Laboratory Teaching Assistant: Wanchad Sumanochitrapon

Office: FSA 153 Tel: 83076

Email: wsumano@ilstu.edu

Textbook: MSWord files on CD

Lab guide: MSWord files on CD

Introduction

Botany traditionally deals with the biology of plants, which can either be a general reference to all green, photosynthetically autotropic organisms or restricted to members of the Plant Kingdom, whatever that may include. Traditionally the study of fungi and bacteria were considered botany as well. Phylogenetic studies now place photosynthetic autotrophs in several different lineages, eubacteria (cyanobacteria, sulfur bacteria), alveolates (ciliated protists), stramenopiles (brown algae, diatoms, and chrysophytes), red algae, and the plants consisting of green algae and embryophytes (land plants). The general phylogenetic relationships of living organisms will be reviewed to place these organisms in context.

The purpose of this course is to reconstruct the evolutionary history of plant diversity by comparing the changing forms and structures of the vegetative and reproductive organs of both living and fossil organisms, all to help us understand why plant diversity is as it is, and why present day plants look and reproduce as they do. Land plants have left an impressive fossil record, and as a result, their history can be studied in some detail. Some groups are known only as fossils, others have a long history, some waxing, some waning, some lasting until the present day. For the longest part of Earth history, only prokaryotic organisms existed. Even after the appearance of eukaryotic organisms living organisms remained largely unicellular. Large multicellular organisms only became common in the late Precambrian. After the invasion of land, there have been four main periods of plant life, (1) the Devonian period of diversification and adaptation to land, (2) the Carboniferous coal swamps dominated by Clubmosses and Horsetails, (3) a period almost coincident with the age of reptiles and dinosaurs was dominated by gymnosperms and ferns, and (4) even before the dinosaurs became extinct, flowering/fruiting plants had become the dominant vegetation largely replacing gymnosperms.

Presently, seed plants, both gymnosperms and angiosperms, form the dominant terrestrial flora, and because of their dominance ecologically and their economic importance, they are the primary subjects of most botany courses. This course will attempt to place the success of seed plants in an evolutionary and ecological perspective. The reproductive adaptations of these plants cannot be understood without examining their historical origins. Flowers and fruits only make sense when placed in a historical context. Major evolutionary events in plant history (origin of the land plant life cycle, invasion of land, coal swamp vegetation, origin of leaves, origin of the pollen/seed habit) will be topics of more detailed discussions.

Objectives

1. To survey plant diversity including fossil groups.

2. To examine the major evolutionary events in the history of land plants and determine how the present floras, and present plant forms evolved.

3. To compare fossil and living plant forms in relation to their evolutionary history.

4. To understand the history of present day plant diversity and the highly modified reproductive and vegetative morphology of seed plants.

5. To learn and understand the reproduction of all plants.

Lecture Topics

I. Introduction Chapt. 1 & Chapt. 2

A. A Green World

1. How life works

2. Why green?

3. What is a plant?

B. Phylogeny of life

1. Lineages & common ancestries

2. Origin of photosynthetic autotrophy

3. Photosynthetic prokaryotes

C. Phylogeny and Classification

1. Brief history

2. Hierarchies & categories

3. Phylogenies and cladograms

D. Major historical events related to green organisms

1. Geological Time Scale & major events

2. Early life & the Archean environment

3. Fossils

4. Oxygen crisis & origin of eukaryotes Chapt. 3

II. Algae

A. The oceanic environment and phytoplankton Chapt. 4

B. The coastal environment and seaweeds Chapt. 5

C. Phytoplankton diversity

D. Seaweed diversity

E. Ancestors of land plants

III. The great invasion: how the land turn green Chapt. 6

A. Evidence

B. Hypotheses

1. Closest relatives of land plants

2. Origin of land plant life cycle

3. Relationships among land plants

IV. The bryophytic condition - nonvascular land plants Chapt. 7

A. Anthocerophyta - hornworts

B. Hepatophyta - liverworts

C. Bryophyta - mosses

D. Adaptations and limitations of the bryophytic condition

V. Vascular Plants

A. Early vascular plants Chapt. 8

1. Devonian diversity

2. Adaptive radiation - major lineages

B. Evolutionary trends in vascular plants

1. Vegetative features

a. Dichotomous vs. monopodial branching

b. Origin of leaves: microphylls and megaphylls

2. Reproductive adaptations

a. Homospory and heterospory

b. Stobili and sporophylls

C. Free-sporing Vascular Plants

1. The Clubmoss lineage

2. The Pteridophytes

a. Horsetails

b. Whiskferns

c. Ferns

D. Origin of the Seed Habit Chapt. 9

1. Pollen and Ovules: What are they really?

2. Progymnosperms: a missing link found!

E. The gymnospermous habit

1. Cycadophyta - cycads

2. Pinophyta

a. Pinales (Conifers)

