Station 21 – Classification

Biology 2: LAB PRACTICUM 1

Biology 2

Lab Packet

For

Practical 1

1


CLASSIFICATION :

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Domain: Bacteria

Group: Proteobacteria

Group: Gram-positive Bacteria

Group: Cyanobacteria

Group: Spirochetes

Group: Chlamydias

Domain: Archaea

Group: Methanogens

Group: Halophiles

Group: Thermophiles

Viruses

INTRODUCTION FOR THE PROKARYOTES (Domains Bacteria and Archaea)

The domain Bacteria contains more than 4500 species of bacteria that have been characterized and many more exist. Bacteria are the most widespread organisms in the world. All of these organisms are made up of single prokaryotic cells although some will aggregate into groups or form colonies. Their genetic material (a single chromosome made up of DNA) is concentrated in a nucleoid region but has no nuclear membrane that separates this region from the rest of the cytosol. They also lack membrane-bound organelles. Bacteria range in size between 1 u m – 10 u m in size. This domain is usually broken up into a dozen groups based on sequences of ribosomal RNA, shape [ cocci (spherical), bacilli (rod-shaped), helices (spiral), and filaments ], nutritional mode ( photoautotrophs, chemoautotrophs, photoheterotrophs, and chemoheterotrophs ), and the cell wall’s ability to gram-stain .

The domain Archaea contains prokaryotic cells that usually inhabit the more extreme environments on

Earth such as swamps and marshes without oxygen, extremely saline (salty) waters and extremely hot sulfur springs. These organisms have been separated from the other prokaryotic cells because of signature sequences in their ribosomal RNA and their nucleic acids.

Station 1 – Prokaryotic Cells

Know the following drawing with the correct names. (Figure 6.6, p 98 from Campbell & Reece)

Biology 2: LAB PRACTICUM 1 3

Station 2 – Bacterial Shapes

Be able to identify the shape cocci . Use the slide of Streptococcus lactis (in a chain) to become familiar with this shape.

Streptococcus lactis ( P 28, Fig 3.8 – similar appearance to Neisseria gonorrhoeae )


Be able to identify the shape bacillus . Use the slide of Clostridium tetani (with endospores) to become familiar with this shape.

Clostridium tetani ( P 28, Fig 3.4 – similar appearance to Bacillus megaterium )


Be able to identify the shape spirillum . Use the slide of Spirillum volutans (with flagella) to become familiar with this shape.

Spirillum volutans ( P 28, Fig 3.6 – Borella Recurrentis similar appearance to S. volutans )


Be able to identify the shape filamentous . Use the slide of Oscillatoria to become familiar with this shape. You will be held responsible for both the fixed and live slides.

Oscillatoria filaments ( P 31, Fig. 3.21)


Station 6 – Bacterial Colonies

When growing on a nutrient medium which has been hardened with agar (a derivative of red algae), each species of bacteria will form a characteristic colony that can be identified. A colony is a cluster of millions of bacteria. Observe the Petri dishes that have been contaminated with bacteria. Note the colonies vary in size, shape and color. They usually have a smooth or glossy surface, unlike mold (fungi) colonies, which have a fluffy, cottony, or filamentous appearance. Their height, edges or color may identify colonies. Be able to recognize that these are bacterial colonies.

You will not be asked to know the different terms on the station card (round, wavy, wrinkled, etc.) or the type of bacteria colony.

Station 7 – Bacteria and Antibiotics

Observe the Petri dishes that contain antibiotic discs. Antibiotics are used to treat infections because they inhibit growth of the bacterial colony. Each disc contains a different antibiotic. A clear area denotes the inhibition of bacterial growth. (No figures available) – You will not be asked to recognize any specific antibiotic and how it works on any specific bacteria.

1.

What characteristics allow antibiotics to work on bacterial cells but do not affect eukaryotic cells?

2.

Do the same antibiotics work differently on different colonies of bacteria?

3. How does this affect the use of antibiotics to fight disease?

4.

What is a narrow spectrum antibiotic?

5.

What is a broad spectrum antibiotic?


Station 8 – Bacterial Pigments

1.

What are the reasons that some bacteria are pigmented?

2. Be able to recognize the pigmented bacteria located at this station.

Station 9 – Luminescent Bacteria

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1.

Where can luminescent bacteria be found?

2.

What enzyme do these species have that allows them to give off light?

3.

What industrial application do these bacteria serve?

