Download PM Guides doc - Distribution Access

A BioMEDIA ASSOCIATES Video Program Guide
The ‘Biology Of’ Video Series
The Biology of Algae
The term “algae” is a catch-all for several evolutionary lines of photosynthetic
organisms: Red Algae (plastids with chlorophyll A), Brown Algae (with chlorophyll A and C), and Green Algae(Chlorophyll A and B). These photosynthetic
organisms play vital roles in aquatic and marine ecosystems, providing oxygen,
food and shelter for vast communities of living things.
LOOKING AT SOME COMMON MICRO-ALGAE
Diatoms are an abundant group of brown algae characterized by the ornate
glass houses they produce. In diatoms food made by photosynthesis is stored in
the form of oil droplets. Planktonic species regulate their oil content as a means
of achieving buoyancy. In many planktonic species elongated spines act as
stabilizers preventing sinking.
Volvox , the large colonial alga of lakes and ponds, can swim, allowing it to
remain in a light zone favorable for photosynthesis.
The large algae cells sampled from the pond bottom belong to the genus
Netrium.
Algae in the food chain is converted at a ten to one ration, so imagine how many
pounds of micro algae are represented by a one pound fish that feeds on aquatic insects that in turn feed on
micro algae.
LARGE ALGAE ADAPTATIONS: Related to the unicell brown algae, are large marine organisms known as kelp.
Bull kelp can reach from the sea floor. A gas filled float bulb keeps them suspended in the sunlit waters. The
sea palm, (and other brown algae that live on wave exposed rocks) produce finger-like hold fasts that grip the
rocks.
SYMBIOTIC ALGAE
Many kinds of algae live upon aquatic or marine animals (horse shoe crab example). Certain micro algae live
inside of protists and within some kinds of invertebrate animal.
CYANOBACTERIA
Although they have been known as blue-green algae for many years, we now know that these organisms are
actually bacteria. There are descendants of the first cells to evolve water splitting photosynthesis. Early
cyanobacteria pumped the first oxygen into earth’s atmosphere, and changed the course of life. The examples
shown are Oscillatoria.
MULTICELLULAR ORGANISMS FROM SINGLE CELLED ANCESTORS
Colonial algae show us how this may have happened by way of colonial stepping stones.
VOLVOX
Asexual reproduction through daughter colonies. Sex through gametes produces resistant zygotes.
Review all BioMEDIA ASSOCIATES products at
www.eBioMEDIA.com
Orders: P.O. Box 1234 Beaufort, SC 29901-1234
877. 661.5355 toll free . 843.470.0237 fax
A BioMEDIA ASSOCIATES Video Program Guide
The ‘Biology Of’ Video Series
The Biology of Plants
For over three billion years photosynthesis has tapped into the constantly
available energy of light, converting this energy into the chemical bond energy
that holds together the molecules of life. The animated sequences are taken
from the BioMEDIA videodisc—Visualizing Cell Processes. They show: The
structure of chloroplasts, light trapping by chlorophyll, how energized electrons
are transported through proteins embedded in the thylakoid membrane and
how their energy is used to pump hydrogen ions (protons) into the thylakoid
space. The source of hydrogen is water, split through reactions occurring on the
thylakoid discs. The exit flow of protons from the thylakoid space is through
ATP synthase, an enzyme that couples a phosphate group to an ADP to make
ATP, life’s universal energy carrier. With input of electron energy from another
cluster of chlorophylls, another energy carrier, NADPH is generated. The
reactions producing ATP and NADPH are refereed to as the light dependent
reactions.
In the stroma (the space surrounding the thylakoid discs) carbon from carbon
dioxide feeds a cycle of reactions driven by ATP and NADPH. The three carbon
compound Phosphogyceraldehyde (pGAL) is one of the products. pGAL molecules can be combined to form the simple sugar glucose, a basic cell fuel.
These reactions occur day or night and so are called the light independent
reactions of photosynthesis. Other important building blocks are also synthesized in the chloroplast such as
amino acids, nucleic acids, fatty acids, all vital to life.
Water splitting photosynthesis evolved around two billion years ago in organisms resembling today’s
cyanobacteria. By one million years back, cells with nuclei had developed symbiotic relationships with
cyanobacteria symbionts. The photosynthetic symbionts eventually evolved into chloroplasts and the waters of
planet Earth became populate with nucleated cells that carried out photosynthesis. Colonies of green protists
provided the evolutionary stepping stones to the first simple plants around half a billion years back.
