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Branches on the Tree of Life

The Branches on the Tree of Life: The Biology of ... series of core curriculum programs explores the "deep branches" on the tree of life to reveal a modern view of the classification and phylogeny of each group studied in the biology curricula. The narrated programs feature new techniques of microscopy, animation, and photography to reveal the structure, process, and behavior in living things.
  • Title ID 120-BBT
  • Science, Biology
  • 16 Programs
  • 28 Supplemental Files
  • 10th Grade through Post Secondary
  • Released in 2006 by BioMEDIA Associates
Included Programs
Supplemental Files

Included Programs

The Biology of PlantsRunning time is 14 minutes

Chapter List
Chapter 1: Photosynthesis.
Chloroplast structure: the process of photosynthesis. Includes light-trapping by chlorophyll, how energized electrons are transported through proteins embedded in the thylakoid membrane, and how their energy fuels reactions that produce ATP and NADPH. Charon dioxide feeds a cycle of reactions that form the simple sugar glucose, a basic cell fuel.
Chapter 2: Mosses and Liverworts: Non-vascular plants.
Mosses and Liverworts: non-vascular plants. Liverworts, with low growing flattened plant bodies, are almost always found in contact with water or wet soil. They produce male and female gametes. Mosses are an adaptable and diverse group, easily collected for study. Look for fruiting bodies and elaborate mechanisms for spore dispersal.
Chapter 3: Horsetails and Ferns: Primitive Vascular Plants.
Horsetails and Ferns: Primitive Vascular Plants. These plants boast a transport system for carrying water and materials around the plant body. With a vascular system, ferns, horsetails, and other grew tall, creating complex environments in which land animals could exist. Gametes are produced by small sexual plant (the prothallus) that grows from a spore. Fertilization occurs in a film of water.
Chapter 4: Angiosperms: The flowering plants.
Angiosperms: The flowering plants. These plants have developed the most elaborate sexual exchanges and need dispersal strategies-abilities that have produced an amazing diversity of plants, ranging from the arctic to the equator.
Chapter 5: Summary
Observation Section: Non-narrated video of living plant structures.

The Biology of VirusesRunning time is 18 minutes

Chapter List
Chapter 1: Discovery and Laboratory Study of Viruses
Discovery and Laboratory Study of Viruses: In the 1940s the newly invented electron microscope produced the first images of viruses, Virologists have learned to grow viruses in cultures of living cells.
Chapter 2: Virus Replication
Virus Replication: The T4 bacteriophage virus demonstrates a direct form of virus reproduction.
Chapter 3: Retroviruses (HIV)
Retroviruses (HIV): RNA viruses use reverse transcriptase to produce viral DNA, causing an infective cycle that compromises the host's immune system.

The Biology of FungiRunning time is 22 minutes

Chapter List
Chapter 1: What and Where are Fungi
Fungi are unicellular or tubular multicellular forms with cell walls containing chitin. These eukaryotes feed by absorbing food molecules obtained through external digestion. Fungi are all around us - their hyphae penetrate soils, decaying material, and even living tissues (in mycorrhizal associations and as parasites).
Chapter 2: Chytrids
Probably the oldest group of living fungi, the Chytrids consists of aquatic decomposers and parasites with flagellated spores and gametes.
Chapter 3: Zygomycetes
Zygomycetes include many molds that aid in the decay of dead plants and other organic material such as feces. A rotting pumpkin illustrates a typical Zygomycete life-style. Bread mold and Pilobolus, the tiny 'canon fungus', provide a fascinating look at adaptations for spore dispersal in this group.
Chapter 4: Ascomycetes and Basidiomycetes
The phylum Ascomycota, the true yeasts, many important molds, morels, cup fungi, and the fungal partner of most lichens.Yeasts used in fermentation and Penicillin used in antibiotics production are among the important economic fungi. Sexual reproduction in multicellular ascomycetes is through scospores formed inside the dikaryote. In lichens, the ascomycete associates with either a green alga, or a cynanbacterium. Lichens are important pioneer species in many ecosystems and those associated with
Chapter 5: The Lichens
In lichens, the ascomycete associates with either a green alga, or a cyanobacterium. Lichens are an important pioneer species in many ecosystems and those associated with nitrogen-fixing cyanobacteria play a crucial role by adding nitrogen to forests.
Chapter 6: Phylum Basidiomycota
The phylum Ascomycota includes the true yeasts, many important molds, morels, cup fungi, and the fungal partner of most lichens. Yeasts used in fermentation and Penicillin used in antibiotics production are among the important economic fungi. Sexual reproduction in multicellular ascomycetes is through scospores formed inside the dikaryote. In lichens, the ascomycete associates with either a green alga, or a cynanbacterium. Lichens are important pioneer species in my ecosystems and those asso
Chapter 7: Symmary
This group includes a variety of parasitic rusts and smuts, some with complex life cycles involving two hosts., But most of the basidiomycetes are the familiar mushroom-producing fungi. The bulk of the fungus is the mycelium, hidden in the ground or decaying log. Mycorrhizal associations (fungal hyphae associating with plant roots) enable many plants to grow faster, while providing energy to the symbiotic fungus.