Station 10 – Gram Stain (Gram Positive and Gram Negative)

Be able to recognize the difference between a slide that is gram-positive and one that is gram-negative.

1.

What is the structure of the cell wall in gram-positive bacteria?

2.

What color are the bacteria when stained if it is gram positive?

3.

What is the structure of the cell wall in gram-negative bacteria?

4.

What color are the bacteria when stained if it is gram-negative?


Station 11 – Classification

Domain: Bacteria Group: Proteobacteria

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1.

How is this group divided into subgroups?

2.

Be able to answer the following questions about the example E. coli (You will not be asked to identify E.

coli by sight) a) Is E. coli gram-positive or gram-negative? b) What are the oxygen requirements of E. coli ? c) What shape does E. coli demonstrate? d) Where can E. coli be found? e) What structure do some of the pathogenic strains have? f) What are the causes of outbreaks of E. coli in the United States?


Domain: Bacteria Group: Gram-positive bacteria

1.

What type of gram stain do most of the bacteria in this group demonstrate?

2.

What are the nutritional requirements for most of the bacteria in this group?

3.

Be able to recognize the example of Clostridium tetani a) Is Clostridium gram-positive or gram-negative? b) What are the oxygen requirements of Clostridium ? c) What shape does Clostridium demonstrate? d) Where can Clostridium be found? e) What is the function of the endospore? f) What type of toxin does Clostridium release? g) What disease does Clostridium tetani cause?



Domain: Bacteria Group: Cyanobacteria

1.

What are the nutritional requirements for most of the bacteria in this group?

2.

What are the oxygen requirements for the bacteria in this group?

3.

What is the name of the pigment that gives the bacteria in this group their blue-green color?

4.

What are the two processes that are only found together in this group of organisms?

5.

Be able to recognize the prepared and live examples of Oscillatoria ( P 31, Fig. 3.21) a) Where can Oscillatoria be found? b) What shape does Oscillatoria demonstrate? c) What causes Oscillatoria to go through a “bloom”? d) What is the eventual outcome of these “blooms”?


Domain: Bacteria Group: Spirochetes

1.

What shape do these organisms demonstrate?

2.

What are the nutritional requirements for this organism?

3.

What is the name of the special structure involved in this group’s movement?

4.

Be able to recognize the example Treponema pallidum ( P 28, Fig. 3.7

) a) What disease does Treponema pallidum cause? b) What are the four stages and symptoms of this disease?

Stage 3 - Stage 1 -

Stage 2 - Stage 4 - c) How is this disease transmitted and what are the requirements for transmission? d) What is the oxygen requirement for Treponema pallidum ?

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Domain: Bacteria Group: Chlamydias

1.

What shape do these organisms demonstrate?

2.

Where are these organisms found?

3.

How are these organisms transmitted?

4.

Is this group Gram-positive or Gram-negative?

5.

What is lacking in the cell wall of this group?

6.

Why don’t we have an example of this group?

7.

Know the example Chlamydia trachomatis ( No figure available ) a) What two problems does Chlamydia trachomatis cause?

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Domain: Archaea

1.

What are the three groups in this domain and how are they separated?

2.

What types of cells make up these organisms?

3.

What characteristics do these organisms have in common with eukaryotes?

4.

What are these organisms most closely related to?

5.

Know the example slide for this domain ( No figure available – You will not be asked to identify Archaea by sight )


Station 17 – Viruses

1.

What are viruses made up of? What are the 6 different forms of nucleic acid found in viruses?

2.

What size are they?

3.

How do viruses reproduce? What are the two cycles? How do they differ?

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CLASSIFICATION :

Domain: Eukarya

Supergroup: Excavata

Clade: Diplomonads

Clade: Parabasalids

Clade: Euglenozoans

Group: Euglenids

Group: Kinetoplastids

Supergroup: Chromalveolata

Clade: Alveolates

Group: Dinoflagellates

Group: Apicomplexans

Group: Ciliates

Clade: Stramenopila

Group: Bacillariophyta

Group: Chrysophyta

Group: Phaeophyta

Group: Oomycota

INTRODUCTION FOR PROTISTA

The kingdom Protista (in the five kingdom system) contains mostly unicellular eukaryotes.

