Phylum hemichordata

Phylum hemichordata :

Once grouped as chordates, the Hemichordate are now a distinct phylum.

    They are group of worm like marine animals with apparent and intriguing relationship with the echinoderms and the chordates.

     The acorn worms (hemichordates) are believed to be a link between the vertebrate and invertebrates.

    The hemichordata lacks the notochord which excludes them from the chordates,however,they exhibit the presence  of the pharyngeal gill slits and in some species,a dorsal hollow nerve cord.

Classification  of the phylum hemichordata

The phylum comprises of two classes :

*class enteropneusta

*class pterobranchia

Class enteropneusta : This is a cylindrical, soft bodied and worm like animal with ciliated body surfaces. They are acorn worms.  They are common inhabitants of shallow water, with most species forming mucus lined burrows in Sandy or muddy sediments. The body is long and narrow and is divided into three distinct regions.

 The anterior called the proboscis is followed by a narrow collar regions and then the bulk of the body called the trurik.

The three body regions correspond with typical deuterostome body division:protosome,mesosome and metasome e. g. Balanoglossus, Ptychodera.

Acorn worm(saccoglossu)

Class pterobranchia : They exhibit a dorsal extension of the pharynx,forming an anterior stimichord just like the enteropneusta, which serves to support the surrounding tissues. However, they differ from the enteropneusts by possessing ciliated, anterior tentacles and a U shaped gut. Although, most members of this group have rigid tubes that they secretes e. g. Cephalodiscus.

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Phylum echinodermata

Phylum echinodermata:

The echinoderms are mostly marine animals. They include the sea stars, sea lilies, feather stars, star fishes, sea cucumber, sea urchin .some live in oceans and at great depth.

      Echinoderms are the most abundant group of animals that are available on the deep sea floor. Most of  them are slow moving animals and most use the tube feet(podia) for attachment in the bottom of the  sea.

      Although their free living larval stages are bilaterally symmetrical, most adult echinoderms show a basic five -point (pentamerous) radial symmetry. As radially symmetrical animals ,they lack cephalization. Thus adult echinoderms generally do not have anterior and posterior ends. Instead, the body surfaces are designated as being with either oral or aboral.

They have an internal skeleton compose largely of calcium carbonate. Typically, this skeleton bears projecting spines which give the body surfaces a spiny appearance.

       Their most distinctive feature is the WATER VASCULAR SYSTEM which consists of a series of fluid -filled canals. During  locomotion, the water vascular Canal operates like a hydraulic system. Echinoderms lack definite excretory system.

Characteristics of the   echinodermata

* Most echinoderms are typically pentamerous, that is the body is usually with five -radiating areas.

* They have skeleton  made of calcareous materials. The exoskeleton carries spines on them.

* The digestive tract is complete.

*Most echinoderms are dioecious (sex are separate) and fertilization is commonly external.

Classification of the phylum echinodermata

There are quite  a huge number of classes but five (5) classes of existing echinoderms are usually recognized

* Class of Asteroidea

* Class of Ophiuroidea

* Class of Echinoidea

* Class of Holothuroidea

* Class of Crinoidea

Class of asteroidea: They are the star fishes. They possess arms and a basically star-shaped body.

Class of Ophiuroidea :They are the brittle stars and the basket stars. They lack the anus and the tube feet lack suckers.

Class Holothuroidea :They are the sea cucumber. They are soft bodied animals. They have slender bodies which are elongated at both ends.

Class of Crinoidea : The Crinoids are the most primitive. They include the sea lilies  and the feather stars.

Class of Echinoidea :These are the sea urchins and the sand dollar. They are heart-like in shape  and the tube feet end with suckers.

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Preservation of animal species

Preservation of animal species 

Preservation  can be defined  as the use of chemical, physical or other            Processes to prevent  microbial
and physical damages to biological specimens with a view of retaining their  original  form and prolonging their  storage life.

    The procedure  for preservation of animal  specimens varies greatly from  one animal group  to another.
      In most cases, the animal must first be killed or narcotised in a suitable  way so as to leave the tissues  in a state ,which is proper for display.
     The specimen is then fixed in this  condition and finally preserved. This final preservation is normally made either in a solution of ethanol or methanal (formalin).

