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Sunday 22 September 2013

Tim Cook joins Twitter, tweets about seeing 'happy customers' at Apple stores

Sunday 22 September 2013 - 0 Comments



Apple chief executive Tim Cook joined Twitter on Friday, as huge crowds formed around the world to buy up the California giant's two new iPhones.

In his first tweet, Cook described his visit to customers waiting for iPhones near the company's headquarters.

"Visited Retail Stores in Palo Alto today. Seeing so many happy customers reminds us of why we do what we do," he wrote.

  The account, featuring a photographic portrait of Cook against a black background, bore the one-to-many microblogging service's standard blue check mark meaning it has been officially confirmed by Twitter.

Cook identified himself as "CEO Apple" and a "Fan of Auburn football and Duke basketball" from Cupertino, California.

And he snapped up a huge following very quickly.

Within just hours of joining the service, Cook had already scored more than 92,000 followers.

And the company also launched the Twitter account @iTunes this week as it unveiled iOS 7, the operating system for the iPhone, iPad and iPod Touch.

Apple is releasing the iPhone 5S, and the lower price 5C this week. While customers in the United States can get the iPhone 5C for $100 with a carrier contract, the unsubsidised price is $549 in the US and higher elsewhere.

Saturday 21 September 2013

How to create websites?

Saturday 21 September 2013 - 1 Comment

How to create websites?



Are you want to create website? but do you have a problem how to start it and what to do to create website? There may lot of confusion going on your mind. Don't be complex. Here I will explain how to create websites? and all things related to it. First of all in your mind, you must know what kind of website you want to create. For instance, music or downloading website, social networking, blogging, forum etc..
  1. Want to create free website/wapsite, go to http://wapka.com , http://wapego.com and http://xtgem.com for creating wapsite. that means mobile sites. if you want to create websites for free go to www.wordpress.com or www.blogger.com etc. or use google to get more free website builder. No domain is required the above websites allow sub-domain so feel free.
  2. Want to create a high level website without any programming knowledge with unlimited bandwidth and diskspace. go to http://godaddy.com or http://hostgator.com etc.. But the only thing is you must pay fees monthly for creating high level websites. Both godaddy and hostgator has website builder so it's easy to create website with godaddy and hostgator without any programming knowledge. Monthly fees is based on your product pack. Remeber you need a domain to run your website. Domain is a name of your website that means web address, For instance, your domain look like www.yourdomain.com.  You must pay yearly for domain name. you may also buy your domains from Godaddy or Hostgator.
  3. Do you know web programming language like HTML, PHP, MySQL, .Net etc. You may also choose http://godaddy.com or http://hostgator.com. They also provide web hosting   with both windows and linux hosting. You must pay monthly for your hosting.
Have any problems or please feel free to post a comment here I will help you to solve it

Friday 23 August 2013

Structure and Classification of Paramecium caudatum

Friday 23 August 2013 - 0 Comments


Paramecium caudatum

Classification:

·         Phylum:            Protozoa
·         Sub Phylum:     Ciliophora
·         Class:               Ciliatea
·         Order:              Hymenostomatida
·         Genus:             Paramecium
·         Species:           caudatum
    
     Paramecium  is well-known ciliate protozoans. It demonstrates  a very high degree of cellular differentiation, exhibiting many complex organelles which have been designed to perform specific functions for the organism. Not only its structure show specialization, but its reproductive activity is also complex. There are about 10 species of Paramecium. Its common species are P.caudatum and P.aurelia.


1.     Habit and Habitat:
                    It’s a free living organism having cosmopolitan (world-wide) distribution. It lives in stagnant water of freshwater, ponds, pools, ditches, lakes and slow flowing rich in decaying organic matter

2.     Structure:

         A: Shape & Size:

                               Paramecium cadatum is a unicellular and microscopic protozoan. It measures 170 to 290 µm up to 300-350 µm. It is visible to the naked eye. Its body has a constant elongated, slipper-like shape, so it’s also called slipper animalcule. Anterior part of the body is blunt and broad and posterior end is thick, pointed and cone shaped, widest part is just below the middle. Body is asymmetrical showing well defined oral or ventral surface and convex dorsal or aboral surface.

         B:Pellicle:

                            The whole body is covered by thin, firm, flexible membrane called pellicle. Pellicle is made up of gelatinous substance. It gives shape of the animal but is elastic to permit contraction.

         C:Cilia:

                           Body is covered by numerous, small hair-like projections called cilia, arranged in longitudinal rows. The length of cilia is uniform throughout the body ( a condition called holotrichous), but there are a few longer cilia at the posterior end of body. These form caudal tuft of cilia (hence the name caudatum). Cilia have the same structure as flagella, an outer protoplasmic sheath or plasma membrane with nine double longitudinal fibrils, in a peripheral ring. Two central fibrils, which are thinner than the outer fibrils. Each cilium arrives from a basal granule. At the base the cilia has a diameter of 0.2 µm (2000 A ̊).

3. Cytostome:

         A: Oral groove:

                         On the ventro-lateral side is a large oblique, shallow depression called oral groove or peristome which gives the animal asymmetrical appearance. The oral groove lends into a short conical funnel shaped depression called vestibule. Vestibule leads to an oval shaped opening called cytostome. It is followed by a long opening  called cytopharynx; which leads to the oesophagous  - that leads to food vacuole.

        B: Cytopyge:

                       The cytopyge or cytoproct lies on the ventral surface, almost vertically behind the cytostome. Undigested food particles are eliminated through the cytopyge.

        C:Cytoplasm:

                       The cytoplasm is differentiated into a narrow peripheral layer of clear and dense plasmegel, called ectoplasm and an inner large central mass of granular and semifluid plasmasol or endoplasm.