This taxonomic grouping is polyphyletic and based only on cellular structure and life styles not on any molecular evidence. Using molecular biology and detailed comparison of cell structure, scientists are now beginning to see evolutionary history in the protists. The ongoing changes in the protest phylogeny are rapidly changing with each new piece of evidence. The following classification suggests 5 “supergroups” within the original protista kingdom and the taxonomy is still being worked out. This lab is looking at one current hypothesis shown on the right. Some of the organisms are grouped together because of very strong support and others are controversial. It is important to focus on the characteristics of each clade which explains why they are grouped together. This lab will only look at the groups that were once included in the Protista kingdom and the other groups

(higher plants, fungi, and animals) will be examined in future labs.

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Supergroup: Rhizaria

Group: Chlorachinophytes

Group: Foraminiferans

Group: Radiolarians

Supergroup: Archaeplastida

Group: Rhodophyta

Group: Chlorophyta

Supergroup: Unikonta

Clade: Amoebozoans

Group: Slime Molds (Plasmodial / Cellular)

Group: Gymnamoebas

Group: Entamoebas

Clade: Opisthokonts

Group: Nucleariids

Group: Choanoflagellates


Station 1 - Classification

Supergroup: Excavata Clade: Diplomonads

1.

What characteristics are responsible for placing this organism in the Supergroup: Excavata?

2.

What characteristics are specific to Diplomonads?

3.

Be able to recognize the example Giardia lamblia. a) Where is this organism found? b) What are the symptoms caused by this organism?


Supergroup: Excavata Clade: Parabasalids

1.


2.

What characteristics are specific to Parabasalids?

3.

Be able to recognize the example Trichomonas vaginalis . (P 38, Fig. 4.23) a) What does this organism cause? b) How is this organism transmitted?

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Supergroup: Excavata Clade: Euglenozoans Group: Euglenids

1.


2.

What characteristics do all Euglenozoans have?

3.

What characteristics are specific to Euglenids?

4.

Be able to recognize the example Euglena. (P 38, fig 4.26-4.28) a) Where is this organism found? b) Are the flagella on the anterior or posterior end? c) Know the structures on the figure.


Supergroup: Excavata Clade: Euglenozoans Group: Kinetoplastids

1.


2.

What characteristics do all Euglenozoans have?

3.

What characteristics are specific to Kinetoplastids?

4.

Be able to recognize the example Trypanosoma. (P 38, Fig. 4.25) a) What does this organism cause? b) How is this organism transmitted?

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Supergroup: Chromalveolata Clade: Alveolates Group: Dinoflagellates

1.

What characteristics are responsible for placing this organism in the Supergroup: Chromalveolata?

2.

What characteristics do all Alveolates have?

3.

What characteristics are specific to Dinoflagellates?

4.

Be able to recognize the example as a Dinoflagellate ( Peridinium) . (P 36, Fig. 4.15 & 4.17) a) What does this organism cause? b) What does this organism release?


Supergroup: Chromalveolata Clade: Alveolates Group: Apicomplexans

1.


2.


3.

What characteristics are specific to Apicomplexans?

4.

Be able to recognize the example Plasmodium (P 37, Fig. 4.22) a) What does this organism cause? b) How is this organism transmitted? c) What parts of the human does this organism attack?

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Supergroup: Chromalveolata Clade: Alveolates Group: Ciliates

1.


2.


3.

What characteristics are specific to Ciliates?

4.

Be able to recognize the examples Spirostomum, Vorticella, Paramecium .

Spirostomum

Station 8 – Ciliate Reproduction

Vorticella

1.

Use the example Paramecium to demonstrate how Ciliates can reproduce. a) Be able to recognize the example of transverse binary fission. (P 39, Fig. 4.32)

1.

Is it asexual or genetic recombination? b) Be able to recognize conjugation. (P 39, Fig. 4.33)

1.

Is it asexual or genetic recombination?

2.

Which nuclei are exchanged?

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Supergroup: Chromalveolata Clade: Stramenopila Group: Bacillariophyta

1.


2.

What characteristics do all Stramenopila have?

3.

What characteristics are specific to Bacillariophyta?

4.

Be able to recognize the example Diatoms (P 33-34, Figs. 4.1 - 4.10) . a) How is this organism used?


Supergroup: Chromalveolata Clade: Stramenopila Group: Chrysophyta

1.


2.


3.

What characteristics are specific to Chrysophyta?

4.

Be able to recognize the example Vaucheria .

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Supergroup: Chromalveolata Clade: Stramenopila Group: Phaeophyta

1.


