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7.1.2013 - Tarikh pembukaan pembelian no pin upu dan permohonan upu fasa 1 utk pelajar matrikulasi/stpm/setaraf

Biology Chapter 10: Growth

BIOLOGY FOR MATRICULATION

Chapter 10 : Growth

Objective

• to define the term of growth
• to state 3 phases of individual growth
• to explain how growth is measured

Overview

10.1 Growth Phases

10.2 Measurement Of Growth

10.3 Growth Patterns

10.4 Growth Rate 

10.5Growth Under Extreme condition

 10.1 Growth Phases

Definition of Growth

•  any permanent increase in qualitative parameters (can be measured) e.g volume, width, length (height), cell number, dry mass, surface areas
• which is not reversible
• an increse in biomass, length and width over a specific time

Definition of Development

• any qualitative changes e.g function, degree of specialization and complexity
• involve cell differentiation, e.g red blood cell and xylem

Growth in Unicellular Organism

• is restrictive by the size of its cytoplasm that is controlled by its nucleus
• when achieve a certain size, it divides to produce 2 daughter cells of smaller size

to be continue.....

Cellular Radio Network

GSM Cells

Cellular Radio Network

A Cellular Radio Network is a system of land based cells which allows portable transceivers’, such as mobile phones, to communicate with other transceivers over large geographical areas. A Cellular Radio Network allows this to happen even if the transceiver is moving between individual cells. Each of the cells communicates with a base station otherwise known as a cell site.

The advantage of a Cellular Radio Network over a network relying on a single transmitter is the fact that a series of cells can reuse a particular frequency for totally separate transmissions. With a single transmitter, one frequency only can be used to accommodate one transmission. If another adjacent cell uses that frequency, interference may be experienced.

A Cellular Radio Network is therefore split into roughly similar sized and shaped areas and no transmitter will use the same frequency as an adjacent cell. As long as there is at least one cell operating on a different frequency situated between the two transmitters operating on the same frequency, those two cells can operate on that particular frequency without any signal interference.

Mobile phone users are able to move between the cells of a Cellular Radio Network without knowing that they are changing frequencies because the hand-over or handoff system does not need to be manually switched.

The new base station will effectively tell the mobile phone that it needs to switch to a new channel, which it is capable of doing without interruption

Mobile Phone Accessories

The meteoric rise in mobile phone ownership in recent years has led to an equally impressive increase in the number of Mobile Phone Accessories available on the market. These range from the practical: spare batteries and headphones for listening to MP3s, to the decorative: covers and

Network Structure

Mobile phone cellular Network Structure is pretty much what makes up the basis of the GSM system. It has been set up to make sure that customers using their mobile devices are able to do so in the most manageable and efficient way possible. It deals with factors including communication set up, communication registration and the smooth transfer of uninterrupted coverage through the entire cellular Network Structure.

The Network Structure consists of four essential components: radio base stations serving the cellular network; a packet switched network responsible for coping with data coming from mobile devices; a core-circuit switched network which deals with text messages and voice calls; and the public switched network which allows mobile users to communicate with the wider telephone network.

Because there is a finite number of radio frequencies, and because systems other than mobile phone networks use them, the Network Structure requires that a cellular system is used to enable mobile phone companies to serve as many customers as possible without interference being a problem.

The Network Structure is therefore made up of a system of cells which do not function on the same frequency as the cell immediately next to them. However, this does allow for the repeated use of a particular frequency later on in the cell grid.

The range of a typical cell in a built up area is approximately half-a-mile. In more open areas the range of a cell can increase dramatically. In some places the range of a cell in the Network Structure can be as wide

Mobile Phones

Customers looking for GSM (Global System for Mobile Communications) Info can now find all they need to know on a new, dedicated website: gsm-info.org. Although the acronym is now commonly associated with the English description, GSM originally stood for Groupe Special Mobile, the most popular of the world’s mobile phone standards.

A second generation, or 2G, mobile system, GSM set itself apart from other technologies by making both its speech and signalling channels digital. According to GSM (Global System for Mobile Communications) Info figures, around 80 per cent of the world’s mobile users are plugged into the standard.

The great advantage to consumers of GSM is that it allows them to use their mobile technology across different markets without having to purchase new hardware. GSM was also the first system which allowed users to cheaply send text messages, or SMS, to other mobile users.

GSM was created after the European Conference of Postal and Telecommunications Administrations decided that a European standard should be established. In 1987, GSM (Global System for Mobile Communication) Info was sent out to 13 countries and an agreement was signed to establish a common European telecommunication standard.

By 1990, the first set of specifications for a GSM system was published and the following year saw the launch of the first GSM network under the technical supervision of Ericsson. The popularity of the mobile phone then exploded and by the end of 1993 more than one million people had signed up in 48 countries. as 25 miles.

works

Mobile phone Networks are the way in which mobile phone companies make sure that customers are allowed to enjoy mobile technology in a seamless and uninterrupted manner. The basic principle behind cellular Networks is to provide a grid of cells across a large area of land which provides customers with the ability to stay in contact without a break in service.

Networks also have the advantage of being able to re-use individual frequencies without causing any interference to other mobile device operators. They also have the advantage of being able to use computer technology to switch those frequencies in the phone without the owner having to do so manually. As a phone user crosses the boundary between two cells on the radio network, the base station will assign a new frequency. The mobile handset will recognise the frequency and re-tune to it, without any delay in communication.

The size of the cells across Networks varies greatly and depends on factors such as topography. Because it is a radio based system, signals may become blocked by tall buildings, hills or trees.

A second factor influencing the size of a network’s cells is the amount of mobile phone usage in an area. In a city, the space between base stations will typically be no more than 0.5km apart, whereas in the countryside they can be as far as 5km apart.

The other factor governing the spacing of cells in Networks is the frequency of the radio signal. Higher frequencies require smaller cells.

colourful skins.

One essential accessory for the mobile phone is the battery charger. Whether plugged into a wall socket, the cigarette lighter in a car or into a computer; a new agreement by a number of mobile companies to standardise chargers to fit all of their phones will certainly make life easier for the consumer and cut down on the cost of having to give one out with every new phone sold.

Mobile phone accessories producer Parrot claims that currently one in every six mobile phone sales will result in the purchase of an accessory. By next year, the firm believes that this figure will rise to one in three. US president of Parrot, Edward Valdez, said that this will lead to increased competition in the Mobile Phone Accessories market.

Software for mobile devices is also becoming popular with owners. Games are increasingly becoming must have Mobile Phone Accessories and the rise of the iPhone has seen a tremendous demand for apps.

As well as providing entertainment, iPhone apps have quickly been recognised as important marketing tools for many companies who are thinking up more and more ingenious ways of pushing their products at smart phone user.