Dec 252012

The term bryophyta is derived from two Greek words (Bryon: Moss; phyton: plant). Bryophytes are the simplest group of first land-inhabiting plants that tend to grow best in permanently moist conditions. They are not well adapted to live on land as they lack vascular tissue. It includes liverworts, hornworts and mosses. Bryophytes are commonly known as “Amphibians of Plant Kingdom” because they require external water for fertilization and completion of life cycle. Bryophytes include about 960 genera and 24000 species. They are worldwide in distribution on most parts of the earth wherever there is sufficient moisture to sustain plant life.

The characters of plants lying in Bryophyta are:

  1. Bryophytes mostly grow in moist and shady places. Some species are aquatic e.g. Riella, Ricciocarpus natans and Riccia fluitans. Polytrichum and some other species grow in xerophytic conditions.
  2. The gametophyte bearing the reproductive organs is independent and long lived, while the sporophyte bearing the spores is dependent on the gametophyte and is short lived.
  3. The gametophytic plant body may be thallose (not differentiated into stem and leaf) or foliose (differentiated into rhizoids, stem and leaves).
  4. The vascular tissues are absent. The plant body consists of simple parechymatous cells.
  5. The thalli of primitive forms remain attached to the substratum by unicellular smooth walled or tuberculate rhizoids. However, in higher forms, the rhizoids are branched and multicellular.
  6. In some bryophytes multicellular scales are present, which provide protection to the growing point. For example, Riccia, Marchantia.
  7. Reproduction is brought about by vegetative and sexual means.
  8. Water is essential at the time of fertilization.
  9. The sporophyte of Riccia is very simple; consists of capsule only, whereas in other bryophytes it consists of foot, seta and capsule.
  10. The capsule contains sporogenous tissues which divide meiotically to form four haploid spores.
  11. Spore is the first cell of gametophytic generation, which on germination gives rise to gametophytic plant body.
  12. The life cycle of a bryophyte shows regular alternation of gametophytic and sporophytic generation.
Dec 232012

During these recent years, many improvements and developments in the field of information and technology can be found. Many new electronic gadgets like mobile phones, personal computers, laptop computers, tablet computers, watches etc. were created by different organizations. These all gadgets were well-equipped with different new and attractive features and functions.

One of such electronic gadgets which ruled over the hearts of the people of the whole world is Apple Inc., U.S.A.’s I-Phone. The main factor that made I-Phone that much famous and popular as well as liked was its new, useful and innovative features. After that, another factor that made I-Phone that much liked was its sleek, elegant and unique kind of look. But, the important thing that made I-Phone well-known all over the world is its operating system. Its operating system was unique and efficient that other operating systems of mobile phones. This gave rise to a competition in the software and operating systems of mobile phones.

Nowadays, there is given less priority to hardware rather than software. Today, there is a huge and tight competition between mobile phones in terms of their operating systems (OS). The main factor that dismissed I-Phone from its throne and brought out a new phone, Samsung Galaxy S3 as its new king is the Android Operating System that is used in Samsung Galaxy S3.

Telling the fact, Android is a Linux-based operating system. Google, which has named every upgraded version of its Android Operating System in android botterms of food, has now named Android 4.2 operating system as Jelly Bean. With the new and sweet names of its operating systems, Google has even worked hard to provide more new and exciting features and functions in its Android Operating Systems. Google’s operating systems’ names and their features are attracting the people very much.

While talking about the history of Google’s Android Operating System, we can find that its history is not very much long. But it has released many versions of its operating system. The Android Operating System version 1.0 and 1.1 weren’t publicly given any kind of names. But the versions that were released after them were given special names which were based on the names of sweet and tasty foods. Since the release of Google’s Android Operating System version 1.5, Google started a trend to give names based on the foods in an alphabetical order. Google named Android Operating System version 1.5 as ‘Cupcake’. Likewise, it named its next operating system version 1.6 as ‘Donut’. After ‘Donut’, a new version was released which was named Éclair. This Android Operating System was released in different versions like 2.0, 2.0.1 and 2.1. After that, Frozen Yogurt (Froyo) was released which contained versions like 2.2 and 2.2X. Then, again a new Android version named Gingerbread was released which was Android version 2.3 and 2.3X.

Similarly, in the Honeycomb version there were version 3.0, 3.0 X, 3.1 and 3.2. Likewise, the most widely used version is Ice Cream Sandwich version which is version 4.0, 4.0.1, 4.0.2, 4.0.3 and 4.0.4. This is the Android version used in most of the smartphones of today including famous smartphones like Samsung Galaxy Note.

Likewise, Jelly Bean is the latest version of android which is also called Android version 4.1 and 4.2. This is not that much famous like Ice Cream Sandwich because very less smartphones have this operating system in them. Nexus 7 tablet was the first gadget to have this operating system installed in it.

Now also, people are working in the development of new versions of Android. But to use them, we will have to wait for some time. Till then, lets enjoy the current Android versions.