2.


3.

What characteristics are specific to Phaeophyta?

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4.

Be able to recognize the examples in the jars ( Fucus, Laminaria, Sargassum ) (P 51-53, Fig. 4.85-4.93)


Supergroup: Chromalveolata Clade: Stramenopila Group: Oomycota

1.


2.


3.

What characteristics are specific to Oomycota?

4.

Know the example Saprolegnia . (P 61, P 62 Fig. 4.121-4.125) a) What two major agriculture problems has it caused?

5.

What characteristics does it have in common with protista?

6.

What characteristics does it have in common with fungi?


Station 13 – Fucus Structures

3.

Be sure you can identify these structures: holdfast, stipe, blades, airbladders, receptacles, and ostioles .

Fucus preserved specimen

(P 55, Fig. 4.95)

4.

The brown algae “plant” looking specimen in the fingerbowl belongs to which generation? (haploid or diploid) (P 54, Fig. 4.94)

Station 14 – Fucus internal structures

1.

Observe both the male and female conceptacles, which are available on prepared slides. In the male, find the branched antheridia and the sperm . Surrounding the antheridia, there are sterile hairs called paraphyses , which are used for protection. In the female, observe the oogonia and their eggs along with the paraphyses .

Antheridium (slide)

(P 55, Fig. 4.90-4.92)

Oogonia (slide)

(P 55, Fig. 4.93-4.94)


Station 15– Classification

Supergroup: Rhizaria Group: Radiolarians

1.

What characteristics are responsible for placing this organism in the Supergroup: Rhizaria?

2.

What characteristics are specific to Radiolarians?

3.

Know the example Radiolarian strew. a) Where do these organisms live? b) What are their tests made of?


Supergroup: Rhizaria Group: Foraminiferans

1.

What characteristics are responsible for placing this organism in the Supergroup: Rhizaria?

2.

What characteristics are specific to Foraminiferans?

3.

Know the example of Foraminiferans a) Where do these organisms live? b) What are their tests made of?

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Supergroup: Archaeplastida Group: Rhodophyta

1.

What characteristics are responsible for placing this organism in the Supergroup: Archaeplastida?

2.

What characteristics do all red algae (Rhodophyta) have?

3.

Know the example Rhodophyta: Corallina , Chondrus . (P 57) a) Where do these organisms live? b) How do they disperse their gametes? c) Are these algae structures seen in the jars haploid, diploid or something else?

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Supergroup: Archaeplastida Group: Chlorophyta

1.

What characteristics are responsible for placing this organism in the Supergroup: Archaeplastida?

2.

What characteristics do all green algae have?

3.

What kind of cellular forms are seen in this group?

4.

Know the following examples Chlorophyta: Chara, Acetabularia, Ulva, Cladophora

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Supergroup: Archaeplastids Group: Chlorophyta Ex: Desmids (P 49, Fig. 4.70-4.73)

1.

Where are desmids found?

2.

Be able to identify the following structures: nucleus, isthmus, and chloroplasts .


Supergroup: Archaeplastids Group: Chlorophyta

1.

What type of cellular form do they exhibit?

Ex: Volvox (P 42, Figs. 4.43 – 4.44)

2.

Be able to identify the following structures: vegetative cells, protoplasmic strands, and daughter colonies .



Supergroup: Archaeplastids Group: Chlorophyta Ex: Protococcus

1.


2.

Where is this organism found?

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1.


Ex: Spirogyra

2.

Be able to identify the chloroplasts, nucleus, conjugation tube, male gamete, female gamete, and

Zygospore .

3.

What part of the life cycle is haploid and which are diploid?

4.

Why are the gametes in the species referred to as isogametes?

Spirogyra filaments

(P 46, Fig. 4.61)

Conjugation Tubes

(P 47, Fig. 4.62)




1.

What structure demonstrates specialization?

2.

Be able to identify the chloroplasts.

3.

Are the filaments haploid or diploid?

Ulothrix

(P 43, Fig. 4.49 & P 44, Fig 4.50)

Ex: Ulothrix

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Supergroup: Unikonta Clade: Amoebozoans Group: Gymnamoebas

1.

What characteristics are responsible for placing this organism in the Supergroup: Unikonta?

2.

What characteristics do all Amoebozoans have in common?

3.

What characteristics are specific to Gymnamoebas?

4.