b. Ginkgoales (Ginkgo)

c. Taxales - yews

3. Gnetophyta

4. Fossil gymnosperms and angiosperm ancestry

F. Angiosperms - Flowering/fruiting plants Chapt. 10

1. Geological history - Why so successful so fast?

2. Morphological trends - pollinators and dispersers

3. Origins of modern vegetation

4. Outline of taxonomic and character diversity

5. Our understanding of reproductive modifications

EXAMS

There will be 4 exams given during the semester, including the final exam. Certain aspects of the subject matter will be considered comprehensive, and questions on subsequent exams may require you to draw upon material covered on previous exams. Up to 20% of each exam may be based upon corresponding laboratory material. Exams will consist of one or more learning summaries that will be assigned one week before the in class exam. Learning summaries are prepared prior to the exam and turned in with the rest of the exam. Learning summaries may account for up to 40% of the exam credits. A description of learning summaries follows. The exams will be a percentage of the total points with all exams receiving equal weight. A general A = >85, B = 75-84, C = 65-74, D = 55-64, F = <55 grade scale will be employed.

LEARNING SUMMARIES

Learning summaries differ from essay questions on exams in significant ways. A learning summary consists of a detailed explanation of your understanding of a particular question, concept, or topic wherein you demonstrate your mastery of the material by using and interrelating new vocabulary, new information, and new ideas correctly. Unlike essay exams you are under no strict time constraints, and you will have available your notes, textbook, and other materials. Each summary is limited to no more than 1-2 standard typed pages because length is not a good measure of quality or effort. You are expected to exhibit college-level communication skills, proper grammar, and correct spelling. To assist you in writing, a list of easy to remember grammar rules will be provided.

Although you are encouraged to work in groups, discuss ideas, and study in groups, learning summaries must be written individually. To copy or use another student's work for your own is a form of plagiarism. In its most serious and flagrant form plagiarism can end your academic career at ISU. High degrees of similarity in sentences and phrasings do not happen by chance, by studying together, or by being genetically identical (The twin excuse; yes, I’ve heard the claim, and tested it. Twins failed to produce any similarities under controlled circumstances.); they are evidence of plagiarism. Finally, do not allow a fellow student to copy your work, otherwise you risk being an accessory to academic dishonesty. Stop and consider this. If a faculty member finds two nearly identical answers they have no way of knowing which is the original and which is the copy. Since I am a trained observer, few if any such similarities will escape my attention.

LABORATORY

The laboratory portion of this course is designed to familiarize you with the green organisms. Although the lecture and lab are parallel, they cover material at different rates such that the laboratory is ahead of lecture almost throughout the semester. Each laboratory you will receive a guide to observations that includes a list of all the materials and specimens. These include living organisms, preserved specimens, herbarium specimens (pressed and dried), slides, and fossils. You should expect that additional observational time will be required to master the laboratory materials. The laboratory classroom will be available to you on Fridays.

You will develop and organize a complete and well-organized laboratory notebook in digital form consisting of digital images and written descriptions of your observations, augmented by downloaded internet images. Detailed instructions for constructing your laboratory notebook will be provided. This notebook will receive an evaluation equivalent to 20% of the final course grade. Quality notebooks are considered evidence of quality observations; their detail and completeness are measures of your effort and industriousness.

LABORATORY SCHEDULE

Week 1, Jan. 18 – LITTLE WILD GREEN THINGS

Week 2, Jan. 25 – SURVEY OF ALGAE

Week 3, Feb. 1 – SURVEY OF ALGAE

Week 4, Feb. 8 – BRYOPHYTES I

Week 5, Feb. 15 – BRYOPHYTES II

Week 6, Feb. 22 – CLUBMOSSES I *

Week 7, Mar. 1 – CLUBMOSSES II *

Week 8, Mar. 8 – HORSETAILS & WHISKFERNS *

SPRING BREAK

Week 9, Mar. 22 – FERNS I *

Week 10, Mar. 29 – FERNS II *

Week 11, Apr. 5 – GYMNOSPERMS I (CONIFERS & GINKGO) *

Week 12, Apr. 12 – GYMNOSPERMS II (CYCADS & GNETALES)

Week 13, Apr. 19 – ANGIOSPERMS I (GENERAL STRUCTURE)

Week 14, Apr. 26 – ANGIOSPERMS II (REPRODUCTION)

Week 15, May 3 – ANGIOSPERMS III (ADAPTATIONS)

* Indicates fossil specimens are included.

OBSERVATION - THE BASIS OF SCIENCE

What is observation?

