23Mar 2014 by Vincent Summers 1 Comment

The One Cell Blob Amoeba

Biology
[caption id="attachment_19430" align="alignright" width="440"] Giant Amoeba - Chaos carolinense - Dr.Tsukii Yuuji. Image edited.[/caption] The amoeba is probably everybody’s concept of the simplest life form this earth has to offer. Consisting of one cell, with no particular shape, this nearly shapeless creature has featured in science fiction B-movies, portraying a monster that encompasses its victim from all sides, sucking it into oblivion, absorbing the poor captive into its protoplasm. Here is an image of the so-called brain-eating version (Naegleria fowleri). The CDC explores the topic of this one-celled species to a great extent, providing much information on it. [caption id="attachment_7879" align="alignright" width="300"] The brain-eating amoeba. Image CDC[/caption] Anatomy The amoeba possesses a cell wall, which encompasses its protoplasm. Its shape is completely mobile, and it can surround prey, re-forming its…
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23Mar 2014 by Vincent Summers No Comments

The Stentor Trumpet Animalcule

Biology
[caption id="attachment_16489" align="alignright" width="440"] Stentor roeseli[/caption] Resembling a trumpet or vase, varieties of stentor make up the largest known single-celled aquatic creature. Their name comes from the epic poem, “The Iliad,” in which Homer characterizes a herald, Stentor, as having a voice “as powerful as fifty voices of other men.” As with vorticella, the eating orifice of the trumpet animalcule is circled about with tiny hair like cilia. These hairs wave in sequence, sweeping food into its oral cavity. See the beautiful video (below), filmed by Dr. Ralf Wagner. It highlights the feeding process. In the vast majority of instances, organisms are made up of one or more cells, each with its own nucleus. The nucleus governs cell function and participates in cellular division or reproduction, providing a complete DNA…
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23Mar 2014 by Vincent Summers No Comments

The Cyclops Freshwater Copepod

Biology
[caption id="attachment_27434" align="alignright" width="480"] Cyclops bicuspidatus. - NOAA[/caption]In Greek mythology, Cyclops was a violent, one-eyed giant humanoid monster. The most famous of them is Polyphemus. He was the son of the Greek god Poseidon and the sea nymph¹ Thoösa. It is that one eye that defines the cyclops. And so a tiny fresh water copepod possessing one eye (sometimes red, sometimes black) is named cyclops as well. Thanks to its small size (0.5 to 2 millimeters) and its jerky movements, it (also the daphnia) has been nicknamed “water flea.” It is instructive to watch this brief video of a male. Description Cyclops feeds on plankton. It thrives in stagnant ponds. It does not require sexual fertilization to reproduce. But it does engage in sexual reproduction during periods of drought to…
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23Mar 2014 by Vincent Summers No Comments

Hydra: Octopus of the Microscopic World

Biology
[caption id="attachment_6105" align="alignright" width="440"] Hydra oligactis - CCA Share Alike 3.0 Unported by Lifetrance[/caption] Resembling a cross between an octopus and a sea anemone, tiny hydra lives in fresh water. It would make an excellent subject for a Japanese sci-fi movie. H. oligactis, seen at left, has a central stalk from which a number of tentacles radiate. The Real Deal Waving its tentacles in search of prey, the tiny creature thrives in among loose weeds. The creatures are carnivores. Scientists find them of special interest because of their great ability to regenerate. They are capable of living a long time. The base of the stalk secretes an adhesive that enables the miniature "octopus" to stick to surfaces. The tentacles contain nematocysts or stinging cells with neurotoxins that paralyze a victim.…
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23Mar 2014 by Vincent Summers 2 Comments

Daphnia Pulex: The Water Flea

Biology
[caption id="attachment_6098" align="alignright" width="440"] Daphnia - photo by Paul Hebert[/caption] Although there are other species, Daphnia pulex comes to mind when one thinks of the water flea. The tiny crustacean. D. pulex is cosmopolitan. That word means it is found throughout the cosmetic (surface) layer of the planet. The National Institutes of Health informs us that the water flea is “a versatile model system to investigate” biological systems. Also to investigate matters such as immunity, disease, and cellular function. Appearance Variability The image with this article, reveals the great beauty of this tiny creature. Enjoy this instructive one minute video. Another video, one-half minute in length, displays daphnia in an aquarium. The water flea's name comes from its appearance and jerky motions controlled by its antennae. These resemble arms with…
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23Mar 2014 by Vincent Summers No Comments