Know the example Amoeba ( P. 37, figs. 4.18 & 4.19

). a) Where do these organisms live? b) How are parasitic Gymnamoebas passed?

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Supergroup: Unikonta Clade: Amoebozoans Group: Entamoebas

1.


2.

What characteristics do all Amoebozoans have in common?

3.

What characteristics are specific to Entamoebas?

4.

Know the example Entamoeba histolytica ( P. 37, Fig. 4.21) a) How many species are found in humans? b) Which is the only one that is pathogenic in humans? c) What are the symptoms caused by this species and how many deaths occur worldwide each year?



Supergroup: Unikonta Clade: Amoebozoans Group: Plasmodial Slime Molds

1.


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2.

What characteristics do all Slime molds have?

3.

Know the example Physareum (P 59, Fig 4.107). a) Are the hyphae coenocytic or septate? b) Why do these organisms group together?


Supergroup: Unikonta Clade: Amoebozoans Group: Cellular Slime Molds

1.


2.

What characteristics do all the Slime molds have?

3.

Know the example Dictyostelium (No figure available). a) Are the hyphae coenocytic or septate? b) Why do these organisms group together?



Supergroup: Unikonta Clade: Opisthokonts Group: Nucleariids

1.


2.

What characteristics do all Opisthokonts have?

3.

What characteristics are specific to Nucleariids?


Supergroup: Unikonta Clade: Opisthokonts Group: Choanoflagellates

1.


2.

What characteristics do all the Opisthokonts have?

3.

What characteristics are specific to Choanoflagellates?

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FUNGI AND SEEDLESS PLANTS

CLASSIFICATION:

Domain: Eukarya

Kingdom: Fungi

( Clade: Opisthokonts)

Division: Chytridomycota - Chytrids

Division: Zygomycota - Coenocytic Fungi

Division: Glomeromycota - Arbuscular Mycorrhizae

Division: Ascomycota - Sac Fungi

Division: Basidiomycota - Club Fungi

Division: Deuteromycota – Imperfect Fungi

Symbiotic relationships: Lichen

Kingdom: Plantae

Nonvascular Seedless Plants

Division: Hepatophyta - Liverworts

Division: Bryophyta - Mosses

Vascular Seedless Plants

Division: Lycophyta - Club Mosses

Division: Pterophyta

(Psilophyta) - Whisk ferns

(Sphenophyta) - Horsetails

(Pterophyta) - Ferns

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INTRODUCTION FOR FUNGI

Fungi are multicellular eukaryotes . All fungi are heterotrophs and acquire their nutrients by absorption .

Foods are digested outside the organism by enzymes released by the fungi and than the nutrients are absorbed.

Lacking chlorophyll, these organisms are entirely dependent upon organic matter. Most fungi derive their nutrients from dead organic compounds (saprobes or decomposers) , but some draw their nourishment from living plant or animal material (parasites) .

Reproduction is both sexual and asexual and all fungi produce spores . There are more than 100,000 species of fungi known and many that have yet to be identified. They are placed in the clade Opisthokonts due to the posterior location of the flagellum in some fungi.

The basic structure of most fungi is usually hidden under ground. These bodies are constructed of hyphae

(minute threads) which form a mat called a mycelium (the feeding structure of a fungus).

Station 1 – Division: Chytridomycota – Chytrids

The chytrids are thought to be the most primitive type of fungi and a link between protists and fungi.

Most are aquatic but some are saprobes and others are parasitic on protists, plants, and aquatic invertebrates.

They have coenocytic hyphae if they are multicellular.

1.

What do these organisms have in common with “protists”?

2. What do these organisms have in common with fungi?

No Example Available for the Chytrids


Station 2 - Division: Zygomycota – Coenocytic Fungi

The fungi that have aseptate hyphae (lacking septa or crosswalls) are placed in this division. They are also called coenocytic because they have many nuclei per hyphae. These fungi are mostly terrestrial and live in soil. A common zygomycete is black bread mold (Rhizopus nigricans) .

Rhizopus : Observe the petri dish (under a dissecting microscope) of the living culture Rhizopus growing on agar. The white hairs are the hyphae that make up the mycelium. The black objects are sporangia , containing the asexually produced spores. The special hyphae bearing the sporangia are called sporagiophores . Hyphae that travel horizontally along the agar are called stolons.

The structures that travel downward are called rhizoids . Be able to identify the following structures: hyphae, mycelium, sporangia, sporangiophores.