Techniques  in fixing and preserving animal materials
     Fixation is a chemical process, which stops autolysis  and stabilizes protein components of tissues so that in
subsequent processing the tissue retains as fully possible the form they had in life.
     Preservation allows materials to be stored indefinitely by destroying any microbial action, which could degrade the specimen.
    The choice of fixation will depend upon the animal material to be fixed and the purpose for which it is being fixed.
Narcotisation :This is also known as relaxation and is an interim technique for animals since many are highly contractile and assume  grossly distorted  postures if placed straight into fixative.

The main factors to be considered in 

Speed of penetration : This determines the size of specimen that can be fixed.
Hardening: Some chemical like ethanol  is particularly liable to cause tissues to harden on prolonged exposure to high concentration.
Shrinkage :Certain fixatives such as ethanol and mercuric chloride  cause  tissues to shrink thus distorting the specimen  significantly.

Preservation techniques

Wet preservation : Fhis is used mainly for animals and is usually preceded by narcotisation. The process of fixation is then comparatively straight forward. Most times, it is necessary to arrange the body and appendages of the animals using tape.

* A 5-10%v/v aqueous solution of formalin(=40% v tv aqueous  formaldehyde neutralized with calcium carbonate to prevent any acidity in the solution resulting in the slow dissolution of calcareous  structures.)
*50-70% ethanol : Ethanol is inflammable, highly volatile and tends to cause shrinkage and decolorization in soft bodied animals. Pass  them slowly through a graded series of concentrations to minimize this problem.

Dry preservation
This form of preservation is used mainly for vertebrate taxidermy and for arthropods  and other invertebrate species. The hard exoskeleton of arthropods are easily preserved in dry state since the skeleton  prevents collapse and loss of form upon drying.

Taxidermy : it is a type of dry mounting where the vertebrate is carefully skinned to remove the body and then replace with false body made of polystyrene, foam or cork etc.

Storage : Careful maintenance of specimen after fixation /preservation process is very important. The storage conditions for materials preserved either in wet or dry state.

Labelling : labelling must be comprehensive and contain information on the fixative and preservation processes  as well as ecologically and taxonomic details.

Reasons for animal preservation

* it prolongs the storage life of the  specimens.
*it prevents  the attack of micro–organisms like bacteria  and fungi that causes  spoilage.
* it helps in the preservation of large quantities of specimen needed for laboratory studies.
*extinct animals specimens can be preserved  for future study.

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fractional distillation of crude oil

fractional distillation of crude oil 

In the fractional  distillation of crude oil,the crude oil is heated above 400c and pumped

into the fractionating column where the components condense at their respective boiling  points.

         Conversion process

Conversion processes are the technique that are used to  improve  the quality of petrol product  after  initial distillation.

The techniques  used are:

* Hydro treating

* Catalytic  reforming

* Catalytic cracking

   Hydro treating: It is a refining process for removing sulphur  and other undesirable  elements from  petroleum  products.

       Catalytic reforming : catalytic reforming is a chemical process used to  covert linear hydrocarbons to high brand hydrocarbon.

Catalytic cracking :This is the  breakdown of higher molecular weight petroleum fraction into lighter ones with the use of catalyst.

It can yield  petroleum of higher octane number. Example of octane

number is 2,2,4 trimethylpentane

                                                             

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Reaction of ethanoic acid

Reaction of ethanoic acid 

MATERIALS

* ethanoic acid

*sodium ethanoate

*potassium permanganate

*mercury (ii) chloride

*ammoniacid  silver oxide

*concentrated  tetraoxosulphate (vi) acid

*iron(iii) chloride

APPARATUS

*test tubes

*bunsen burner

*measuring cylinder

*test tube pack

PROCEDURE : mix five drops each of ethanoic acid and ethanol

In a test tube, followed by the addition  of three drop of concentrated

Tetraoxosulphate (vi) acid. Warm the mixture  gently  and pour it into a boiling  tube about

half full of water.

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idioms

Idiomatic expression 

What is an idiom:An idiom is an expression  whose meaning  cannot  be arrived as by giving

a definition  to the individual works that makes up the expression.  In other words an idiom is a fixed expression.