The Rotifer: Nature’s Vacuum Cleaner

Biology
[caption id="attachment_11522" align="alignright" width="440"] Mikrofoto.de-Raedertier_Ptygura_pilula_2.jpg[/caption] As a child, I was given a small microscope. It wasn’t very powerful, but some small life forms could be seen using it. I visited the fish pond in our back yard and scraped some mossy scum along its bottom. What I saw under the glass surprised me. It looked like an upright vacuum cleaner. It was a rotifer. Ever heard of a rotifer? Rotifers may be seen in this enchanting video... A Brief Description The rotifer has been described as "an animal like a large maggot which could contract itself into a spherical figure and then stretch itself out again; the end of its tail appeared with a forceps like that of an earwig".¹ This may best describe the bdellid rotifer. Its crown features…
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23Mar 2014 by Vincent Summers 1 Comment

The Eight Legged Tardigrade or Water Bear

Biology
[caption id="attachment_14073" align="alignright" width="440"] ESA Image by Dr. Ralph O. Schill[/caption] The eight-legged tardigrade or water bear may seem insignificantly small. In fact, it is microscopic. Yet it is capable of thriving at death’s door under near impossible conditions. It is the penultimate extremophile. Its official name, tardigrade, refers to the "bear’s" slow, lumbering movements. Its feeding habits earn it the nickname, moss piglet. In fact, water bears are harvested for research purposes from moss-covered tree stumps. Special Features of the Water Bear Water bears can survive temperatures near absolute zero.¹ Why doesn’t the water in its body form destructive ice crystals? It seems to be due to the presence of the disaccharide sugar trehalose. Trehalose is found in a number of lower life forms. It possesses unique properties. It…
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23Mar 2014 by Vincent Summers No Comments

The Quintessential Aromatic Hydrocarbon Benzene (Pt.3)

Chemistry
[caption id="attachment_18860" align="alignright" width="440"] Figure 1.[/caption] The aromatic hydrocarbon benzene, chemical formula C6H6, is the single most-often discussed of the aromatic hydrocarbons. It possesses the quintessential aromatic structure. How is that? It possesses the Hückel Rule correct number of 4n + 2 number π-electrons, for n = 1, and is flat. In addition, it meets all the other requirements for aromatic compounds. As an aromatic compound, its chemistry is considerably different than it would be if it existed as a mere cyclohexatriene isomer. We will discuss those differences in this, the third installment of our three-part article. Behavior of Hypothetical Cyclohexatriene Since cyclohexatriene would behave as if it were merely three conjugated1 double bonds, we would expect the compound to behave as any other alkene—rich in available electrons—only more so.…
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23Mar 2014 by Vincent Summers No Comments

The Quintessential Aromatic Hydrocarbon Benzene (Pt.2)

Chemistry
[caption id="attachment_6069" align="alignright" width="440"] Benzene De-localized Pi-system - CCA Share Alike 3.0 Unported by Vladsinger[/caption] In Part One of The Quintessential Aromatic Hydrocarbon Benzene, we saw that the so-called 1,3,5-cyclohexatriene was really not completely described by the structure that that name implies. It is equivalent to 2,4,6-cyclohexatriene (if you flip the 1,3,5- structure over, and you get the 2,4,6- structure), and includes a variety of other contributing factors. Although we did not list them, they may include ionic contributors.1 In general, these are discounted. Visualizing Benzene's Structure The conclusion is that the compound actually has six equivalent bonds between adjacent carbon atoms, forming six internal angles angle each equal to 60°. The bonds are each, then, “single-and-one-half” bonds between each carbon pair. The molecule is flat, even as a collection…
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23Mar 2014 by Vincent Summers No Comments

The Quintessential Aromatic Hydrocarbon Benzene (Pt.1)

Chemistry
[caption id="attachment_14959" align="alignright" width="440"] Cyclohexane - Chair Form[/caption] Benzene? What's that? Living creatures universally share an important characteristic: they all are constructed of carbon-containing compounds. For that reason, chemists call such compounds organic. Now the term organic has taken on additional meaning. Compounds that are similar, but not found in nature, are also called organic compounds. One group of organic compounds, whether found in nature or not, possess special properties—chemical and physical—that put them into a category apart. Once it was thought such compounds were distinguishable by smell or aroma. Each was labeled an aromatic, and—the property itself—aromaticity. Simple Hydrocarbons The simplest hydrocarbon1 is methane (CH4)—a gas. It possesses a tetrahedral structure, with a carbon atom at its center and four hydrogen atoms at the corners (See Figure 1). Since…
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