Also be able to distinguish Rhizopus from the bacterial plates and the other fungi.

Rhizopus Petri Plate

(P 65, Figs. 5.3 – 5.8)

Rhizopus Sporangia Slide


Station 3 – Genetic Reproduction of Rhizopus

1.

What is the name of the process for Genetic Reproduction in Rhizopus ?

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2.

What is the term used for fusion of the cytoplasm?

3.

What is the term used when a cell has two nuclei?

4.

What is the term used when the nuclei fuse together?

Conjugation occurs when two strains grow close together. Each mycelium grows projections, called progametes . The cell develops a rough, thick wall that can protect the nucleus from harsh conditions. This structure is called a zygospore . Observe a slide of Rhizopus conjugating. Be able to identify the following structures: progametes and zygospore .

(P 65, Fig 5.8)

Station 4 - Division: Glomeromycota - Arbuscular Mycorrhizae

These individuals were once thought to be part of the zygomycota but molecular evidence suggests that these species should be part of their own clade.

1.

What are arbuscules?

2.

What percentage of plant species have symbiotic relationships with these fungi?

No Example Available for the Mycorrhizae


Station 5 Division: Ascomycota - Sac Fungi

One of the fungi with septate fungi is the Sac or Cup Fungi. They are called septate because they usually have one or two nuclei per cell. They are usually saprobes or mutualistic. Be able to recognize the preserved specimens of Peziza.

(P. 66, Fig. 5.9)

1.

What are the characteristics of Sac Fungi?

2. What type of hyphae makes up an ascocarp?

Station 6 – Division: Ascomycota – Sexual Reproduction

Be able to identify the following structures of a cross section through an ascocarp: hyphae, mycelium, hymenial layer, asci, and ascospores.

Sexual Reproduction

(P 68, Figs. 5.16)


Station 7 - Division: Basidiomycota - Club Fungi

Examine living or preserved specimens of whole mushrooms. . This division includes mushrooms, toadstools, shelf fungi, and puffballs, smuts and rusts. Be able to identify the following structures : cap, annulus, gills and stipe.

1.

What are the characteristics of club fungi?

2.

What type of hyphae makes up a basidiocarp ?

Mushroom (Basidiocarp)

(P 70-72, Fig 5.25-5.29)


Station 8 – Division: Basidiomycota – Sexual Reproduction

Examine a prepared slide of Coprinus , which shows a longitudinal cross section through a basidiocarp.

Be able to identify the following structures: hyphae, mycelium, hymenial layer, basidia, and basidiospores.

Sexual Reproduction

(P 72, Fig. 5.30)

Station 9 – Division: Deuteromycota – Imperfect Fungi

Examine living cultures of Penicillum notatum and Aspergillus niger in the petri dishes. Note the coloring and texture of each culture. Be sure you are able to tell these apart from other cultures seen earlier.

1.

Why are these fungi considered to be imperfect?

Penicillum notatum

(P 69, Figs. 5.20)

Station 10 – Division: Deuteromycota – Imperfect Fungi

Aspergillus niger

(P 69, Fig. 5.21-5.24)

Examine a prepared slide of the spore-bearing conidiophores, which house conidia. Spores of

Penicillum appear blue-green and resemble a “kitchen fork”. Spores of Aspergillus appear black and resemble an “afro” hairstyle. Be able to identify the following structures: condiophores and conidia

Penicillum notatum

(P 69, Figs. 5.20)

Station 11 – Lichen (P 75, Fig. 5.39)

Examine various lichens externally.

Aspergillus niger

(P 69, Fig. 5.23)

1.

What two organisms make up the symbiotic relationship found in lichens?

2. What does each organism bring to the relationship?


INTRODUCTION

The kingdom Plantae includes about twelve divisions. They are placed in the clade Arcaeplastida along with the green algae .

They are all eukaryotic and multicellular with distinct cell walls . Photosynthetic pigments occur in organelles called plastids . Plants have adapted to the terrestrial environment with an increase in structural complexity. Many plants have developed organs for anchorage, conduction, support, and photosynthesis. Reproduction is primarily sexual, with an alternation of generation of haploid and diploid generations. The sporophyte generation becomes increasingly predominant as plants evolve.

