, just as many modern field guides of wild plants (and other organisms) do today.

Who coined the word 'cell'?

Robert Hooke

Who was the first to study living organisms under a lens?

Antonie van Leeuwenhoek

What are some examples of the scientific disciplines of botany or plant biology?

plant taxonomy, physiology, ecology, morphology, anatomy, developmental biology, cytology, genetics, ethnobotany, economic botany, genetic engineering. bacteriology, the study of bacteria; mycology, the study of fungi; phycology, the study of algae; bryology, the study of mosses and liverworts; pteridology, the study of ferns and their relatives; and paleobotany, the study of fossil plants.

What are the steps in scientific method?

Establish a problem or question

Hypothesize

Experiment

Conclusion

What is a hypothesis and how does this compare to the use of the term "fact" and "theory" in the practice of science?

A hypothesis is a testable "educated guess" to answer a question or explain a problem. A fact can be empirical (observed either directly with your senses or indirectly with your senses) or it can be inferred (based on a reasonable solution. A theory is equivalent to speculation and is an explanation based on numerous experiments to explain how the world works.

What are some few characteristics that separate living organisms from non-living matter?

All living things breathe, eat, grow, move, reproduce and have senses. Non-living things do not eat, grow, breathe, move or reproduce.

Describe Robert Hooke's findings upon examining cork tissue from the oak tree

When he used a set of lenses to look at the piece of cork, he saw little holes that reminded him of monastery rooms so he decided to call them "cells"

Referring to the use of a microscope, what are the definitions for the terms, magnification, resolution, and contrast?

Magnification-is the ability of a microscope to produce an image of an object at a scale larger (or even smaller) than its actual size. Resolution-the ability of a microscope to distinguish details of a specimen or sample. Contrast-the difference in light intensity between the image and the adjacent background relative to the overall background intensity.

Who dispelled the theory of spontaneous generation of life in the 1860s? What was the significance of this discovery?

Louis Pasteur disproved the theory of spontaneous generation. Spontaneous generation theory is an archaic scientific theory which stated that living organisms could arise from nonliving matter and that such a process was regular in nature. It also explained the origin of life from the nonliving subjects.

In the cell wall, cellulose forms micro & macro-fibrils which are held together by a glue-like substance called ______________________.

Pectin

What are the three main components of the primary cell wall?

cellulose, pectin, and hemicellulose

Where does the secondary cell wall exist and what materials make it up?

-Secondary walls are mainly found in tracheary elements and fibers in the primary xylem and the secondary xylem (wood) -Secondary cell walls are mostly made of cellulose, hemicelluloses, and lignin

What is the function of the plasmodesma (singular) or plasmodesmata (plural)?

They serve as communication portals between neighboring plant cells

What is the name of the region between cells that is made of pectin?

Middle lamella

The plasma membrane is semi-permeable. What is semi-permeable or differentially-permeable mean?

A membrane that allows the passage of small molecules but not of large molecules.

What is cytoskeleton of a cell?

Network of filaments that function to give strength, shape, and movement to cells

3 filaments: Actin, Intermediate, Microtubules

What is the fluid matrix that organelles are embedded inside a living cell?

Cytoplasm

What is the nucleus and what is its primary function?

Its the most prominent organelle.

Its function is to regulate gene expression, contains DNA

What is E.R. and what is the difference between the two types?

E.R. is Endoplasmic Reticulum. Irregular maze from a single membrane that is continuous with the nuclear membrane and surrounding a single lumen

Rough ER- synthesize proteins, contain ribosomes

Smooth ER- synthesize and metabolize lipids, NO ribosomes

What is the function of the Golgi apparatus or body?

Responsible for the modification of the proteins from the ER

Directs proteins to the proper site

Modification of proteins

What is another name for a dictyosome?

Golgi bodies

What are the housekeeping organelles of the cell?

The lysosomes

What organelles that breakdown organic compounds and waste products inside a cell?