The Biology of AlgaeRunning time is 19 minutes

Chapter List
Chapter 1: Algae, What is It?
Algae, What is IT? The organisms we call algae come from divergent evolutionary lines: red algae, brown Algae, green algae, dinoflagellates and euglenids. All are eukaryotic cells including many single cell species, colonial forms, and multicellular kelps and seaweeds.
Chapter 2: Chromista
Chromista - Chromista is an evolutionary line of algae containing chlorophyll A and chlorophyll C. It includes the brown seaweeds, the golden brown micro-algae known as chrysophytes, diatoms, and a number of non-photosynthetic organisms.
Chapter 3: Dinoflagellates
Dinoflagellates - Concentrations of dinoflagellates (red tides) are responsible for fish kills and paralytic shellfish poisoning in humans. Genetic comparisons show that the dinoflagellates are more closely related to ciliated protests than to other lines of algae. This segment shows structure and behavior of Gymnodinium and Ceratium, two of the most genera found in freshwater habitats.
Chapter 4: Euglenids
Euglenids - Euglena is a famous single celled protist often seen in biology classes. Euglena's structure and behavior are shown along with a diversity of green and non-green euglenid species.
Chapter 5: The Green Line of Evolution
The Green Line of Evolution - This highly branched evolutionary line is characterized by having chlorophylls A and B and includes the green algae and plants. Observations introduce some common green algae genera: Closterium, Micrastarias, Nitella, and Spirogyra. The Spirogyra life-cycle demonstrates a survival strategy found in many fresh water algas - a sexual process (conjugation) that leads to the production of drought-resistant zygotes. Colonial algae show how a transition from single cell

The Biology of CnidariansRunning time is 12 minutes

Chapter List
Chapter 1: Cnidarians
Cnidarians (formerly Coelenterates) make up three class of simple animals on the Tree of Life: Hydrozoa, Scyphozoa and Anthozoa. As a group, cnidarians share a short life of common features: two cell layers, tentacles armed with stinging cells, a single ended digestive cavity, and a nerve net that allows some general responses to environmental stimuli. In 1997, scientists succeeded in cloning a mammal, but cnidarians have been in the cloning business for nearly 600 million years. One of the b
Chapter 2: Class Hydrozoa
Class Hydrozoa: Feeding behavior in Hydra; Stinging cells; Budding; Hydra sex; Clorohydra (green algae symbionts); Obelia life cycle; Portuguese Man-O-War, a hydrozoan colony
Chapter 3: Class Scyphozoa
Class Scyphozoa: The Jellyfishes showing form, functions and reproduction.
Chapter 4: Class Anthozoa
Class Anthozoa: Sea Anemone reproduction and behavior with Corals.

The Biology of Rotifers and NematodesRunning time is 15 minutes

Chapter List
Chapter 1: Rotifers
Rotifers: These tiny multicellular animals are often smaller than their unicellular neighbors. Many have "wheel organs" that pride locomotion and feeding currents, a well-developed food grinder (the masta), and bundles of flame cells called "flame bulbs" that move water and waste products to the bladder for elimination. In some species males are rate or unknown.
Chapter 2: Nematodes
Nematodes: Roundworms are seldom seen but easily found. Tree moss, leaf litter and compost piles swarm with nematodes. Examine these materials using a stereo microscope or hand-magnifier to discover and study free-living nematodes. Human infesting nematodes such a pinworms, hookworms, and trichinid worms are familiar temperate zone parasites. Many more types are found in tropics. The screen captures from the internet show a condition known as elephantiasis of the scrotum, caused by worms cloggin