Liverworts, with low growing flattened plant bodies, are almost always found in contact with water or wet soil.
Liverworts produce male and female gametes to generate offspring that carry a combination of their parent’s
genetic variations. Mosses are an adaptable and diverse group, easily collected for study. Look for fruiting
bodies with elaborate devices for spore dispersal. Sexual exchange of gametes occurs in water provided by rain
drops.
Gymnosperms produce “naked seeds” (as compared to flowering plants, where the seed develops within an
ovary). Also, in this group, sperm travels to egg through air-born pollen. One group, the conifers, are dominant
plants today, producing forest that spread through the temperate and subarctic regions of the world.
Angiosperms, the flowering plants, have developed the most elaborate sexual exchanges and seed dispersal
strategies; abilities that have produced an amazing diversity of plants, ranging from the Arctic to the equator.
Silent Observations Sections
Onion membrane . cyctoplasmic streaming . osmosis . moss leaves . vascular systems. onion root.
Review all BioMEDIA ASSOCIATES products at
www.eBioMEDIA.com
Orders: P.O. Box 1234 Beaufort, SC 29901-1234
877. 661.5355 toll free . 843.470.0237 fax
A BioMEDIA ASSOCIATES Video Program Guide
The ‘Biology Of’ Video Series
The Biology of Fungi
Fungi join with bacteria in breaking down dead organic material. In this program, the various types of fungi are recognized by their structures and life cycle
stages. Certain fungi (mycorrhizae) form symbiotic relationships with plants.
Their help in absorbing nutrients and water probably aided vascular plants in
colonizing the land.
Free living fungi obtain their nutrients much in the same way as bacteria, by
secreting digestive enzymes into their environment (typically dead animal or
plant material, or animal fecal wastes) and absorbing the digested products.
Over 100,000 kinds of fungi have been discovered so far, and this is probably a
very small percentage of fungi diversity.
FUNGI —A VERY OLD KINGDOM OF LIFE
Modern genetic comparison shows that fungi are more closely related to
animals than to plants, where they were classified for many years. They are
often treated as one of the five kingdoms of life. Due to their soft bodies there is
very little fossil record of early fungi. However, other lines of evidence suggest
that they split from other multicellular organisms very early—perhaps 700
million years ago. 150 million years later animals began their explosive diversification, plants, somewhat later.
HYPHAE AND SPORES
Hyphae are fungal tubes that grow through organic material. When sufficient nutrients have been absorbed
and conditions are right, the hyphal mass will produce a fruiting body. In one group of fungi (molds) this is a
spherical spore factory called a sporangium. The spores can be dispersed by air or with the help of insects.
WATER MOLDS
Some of the simplest fungal-like organisms live in water. They colonize and decompose drowned insects and
dead plants. However, the water molds may not be as closely related to fungi as they appear. Some biologist
believe that water molds developed their fungal-like characteristics independently—not from a fungal ancestor.
However, water molds are easily cultures and make good subjects for studying hyphae, spore production and
sexual processes.
CHEMICAL WARFARE
Decomposers vie for nutrients and this has led to fungi evolving chemical defenses that can cut out the competition—particularly competition from bacteria. A famous example is the antibiotic produced by the mold Penicillium.
KINDS OF FUNGI — THE CLASSICAL TAXONOMY
Phycomycetes — that branch of fungi that produces spores in a sporangium
Basidiomycetes — mushrooms, puff balls, rusts and smuts, bracket fungi, coral fungi , birds nest fungi—
organisms that produce spores on a basidium. Mushrooms, the most familiar group, live most of their lives as a
tangled mass of hyphae known as a mycelium. The mushroom is the short-lived fruiting body the produces the
spores.
Ascomycetes— produce spores in an ascus Certain Ascomycetes live in the fecal piles of herbivores. These
species have developed amazing spore dispersal mechanisms assuring that their spores are eaten by a grazing
animal.
Review all BioMEDIA ASSOCIATES products at
www.eBioMEDIA.com
Orders: P.O. Box 1234 Beaufort, SC 29901-1234
877. 661.5355 toll free . 843.470.0237 fax