All of science is based on observation, which includes all of the information, data, humans can collect with our senses and our instruments. Hypotheses are ultimately the result of trying to explain prior observations. Biology students must observe specimens (1) to help explain to themselves viable biological hypotheses, and (2) to develop a familiarity and conceptual understanding of diverse organisms. Ideas must be firmly linked to mental images, and many images must be interrelated and compared. This is no small task. Your notebook should assist you in this integration.

Observation is a skill, and like all skills, it takes practice to improve. It should be apparent to you that it takes both talent and practice to develop a high level of skill and proficiency in sports. Only relatively good high school athletes play sports at a colleagiate level, and then only with a lot more coaching and practice. College athletes practice for hours daily often working on conditioning and special skills. Very few athletes with college-level skills actually reach professional levels, and it took a lot of work, coaching, and practice to reach a professional skill level. Why should biology be any different? A similar effort is necessary to develop college-level and professional-level academic skills. Lastly does anyone actually think an academic subject like biology is easier to master intellectually than a sport is to master physically? The laboratory is your practice field, and your instructors are your coaches, and we determine if you have what it takes to make the team.

Observation takes time, effort, and patience, and lower level skills result in inefficiency and more time is needed to obtain similar results. You may have developed the habit of using superficial "looking" in place of observation, just checking to see if the specimen looks like the diagram, and then, zip, on to the next. Students who rush through laboratory work, spending a minimum amount of time, are not demonstrating any commitment to improving and reaching a higher skills level.

The laboratory guide for BSC 222 was written to assist you in developing better observational skills. The sequence of specimens, the written instructions and descriptions, and the questions posed should direct your thinking and observations.

Developing Context

There will be a great variety of specimens to observe from living, to preserved, to fossil, to sectioned specimens, and it is difficult to keep individual observations of parts and individual structures in the context of the whole organism. ALL series of observations must begin with whole specimens to determine when and where other specimens come from. You must work back and forth from gross observation to a dissecting scope to a compound microscope and back. If you cannot place an image from a microscopic specimen accurately and precisely upon a gross specimen, then you are not developing conceptual knowledge. Your instructor will insist that you be able to make such a determination at all times.

Consider a pile of bricks. Bricks are good materials, and it is good to have lots of them, but to really be useful, bricks must be organized into an ediface of some sort. A bunch of images and files are just like a pile of bricks, it is good to have lots of them, but they are much more meaningful if organized and put into proper context. For example, images of microscopic structures can be organized by linking them to some part of an organism or lower magnification image. All images must have significant features labelled. Image mapping is a technique that can be very useful in this regard.

Slide labels are frequently incorrect or misleading, often using colloquial or ancient terms. Slide labels only refer to the most prominent feature that can be observed, rather than delimiting what is actually on the slide. Good observers decide for themselves what is on a slide. For example a slide label reads "Lily - 8-nucleate embryo sac". This means the specimen shows, somewhere, a female gametophyte of a lily, which are located within an ovule inside the ovary at the center of a lily flower. The slide manufacturers know this and simply made cross sections of an entire lily flower bud expecting that you will (1) think about what you wish to observe, (2) decide where to seek it, and (3) then find the appropriate part. When a student accurately draws the entire cross-sectioned flower at low power and labels it "8-nucleate embryo sac", the instructor knows they actually observed exactly nothing and thought exactly nothing.

When there are 2 or more sections on a slide they are in serial order, i.e., they represent adjacent slices of the specimen, just like slices of bread in the loaf. However these slices are so thin, an average piece of paper might be 5-10 times as thick. Features may not be completely in one section so always look at adjacent sections. Larger features may have to be observed in adjacent sections to observe the whole thing, just as a large air hole may take several slices of bread to figure out the whole hole. Make a practice of moving back and forth between sections to make certain you have seen all of a feature or the best representation.

RULES ABOUT DIGITAL IMAGES

Digital cameras can be used to capture images. You must capture your own images. Sharing images is a form of plagiarism. Any downloaded images must indicate their source.

RULES OF HANDLING SLIDES

1. Before you observe a specimen on a slide, you must know what you are looking for and where, in the context of the whole organism, the specimen comes from. So think before you observe.

2. Slides should only be handled by the edges and label end. Since generations of prior students ignored this rule, their grimy, sticky, kiddy finger prints cover the slides. Each slide will be cleaned using a spritz of glass cleaner and gently buffed dry using Utility Paper, which comes in a perforatred role and looks just like TP. Remember, dirt just isn't very interesting. Once cleaned any finger prints that appear will be traced to their owner!

3. Slides should be handled individually, with care. Slides should not be stacked. Whole mount slides are the most fragile and should be handled with extreme care. Thick whole mounts may only be observed using the short, low-power objectives. Slides cost $2-10 each.

4. Take care to return the slide to the proper tray or box.

Handling Fossils

Fossils are rocks, but they are still fragile, and RARE! Handle fossils with care. Cellulose acetate peels are particularly fragile. Handle them only by their attached file card.