The Biology of FlatwormsRunning time is 15 minutes

Chapter List
Chapter 1: Free-living Flatworms (Class Turbellaria)
Class Turbellaria - the free-living flatworms Examples show how primitive, almost microscopic species gulp in protozoans. Larger flatworms use slime to trap their prey which is then partially digested before being sucked into the worm's stomach.
Chapter 2: Monogenetic Flatworms (Class Monogenea)
Class Monogenea - Although they resemble flukes (class Trematoda), these are ectoparasites of fish and amphibians with highly efficient sets of hooks for hanging on.
Chapter 3: Flukes (Class Trematoda)
Class Trematoda - the flukes Every vertebrate animal plays host to parasitic flukes. The adults live in their host's organs, particularly the intestine, bladder, blood vessels, liver and lungs, depending on the fluke species. A general life-cycle for trematodes is illustrated.
Chapter 4: Tapeworms (Class Cestoda)
Class Cestoda - the tapeworms; as adults they are intestinal parasites, absorbing their host's food in predigested form. A tapeworm is basically a string of maturing reproductive segments (proglottids) held in the intestine by a specialized segment, the scolex. The cestode life-cycle pattern is illustrated.

The Biology of EchinodermsRunning time is 14 minutes

Chapter List
Chapter 1: Phylum Echinodermata
The 'spiny-skinned' animals, Phylum Echinodermata, are an entirely marine group of animals characterized by radial symmetry as adults, a calcereous endoskeleton, and a water vascular system.
Chapter 2: Sea Stars (Asteroidea)
Chapter 3: Brittle Stars and Basket Stars (Ophiuroidea)
With over 2000 species, this is the largest class of echinoderms. Basket stars are sedentary suspension feeders, but brittle stars move actively using a paddle-like motion of the arms.
Chapter 4: Sea Urchins and Sand Dollars (Echinoidea)
These organisms exhibit a range of defense adaptations involving spines and pedicellaria. A detailed look at development reveals larval stages and metamorphosis to the adult radial form.
Chapter 5: Sea Cucumbers (Holothuroidea)
Sea cucumbers are suspension or detritus feeders with a partial bilateral symmetry as adults.
Chapter 6: Feather Stars (Crinoidea)
A diverse group of suspension-feeding animals, feather stars are most abundant in tropical waters.
Chapter 7: Summary
Echinoderms are one branch of the deuterostome line of animal evolution, the branch to which Chordates also belong. Narrated modules cover phylum characteristics and key biological details for five classes: sea stars, brittle stars and basket stars, sea urchins and sand dollars (including developmental stages), sea cucumbers, and crinoids (feather stars).

The Biology of MolluscsRunning time is 15 minutes

Chapter List
Chapter 1: Phylum Origins and Characteristics
Phylum: Explore the origins and characteristics.
Chapter 2: Class Polyplacophors
One of the four main classes of Molluscs: Class Polyplacophora - chiton characteristics, feeding and diversity.
Chapter 3: Class Gastropods
One of the four main classes of Molluscs: Class Gastropoda; Seecharacteristics, morphology, movement, feeding with radula, nudibranchs and their defenses, hermaphroditic mating, gastropod life history and larvae pulmonate diversity and behavior.
Chapter 4: Class Pelecypoda
One of the four main classes of Molluscs: Class Pelecypoda - clams and mussels, byssus formation, scallop escape behavior, ciliary-mucous feeding, freshwater clams and glochidia larvae.
Chapter 5: Class Cephalopda
One of the four main classes of Molluscs: Class Cephalopda - behavior, fossil types, Nautilus, Sepia, octopus behavior and life cycles.
Chapter 6: Summary
Mollusc Evolution and Diversity - The radiation of mollusks into different habitats. Mollusc development indicates evolutionary relationships.

The Biology of AnnelidsRunning time is 18 minutes

Chapter List
Chapter 1: Introduction
This is an introduction to Annelids which are abundant in marine and freshwater ecocystems and in moist terrestrial habitats.
Chapter 2: Polychaetes, Class Polychaeta
Segmentation and parapodia. Avoiding predators adaptations for living in low oxygen environments. The burrowing lifestyle. Feeding strategies. Reproduction and life history.
Chapter 3: Oligochaetes, Class Oligochaeta
Common freshwater oligochaetes. Feeding method. Circulatory systems. Earthworm anatomy and reproduction.
Chapter 4: Leeches and Crayfish Worms, Class Hirundea
Closely allied to the oligochaetes, this class, includes parasitic, predatory and scavenger leeches and the commensal worms often found on crayfish.
Chapter 5: Summary and Annelid Evolution
Larval biology and molecular genetics confirms Annelids as relatives of the Molluscs.