Examples of idioms and their meanings 

* A black leg (one who betrays people)

*To smell a rat (to be  suspicious)

*To have a headache like a  sieve (to be  forgetful)

*To bury the hatchet  (to settle a quarrel)

*A green horn (an inexperienced  person)

*To keep at arm's length (to avoid a person)

*To dig someone in the ribs (to make unkind remarks about a person)

*To be at sixes and seven ( to be  confused)

*To kiss to the dust (to die)

*To hit the nail at the head( to go straight to the point)

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figures of speech

                FIGURES OF SPEECH

This  is a figurative part of speech.

 It is a figurative  in the sense that the words or sentence  used by the writer helps to create an image in the mind of the reader.

It gives connotative meaning to words. The following are types of 

figures of speech.

Metaphor

Oxymoron

Paradox

Simile

Personification

Synedoche

Irony

Hyperbole

Euphemism.

Metaphor :it is the commonest figure  of speech. It can also be referred to  as the sole of words .

It involves a direct  comparison between two things that are not alike but have something  in common.

Examples  of metaphor. Peter holds the  key to her heart

Austin  is a lion

The car thundered by.

Oxymoron :This involves the usage of contradictory items or terms to describe situation or incident.

Examples  of oxymoron

Bittersweet

True lies

joyful sorrow

Sweet pain

Personification :it is all about  adding a human trait or attribute to an inanimate object.

Examples of personification

She kissed the hands of death

The trees sang for joy

Let the floods clap their hands

 Synedoche :This is a figure of speech  in which a path is made to stand for  the whole.

Examples of synedoche

All hands must be on deck

He has many mouths to feed

Simile:This is an indirect comparison  between two things that are not related with words such as like and as

Examples of simile

The man is as old as the hills

Amanda is as slippery as an eel

His head is like a coconut

     .

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parts of speech

                        

            PART OF SPEECH

Part of speech refers to classes of word as determined by the kind of roles the play in a sentence. Every word has a given  functional identity.

Words are grouped  into classes to show  their  grammatical function. There are(8) families of word that form this community  called part of  speech. This  families are grouped into (2) called  the lexical or content word and structural or function word.

Lexical or content word :the are those 

words that has denotative meaning. Under lexical word we have noun, verb, adverb, adjectives.

Functional or structural  words :the do not have dictionary meaning. Under structural  we have  pronoun ,preposition, interjection, conjunction.

                        Noun

A  noun is a name of  a person,  animal ,place or thing, quality, emotion.

          Function of  a noun

.1. Noun plays the role of a subject,object.

2. It can function as a compliment.

                        VERB

A verb is an action  word or a state of being. Verb can be sub divided into two major  part  which are.

* finite verb : the  are controlled by the subject

* non finite verb

      ADVERB

An adverb  modifies  a verb, an adjective and other adverb.

           ADJECTIVES

Adjectives are word that modifies  a noun.

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petroleum

petroleum

What is petroleum? It is a black viscous  liquid mixture which is present  in rock strata and can be extracted and refined to produce fuel, kerosene, diesel.

           FORMATION OF PETROLEUM

Petroleum  was formed  over millions of years by decomposition  of millions  of dead microscopic marine algae, animals and plants which under great pressure heat and bacterial activity is converted to crude oil and natural gases. 

    COMPOSITION OF PETROLEUM

*Natural gases contains many methane and some ethane, propane and butane while  crude oil contains  alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, sulphur, nitrogen compound, oxygen compound, halogen. 

Types of crude oil

Crude oil can be classified by their density or by their sulphur content. 

We have 

*crude oil with low sulphur and it is said to  be sweet 

*crude oil with high sulphur and it is said to be soured. 

We also have light crude, medium crude,heavy crude ,extra heavy. 

Light crude contains  31.1

Medium crude  between 22.3& 31

Heavy crude 22.0

Extra heavy 10.0

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Study skills

Study skills

Study skills involve reading and listening .

     A good approach  to studies will enhance  appreciation  and understanding of the material  read .

That is to say that comprehension is a key to effective studies. There are various  types  of skills  which  a student  can apply in order to have effective  studies, the include

1. Reading skills :  Here the student  is expected to be able to locate any information he seeks in a textbook,by going through its Table of contents,  usually found at the beginning of a book.

2.Listening skills: Good  listening  entails  paying attention to what one hears and think about it in order to assimilate the information or knowledge  being imparted.

two ways of improving your listening skills

* the material needed for a given lecture, have to be ready  before  the stated time for the lecture so that the moment it starts, you are ready for the information being given.

* Noise is a barrier  to effective listening.it must be avoided.

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