Lysosomes are membrane-enclosed organelles that contain an array of enzymes capable of breaking down all types of biological polymers—proteins, nucleic acids, carbohydrates, and lipids.

What organelle performs aerobic respiration in a eukaryotic cell, including the living plant cell?

mitochondria

What are some examples of plastids and what function do these perform in a plant cell?

Large organelles that are associated with pigments and other storage products

Types:

Chloroplasts-contain chlorophyll (green pigment) and capture energy from sunlight to make food for the plant

Leucoplasts-used for storage of starch or oil in plants

-Amyloplasts (starch)/ Elaioplasts(oils)

Chromoplasts-contains pigments other than chlorophyll like orange and yellow

Large vacuoles are bound by a membrane called the tonoplast. What does a large vacuole contain?

May store water, waste products, food, and other cellular materials.

What is turgor pressure and why does it prevent leaves from wilting?

turgor is water pressure inside any plant cell. The fluid presses the cell membrane against the cell wall so that turgor is what makes living plant tissue rigid

Do plant cells have centrioles? How does this compare to that of animal cells?

Plant cells DO NOT have centrioles.......................... animal cells Do

What happens during cytokinesis?

Cytokinesis is the physical process that finally splits the parent cell into two identical daughter cells. During cytokinesis, the cell membrane pinches in at the cell equator, forming a cleft called the cleavage furrow.

What is nuclear division?

When a nucleus divides

Primary growth (cell division) occurs in what part or region of the plant body?

Meristems or the root tips

What is secondary growth? Would secondary growth likely occur in a herbaceous plant (e.g., grasses and forbs)?

Secondary growth is characterized by an increase in thickness or girth of the plant.-------Herbaceous (non-woody) plants mostly undergo primary growth, with hardly any secondary growth or increase in thickness

What are the major components of the cell cycle? What G1, S, and G2 refer to?

The cell cycle has two major phases: interphase and the mitotic phase--------------The G1 stage stands for "GAP 1". The S stage stands for "Synthesis". The G2 stage stands for "GAP 2".

When chromatin in a nucleus condenses, what individual structures are formed?

metaphase chromosomes

What is the difference between meristematic, simple, and complex tissues?

Meristematic-contains undifferentiated cells, which are the building blocks of the specialized plant structures. Simple-consist of cells that are structurally and functionally similar. Complex-is a kind of tissue that is made up of more than one type of cell, and all the cells coordinate to perform a common function.

What is the apical meristem and where is it located?

located at the tips of shoots and roots.----------give rise to the primary plant body and are responsible for the extension of the roots and shoots.

What type of meristematic tissue is responsible for secondary growth in wood plants (e.g., vines, shrubs, bushes, and trees)?

Vascular cambium and cork cambium

What allows grass to grow back after being cut after being mowed or nibbled on by a herbivore, or burned by a fire?

Photosynthesis

Where are parenchyma found and what is its use in a living plant?

Make up the inside of many non-woody plant structures including: stems, roots, and leaves.

Function: storage of food and water

What is difference between parenchyma, aerenchyma, and chlorenchyma?

Aernchyma-a spongy tissue that forms spaces/air channels in the leaves, stems, and roots of halophytic plants

Chlorenchyma-mechanical, supportive ground tissue in plants containing chloroplasts. Parenchyma- the simple permanent ground tissues that form the bulk of the plant tissue

Where is collenchyma found in a plant and what is its major function?

Often found under the epidermis, or outer layer of cells in young stems and in leaf veins

Function: provide structural support

fill in vacant spaces that will be used for later growth

Lignin is found in the thick cell walls in what type of tissue?

Complex Tissue: Specifically Xylem

What is the epidermis and what is its function?

the outermost, protoderm-derived layer of cells covering the stem, root, leaf, flower, fruit, and seed parts of a plant. The epidermis and its waxy cuticle provide a protective barrier against mechanical injury, water loss, and infection.