The Biology of ArthropodsRunning time is 25 minutes

Chapter List
Chapter 1: Introduction
This is an introduction to Arthopods. Arthropods are organisms with hard exoskeletons and jointed appendages Phylum Arthropod has by far the greatest diversity and greatest biomass of all animal phyla.
Chapter 2: Crustaceans
Topics include Copepods, Ostracods, Cladocerans (Daphnia and others), Eubranchiopods, Amphipods and Isopods, Decapods, Barnacles.
Chapter 3: Chelicerates
Topics include Scorpions, Pseudoscorpions, Whip Scorpions, Spiders, Ticks and mites.
Chapter 4: Uniramians
Topics include Millipedes, Centipedes, Insects.

The Biology of ChordatesRunning time is 18 minutes

Chapter List
Chapter 1: Introduction to Phylum Chordata
Unifying characteristics of the Phylum Chordata.
Chapter 2: Urochordates
Urochordata (sea quirts), including details of structure, feeding and reproduction.
Chapter 3: Cephalochordates
Cephalochordata (lancelets), including Pikaia, a fossil cephalochordate, and Branchiostoma (Amphioxis), a modern cephalochordate.
Chapter 4: Vertebrates
Hagfish (slim eels) and lampreys are remarkable fish-like vertebrates with ancestral characteristics. Major steps in fish evolution leading to the cartilaginous and bony fishes. Evolution of fish fin structures, walking appendages and movement onto land as modeled by a walking fish, the mudskipper.
Chapter 5: Amphibians and Reptiles
Chordates become semi-aquatic - the amphibians. The amniotic egg evolves leading to the diversification of land vertebrates.
Chapter 6: Aves
Early egg-laying vertebrates gave rise to modern reptiles and mammals and numerous extinct groups including the dinosaurs. Modern birds are living descendants of one dinosaur group.
Chapter 7: Mammals
A branch of the mammal line, the monotremes, shows the ancestral condition of amniotic egg production. Later branches show marsupial and placement development.

The Biology of ProtistsRunning time is 20 minutes

Chapter List
Chapter 1: What is a Protist?
What is a Protist? The modern tendency is to call all single celled eukaryotic organisms Protists. This, however, is not a tidy group occupying a single clearly defined branch on the tree of life. Today's single celled eukaryotes come from diverse branches of life, some lines splitting from others at the dawn of eukaryote evolution.
Chapter 2: The Euglenids
The Euglenids: Euglenids are so diverse and so different from other lines of life some biologists would like to see them placed in a kingdom of their own.
Chapter 3: Diatoms and Their Unlikely Relatives
Diatoms and Their Unlikely Relatives: This module shows that structure along is not a sufficient guide to relationships.
Chapter 4: Amoebas and Heliozoans
Amoebas and Heliozoans: These fascinating protists are adept at engulfing other organisms.
Chapter 5: Green Protists
Green Protists: This module shows the considerable diversity of the green line of evolution.
Chapter 6: Colonial Protists
Colonial Protists: Colonial protists created an evolutionary bridge between single cells and simple multicellular organisms.
Chapter 7: Insiders
Insiders: Every animal species has one or more protist symbionts. Some are parasites, other harmless commensals, and some actually help out.
Chapter 8: Ciliated Protists
Ciliated Protists: Here are some of the classical protozoans so often seen in pond water samples-the dinosaurs of micro-space.
Chapter 9: Paramecium
Paramecium: A biology lab standby, Paramecium demonstrates how life processes are carried out by independently living cells.