        D:Ectoplasm:

                      It forms a firm, clear, thin and dense outer layer. It contains the trichocysts, cilia and fibrillar structures and is bound externally by a covering called pellicle.

        E:Trichocysts:

                      Small spindle shape bags are embedded in the ectoplasm filled with a refractive, dense fluid having swelling substance. At the outer end there is a conical head on spike. Trichocysts lie perpendicular to ectoplasm.

        F:Endoplasm:

                    Endoplasm is the voluminous part of the cytoplasm, contains many granules as well as other structures and inclusions such as mitochondria, vacuoles etc. other students includes nuclei, contractile vacuole, food vacuole etc.

4. Nuclei:

        A:Macro Nucleus:

                       It is a ellipsoidal or kidney like shaped nucleus. Densely packed with chromatin granules (DNA). It is a vegetative nucleus, controls vegetative functions.

        B:Micro Nucleus:

                     Small compact and spherical,  found close to macro nucleus. Fine chromatin granules and threads uniformly distributed throughout the structure. It controls reproduction. Number varies with species to species. Nucleolus is absent in caudatum.

5. Contractile Vacuole:

           There are two fluid filled contractile vacuoles, one each at the ends of the body close to dorsal surface. Their position is fixed between the ectoplasm and endoplasm. They are temporary organs disappearing periodically. Five to twelve radical canals are connected  to each contractile vacuole. Each radial canal consists of a terminal part, a long ampula and a short injector canal which opens into the contractile vacuole. The canal communicate with large part of the body and takes up liquids and pour into the vacuole. Thus the vacuole increase in size and the liquid discharged outside during systole through the permanent opening (pore) in the pelged. The two vacuoles contract irregulargly, the posterior C.V contract more rapidly because it is close to the cytopharynx and more water comes to it. The main function of contracted vacuole is osmoregulation and probably involves respiration and excretion.

6. Food Vacuole:

        Roughly spherical, non contractile lies varying in size and lying in the endoplasm.  They contain digested food particle especially bacteria and small amount of fluid. The digestive granules are associated with the food vacuoles helps in digestion.


Monday 12 August 2013

Phylum Annelida: General Characters

Monday 12 August 2013 - 2 Comments

Phylum Annelida

         Phylum Annelida (L., Annelus = a ring) includes about 12,000 species of segmented coelomate worms. They range from a deep-sea species measuring less than 1 mm in length to giant tropical earthworms (of Australia) Which measure upto 4 m in length. Most annelids are aquatic found in the sea as swimmers, crawlers, burrowers and tube dwellers or in freshwater where they usually burrow. Terrestrial annelids are mostly burrowers and some are parasites. Phylum Annelida comprises three main classes: the Polychaeta (marine), the Oligochaeta (terrestrial and freshwater) and the Hirudinea (terrestrial, marine and freshwater leeches).

          Annelids are soft-bodied, elongated, cylindrical, bilaterally symmetrical, metamerically segmented coelomate worms having a thin covering of cuticle, a dermomuscular body wall and often chitinous setae.


General Characters of Annelida:

  1. Annelids are triploblastic and bilaterally symmetrical coelomates.
  2. Body is soft, elongated, vermiform (worm-like) and metamerically segmented (i.e, body divided into similar parts or segments which are arranged in a linear series along the antero-posterior axis). The segments are marked externally by transverse grooves and internally by transverse septa. Each septum comprises of a layer of connective tissue sandwitched in between two layers of peritoneum.
  3. The head or acron is represented by prostomium and contains the brain. It is pre-oral body part. Terminal part of body is called pygidium and contains anus. Mouth exists in peristomium .
  4. Body wall consists of a fibrous collagenous circle, a glandular epidermis in which the nerve fibres are situated and a connective tissue dermis of varying thickness. Muscles of body wall exists in outer continuous layer of circular muscles(just inner to dermis) and inner layer of longitudinal muscles. The latter is lined by parietal peristoneum (coelomic epithelium). Cuticle is secreted by ectoderm (or epidermis).
  5. The paired appendages if present are not joined.
  6. Locomotory organs are segmentally arranged, paired, chitinous lateral bristles called setae or chaetae. They are absent in leeches.
  7. Body cavity is a true coelom or periviseeral coelom lying between the two layers of mesoderm. Coelom is a schizocoel and divided into segmental compartments by septa.
  8. Alimentary canal is a straight tube running from the anterior mouth to the posterior anus. Digestion is extracellular.
  9. Respiration occurs through general body surface or gills.
  10. Circulatory system or blood vascular system is well developed and closed type. Blood is usually red and contains haemoglobin (a respiratory pigment). Respiratory pigment is often dissolved in the plasma.
  11. Excretory organs are segmental, ectodermal in origin, ciliated, paired and called nephridia (metanephridia and protonephridia).
  12. The nervous system consists of an anterior, dorsal ganglionic mass or brain; a pair of anterior connectives surrounding the gut and a long double or single solid ventral nerve cord with ganglionic swellings and lateral nerves in each segment.
  13. A giant fibre system is used for rapid conduction and evokes fast startle contraction.
  14. Aphrodite and Chaetopterus have no giant fibre system but other annelids including Lumbricus have giant fibre system.
  15. Gonads develop from coelomic epithelium.
  16. Sexes may be united (monoecious or hermaphrodite) or separated (dioecious).
  17. Development is direct (without any larval stage) in monoecious annelids and is indirect (with trochophore larva) in dioecious and aquatic annelids.
  18. Cleavage is spiral and determinate.
  19. Asexual reproduction occurs in some annelids. Power of regeneration of their lost parts occurs in many annelids.
  20. Aquatic or Terrestrial

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