The nonvascular plants lack conductive tissue and are limited to a specific range of terrestrial habitats. These plants display two adaptations that first made the move onto land possible. They possess a waxy cuticle to reduce water loss and their gametes develop within gametangia for protection of the embryo. These plants are limited in range because they do require water for reproduction. They lack vascular tissue , which means they must live in moist environments. They also lack woody structures for support therefore they grow low to the ground.

Station 12 – Division: Bryophyta - Mosses

Examine the “leafy” moss plants provided for you. You need to be able to recognize this species as a moss.

1.

Is there a vein system present in the “leaves”?

2.

Is this “plant” a gametophyte or a sporophyte?


Station 13 – Division: Bryophyta – Protonema

Examine a prepared slide of a germinating spore. The germinating structure is called a protonema. This structure is very similar to some filamentous green algae and is one piece of evidence that mosses might have evolved from some form of green algae. Be able to recognize the following structures : protonema, buds.

Germinating Spores

(P 85, Fig. 6.33)

Station 14 – The Gametophyte Generation of a Moss

Male plants can be identified by the flower-like cluster of “leaves” at the tip of the gametophyte. In the female plants, the “leaves” closely surround the tip of the gametophyte

. Be able to recognize the difference between male and female plants.

Male Female

Station 15 - The Antheridium

Examine the prepared slides of longitudinal cross section of a male and female gametophyte tip. Locate the antheridium . Be able to identify the following structures: antheridium , paraphyses , sterile jacket cells , sperm.

Antheridial Disc

(P 86, Fig. 6.35-6.36)


Station 16 - The Archegonium

Examine the prepared slides of longitudinal cross section of a female gametophyte tip. Locate the archegonium . Be able to identify the following structures: archegonia , egg, venter, neck, and paraphyses.

Archegonial Disc

(P 86, Fig 6.34)

Station 17 - The Sporophyte Generation of a Moss

Examine a sporophyte generation of a moss under a dissecting scope. Be able to recognize the following structures: seta and capsule

1.

The sporophyte generation is attached to a gametophyte generation. What sex is the gametophyte?

Sporophyte

(P 85, Fig. 6.31-6.32)

Station 18 - The Sporophyte Generation of a Moss

Examine a prepared slide of a capsule. Be able to recognize the following structures: operculum , columella , and spores .

Sporophyte Capsule

( P86, Fig 6.38)


Station 19 - Division: Hepatophyta – Liverworts

Be able to recognize the example liverwort Marchantia . Examine preserved specimens of the liverwort thallus .

1.

How are the thallus flattened?

2. Is this “plant” a gametophyte or a sporophyte?

Station 20 – Liverwort Thallus

Examine a prepared slide showing a cross section of a Marchantia thallus. The thallus is divided into an upper and lower section. Be able to recognize the following structures : storage cells, photosynthetic cells, air pores, and air chambers .

1.

What is the function of the upper section of the thallus?

2.

What is the function of the lower section of the thallus?

3.

What is the difference between a rhizoid and a scale?

4.

What is the function of the air chambers surrounding the chlorophyll-bearing cells?

5.

What is the function of the rhizoids and scales?

Thallus

Station 21 –Antheridial and Archegonial Receptacles (Preserved)

Be able to recognize the antheridial and archegonial receptacles of a liverwort.

1.

What does the antheridia produce?

2.

What does the archegonia produce?

Male

(P 80, Fig. 6.6)

Female

(P 80, Fig. 6.7)


Station 22 – Antheridial and Archegonial Receptacles (Prepared Slides)

Study prepared slides of antheridial and archegonial discs. Be able to recognize the following structures: antheridia, sperm, archegonia, neck, egg, and venter.

Male

(P 81, Fig. 6.16)

Female

(P 81, Fig. 6.12)

Station 23 - The Sporophyte Generation of a Liverwort

The sporophyte generation is dependent on the gametophyte generation. Examine a prepared slide of a

Marchantia embryo. Be able to recognize the following structures: foot , seta , capsule , spores and elaters .

1.

What is the function of the elaters? How do they work?

2.

Is the sporophyte haploid or diploid?

3.

The sporophyte is attached to a gametophyte. What sex is the gametophyte?

Sporophyte

(P 81, Fig. 6.15)

Station 24 - Asexual Reproduction of a Liverwort

Examine a living gametophyte showing asexually reproductive gemmae cups . Be able to recognize a gametophyte showing the cups with gemmae inside.