The Biology of SpongesRunning time is 15 minutes

Chapter List
Chapter 1: Cell Types and Feeding
Introduction: Phylum Porifera, the sponges, includes several thousand aquatic species with four main features: filter feeding through pores; unique cells call choanocyes, simple tissues with no internal organs, and an internal Skelton of fibers or spicules.
Chapter 2: The Sponge Skelton
Spicules are elaborate crystals that form a supporting scaffold.
Chapter 3: Three Classes of Sponges
The three classes of sponges: Class Calceria, Spicules in this group break down in acid: Class Hexactinellida: Some hexactinelid sponges create deep water reefs; Class Demospongia: The most diverse group of ponges includes species with a firous skeleton and species with spicules made from silicon dioxide.
Chapter 4: Sponge Ecology
Spicules in this group break down in acid.
Chapter 5: Reproduction and Evolution
Some Hexactinellida sponges create deep water reefs.
Chapter 6: Summary
The most diverse group of sponges includes species with a fibrous Skelton and species with spicules made from silicon dioxide.

The Light Microscope: Window on the MicrocosmRunning time is 17 minutes

Chapter List
Chapter 1: Leeuwenhoek and the Discovery Scope
The inventor of microscope and how you can make a simple microscope.
Chapter 2: The Compound Microscope
Simple Microscopes: A microscope with a single lens. Even a simple hand lens will reveal protozoans and other small organisms, when brightly lit against a dark background.
Chapter 3: The Optical Property of Resolution
Compound Microscopes: Much emphasis is placed on magnification, but "magnification" simply refers to the degree of enlargement of the subject. Enlargement does not necessarily reveal more detail in the subject. Resolution of the detail is determined by the interplay of three systems: the objective lens, the condenser lens, and the iris.
Chapter 4: Increasing Color and Contrast in Living Subjects
The Limits of Light: White light has an average wave length of around .6 micrometers. The wave length limit explains why no further benefit can be gained by increasing the magnification of the microscope lens systems.
Chapter 5: Microscopic Observations
Functions and Techniques: The function of the condenser and iris diaphragm, bright field and dark field and dark field imaging, oil immersion technique, and viewing with polarized light.

The Biology of BacteriaRunning time is 17 minutes

Chapter List
Chapter 1: Bacteria and Atmospheric CO2
Bacteria & Atmospheric CO2: Bacterial decomposition produces a significant seasonal spike in atmospheric CO2.
Chapter 2: Decomposition-based Food Chains
Decomposition-based Food Chains: Materials are recycled in ecological systems through the action of bacteria.
Chapter 3: Reproduction and Behavior
Reproduction & Behavior: With a doubling time of around 30 minutes, bacteria populations can explode under certain conditions. Bacteria have behavior that enables them to locate and remain near nutrients.
Chapter 4: Bacteria Shapes and Structures
Bacteria Shapes and Structures: Spheres, rods of many shapes, spirals, spirochaetes, and gliding filaments.
Chapter 5: Bacteria are Prokaryotic Cells
Bacteria are Prokaryotic Cells: Contrasts bacteria structures with eukaryotic cells.
Chapter 6: Nitrogen Fixation
Nitrogen Fixation: Most nitrogen compounds incorporated into proteins originate with bacteria.
Chapter 7: Cyanobacteria
Cyanobacteria: They developed water-splitting photosynthesis and produced our oxygen-rich atmosphere.
Chapter 8: Bacteria as Symbionts
Bacteria as Symbionts: While some bacteria cause disease, may are beneficial to their hosts.
Chapter 9: Summary
Additional Observations: A 12-minute observation of living bacteria from nature.

Supplemental Files

MARC Records for BBT
MARC records for the series Branches on the Tree of Life
Biology of Plants Study Guide
Biology of Viruses and Bacteria Study Guide
Biology of Algae Study Guide
Biology of Fungi Study Guide
Biology of Fungi Answer to Review Questions
Biology of Fungi Image Bank Guide
Biology of Cnidarians Study Guide
Biology of Rotifers and Nematodes Study Guide
Biology of Flatworms Study Guide
Biology of Echinoderms Study Guide
Biology of Echinoderms Answers to Review Questions
Biology of Echinoderms Image Bank Guide
Biology of Molluscs Study Guide
Biology of Molluscs Image Bank Guide
Biology of Annelids Study Guide
Biology of Annelids Image Bank Guide
Biology of Arthropods Educators Guide
Biology of Arthropods Image Bank Guide
Biology of Chordates Educators Guide
Biology of Chordates Q and A
Biology of Chordates Questions for Discussion
Biology of Chordates Image Bank Guide
Biology of Protists Educators Guide
Biology of Sponges Study Guide
Biology of Sponges Answers to Review Questions
Biology of Sponges Image Bank Guide
Biology of Microlife The Light Microscope Study Guide