What are complex tissues? Give examples of types and functions.

Xylem and phloem are known as complex tissues as they are made up of more than one type of cells. The xylem distributes water and dissolved minerals upward through the plant, from the roots to the leaves. The phloem carries food downward from the leaves to the roots

What is the main function of the xylem?

it distributes water and dissolved minerals upward through the plant, from the roots to the leaves.

How does the structure of the xylem tissue contribute to its function in water transport?

Tubular shape with no cross walls which allows a continuous column of water + facilitates more rapid transport within the xylem vessels. There are two types - protoxylem (first formed xylem) + metaxylem (mature xylem) depending on pattern of lignin.

Secondary xylem is produced by what type of meristematic tissue?

Vascular Cambium

What does the phloem do in the plant body?

Transportation of food and nutrients such as sugar and amino acids from leaves to storage organs and growing parts of plant. This movement of substances is called translocation.

What is the periderm and what function does it serve for plants that exhibit secondary growth in their roots and stems?

The periderm acts as the first line of defense for a plant, protecting wood and phloem from stress. During secondary growth, through the increase in girth of plant organs, the periderm replaces the epidermis as the outermost tissue.

Give examples of some of the secretory structures of a plant.

NECTAR (flowers)

OILS (peanuts, oranges, citrus) from accumulation of glands and elaioplasts

RESINS (conifers)

LACTICIFERS (latex- milkweed, rubber plants)

HYDATHODES (openings for secretion of water)

DIGESTIVE GLANDS of carnivorous plants (enzymes)

SALT GLANDS that shed salt (especially in plants adapted to environments laden with salt.)

Review examples of the following figures from your notes, presentations, and textbook: e.g., cell wall components, typical plant cell, guard cell/stoma (stomata), xylem, and phloem.

...

Secondary growth occurs in what type of plants?

woody

In sclerenchyma tissue, are cells alive at maturity? Why or why not?

Dead at maturity because they have lost their protoplasts. Their cells cytoplasm, nucleus, and cell organelles are absent at maturity

What type of parenchyma tissue is found in water lilies? How does it help lily pads float on the surface of the water?

Arenchyma tissue makes up water lilies.

The groups of cells are loosely packed together with connected air spaces.

What cells regulate the activities of sieve tube elements or members?

Phloem cells

What substance makes up spindle fibers in the cytoskeleton of a cell and what purpose do these fibers serve?

The spindle fibers are microtubules, long strands of protein that move to each side of the cell. They extend out microtubules that are used to pull the chromosomes (condensed DNA pairs) apart and to each side of the cell, allowing the two daughter cells to be completely identical.

Name a few plants that are economically important because of their sclerenchyma (fibers), and name some common uses of these plants.

Hemp - rope, textiles, clothing, shoes, food, paper, bioplastics, insulation, and biofuel. Jute - Yarn and twine, sacking, hessian, carpet backing cloth and as well as for other textile blends. Flax - The seed, ground or whole, is used in baking breads, cookies, scones and is used with many meat dishes. It is sprinkled on salads, in salad dressings, cereal, cottage cheese or yogurt

What cell types or simple tissues converge to make up a complex tissue known as xylem? Phloem?

Xylem- Made up of: parenchyma, fibers, vessels, and/or tracheids, and ray cells.

Function: water conducting tissue

Phloem- Made up of: sieve-tube members (no nucleus at maturity, cytoplasm present), campanion cells, fibers, parenchyma, and ray cells.

Function: food conducting tissue

What is a tracheid and in what type of tree or group of plants would it commonly be found in the woody stem?

Tracheid- the water-conducting and mechanical supporting cells of gymnosperms.

What is a genet? A ramet?

Genet-a group of genetically identical individuals (plants, fungi, bacteria etc.) that have grown in a given location, all originating from asexual reproduction of a single ancestor; a group of ramets. Ramets-a number of clonally formed offspring.