1. How are the gemmae dispersed?

Gemmae Cups

(P 80, Fig. 6.8-6.9)


INTRODUCTION

The vascular plants possess true conducting tissue consisting of xylem and phloem . They are said to possess true leaves, roots and stems. The also possess supporting tissue for more upright growth, stomata

(small pores) for the exchange of gases, and a protective layer of cutin which forms a cuticle. These characteristics allow vascular plants to get large in size. Some vascular plants also begin to remove themselves from moist environments because they need less or no water for reproduction. In ferns for example, a single spore can germinate in the soil to form a gametophyte. Sexual reproduction follows and soon the organism is established.

Station 25 – Division: Lycophyta (Club Mosses)

The first seedless vascular plant division recognized is the club mosses. Be able to recognize the example seen in the jar ( Lycopodium , p 87 – Fig. 6.41 – 6.46

).

1.

What vascular characteristics do the plants in this division demonstrate? (Leaves, Stems, or Roots)

2. Is the plant part of the gametophyte or sporophyte generation?

3.

What is the term used for small leaves with one vein?

What is the term used for specialized leaves that produce sporangia?

4.

Station 26 – Division: Pterophyta (Psilophyta -Whisk Ferns)

This is the second division of seedless vascular plants recognized. The most primitive of the pterophyte plants, the whisk ferns, resemble extinct fossil forms of the Paleozoic. Be able to recognize the example seen in the jar ( Psilotum, p 91 – Fig. 6.54 – 6.62

)

1.

What vascular characteristics do the plants in this division demonstrate? (Leaves, Stems, or Roots)



Station 27 – Division: Pterophyta (Sphenophyta - Horse Tails)

The second seedless vascular plant recognized as a pterophyte is the horsetails. Be able to recognize the example in the jar and the living example ( Equisetum , p 94 – Figs. 6.65-6.78

)

1. What vascular characteristics do the plants in this division demonstrate? (Leaves, Stems, or Roots)


3.

What is the term used for small leaves with one vein? Do they contain chlorophyll at maturity?

4.

What substance is found in the rough ribbed stem?

5.

What is the name of the small cones produced at the tips of specialized stems?

Station 28 – Divison: Pterophyta (Ferns)

The third seedless vascular plant pterophyte recognized is the ferns. Be able to recognize the examples in the jar and the living example ( Polypodium, Salvinia , p 97 – Figs. 6.79-6.99

)

1. What vascular characteristics do the plants in this division demonstrate? (Leaves, Stems, or Roots)

2.

Is the plant part of the gametophyte or sporophyte generation?

3.

What is the term used for larger leaves with more than one vein? What is the common name of a fern leaf?

4.

What is the name of the rolled up leaf? What is the name of the type of coiling?

5. What is the name of the specialized leaves that are used for reproduction?

Station 29 – Fern Frond

Examine the back of a fern frond under a dissecting scope. You should be able to detect clusters of sporangium called sori. The sori may be covered with a protective covering called an indusium . Be able to identify the following structures: frond, sori, sporangium, and indusium. (p 98 – fig. 6.85-6.92)


Station 30 – Fern Sporangium

Examine a prepared slide of a sporangium under the microscope. Be able to recognize the following structures : sporangium, annulus, lip cells, and spores.

( p 99, fig. 6.92c

)

1.

What is the name of the heavy walled brownish cells? What is their function?

2.

What is the name of the cells that are at the open ends of the annulus?

3.

Fern spores are all a single type but develop into a gametophyte with both sex organs (archegonium and antheridium). What is the term used for this condition?

4. Fern spores are wind disseminated and germinate after being transported to suitably moist habitats.

What do they give rise to?

Station 31 The Gametophyte Generation of a Fern

The gametophyte generation of a fern a heart-shaped prothallus. Under a dissecting scope, Locate the antheridia, which are usually interspersed among the rhizoids. Locate the archegonia, which are usually located by the apical notch. Be able to recognize the following structures: prothallus, apical notch, archegonia, antheridia, and rhizoids.

1.

What do the antheridia produce? What do the archegonia produce?

2.

What is the function of the rhizoids?

3.

What eventually grows out of the archegonia?

Station 32 – Prothallus with a growing Sporophyte

Under a dissecting scope, study a prepared slide of a prothallus with a growing sporophyte. Be able to recognize the following structures: prothallus, foot , root, and leaf. (P 100, Fig. 6.94 & 6.96)

1. What happens to the gametophyte prothallus after the sporophyte begins to grow?

Station 21 – Classification

Biology 2

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