Sabtu, 29 Januari 2011

6 Anti Virus Buatan Indonesia

Antivirus merupakan obat atau sebagai antisipasi dari serangan virus komputer supaya virus tersebut tidak menginfeksi komputer yang dapat berakibat fatal bagi komputer anda, pasti hal ini sangat menjengkelkan bagi kalian, karena data penting yang kalian miliki bisa hilang atau dihapus oleh virus, tapi hal ini hanya berlaku bagi kalian yang masih menggunakan OS Windows dan bukan Open Source seperti linux, namun bagi anda yang masih setia menggunakan OS windows maka diwajibkan untuk memakai antivirus yang tentunya bisa melindungi komputer anda dari serangan virus, trojan, worm, phising, dll. Berikut dibawah ini daftar Antivirus Buatan Indonesia yang paling banyak digunakan di Indonesia : 
1. PC Media Antivirus
PCMAV adalah Antivirus yang dibuat oleh majalah PCmedia yang dimulai pada awal tahun 2006, antivirus ini merupakan antivirus yang paling banyak digunakan di Indonesia, mengingat kemampuannya yang sangat bagus dan sangat membantu sekali, terutama ketika komputer terinfeksi virus, kalian dapat menggunakan pcmav v4lkyr13 untuk membasmi virus/worm yang bernama win32 heur/ win32 cekar, karena antivirus yang cocok untuk menghapus virus/worm tersebut adalah pcmav. Kelemahannya hanya pada waktu scanning yang lama dan tidak bisa digunakan pada OS windows 98 harus windows 2000 keatas.

2. SMADAV

SMADAV adalah antivirus buatan Indonesia yang mulai diluncurkan pada bulan Maret 2007 dan mulai booming pada awal bulan tahun 2009, pengguna smadav pun semakin bertambah itu semua tidak terlepas oleh upaya smadav untuk memperbaharui antivirusnya, keunggulan antivirus ini adalah cepatnya proses scanning pada komputer dan tidak membebani memori komputer, selain itu smadav juga membersihkan hingga tuntas semua virus yang sudah menginfeksi komputer anda dan saat ini smadav mampu mendeteksi kurang lebih 1500 lokasi registry, dan kekurangannya belum bisa menghapus secara tuntas virus-virus impor, karena difokuskan untuk menghadapi virus yang tersebar di Indonesia.

3. ANSAV Antivirus

ANSAV adalah antivirus yang dibuat oleh perusahaan Indonesia yang mulai dipopulerkan sejak bulan Oktober 2006 dan merupakan pesaing dari Antivirus PCMAV yang terlebih dahulu telah diluncurkan. Antivirus ini juga cukup banyak digunakan oleh orang Indonesia terutama untuk membasmi virus brontok, antivirus ini mempunyai kelebihan yaitu sangat sensitif terhadap virus yang telah menginfeksi komputer namun sekaligus terdapat kekurangan yaitu kadang-kadang data yang sudah terinfeksi virus akan ikut terhapus bersama dengan virusnya.

4. Blue Atom Antivirus

Blue Atom Antivirus merupakan antivirus yang dibuat oleh anak kelas IX E SMP Katolik Stella Maris, Surabaya, yang bernama Alvin Leonardo yang masih berusia 14 Tahun, antivirus buatannya ini sudah mendapatkan garansi 100% Clean dari Softpedia.com pada tanggal 19 Oktober 2009, yang membuat kaget adalah Alvin ini tidak melakukan kursus atau bimbingan bahasa pemrograman untuk membuat antivirus ini, tapi dia belajar secara otodidak dengan mempelajari 3 bahasa pemrograman sekaligus yaitu Visual Basic, C#, dan Assembler (ASMX 86), dan menurut pakar IT yang juga Dekan FTIf ITS Prof Drs Ec Ir Riyanarto Sarno MSc PhD mengatakan bahwa Alvin ini akan diikutkan pada lomba-lomba pemrograman dan potensinya bisa dibina untuk menjadi Hacker ilmu putih (WhiteHat).

5. GUCUP Antivirus (GAV)

GUCUP Antivirus merupakan salah satu karya anak bangsa yang sudah dikenal Indonesia bahkan dunia Internasional, Antivirus ini dibuat oleh Yusuf Theretsa Patiku, mahasiswa Program Studi Teknik Informatika, Universitas Atma Jaya Yogyakarta. GAV ini dibuat dengan Microsoft Visual Studio .Net 2003 dengan bahasa pemrograman C#, Antivirus ini juga sudah mendapat garansi 100% clean dari Softpedia.com dan bisa langsung di download disana, kelebihan dari antivirus ini adalah mampu menscan file arsip seperti rar maupun zip, memory system scanning, proses scanning cepat, mampu memisahkan file document yang sudah terinfeksi malware (for : Backdoor.Win32.Delf.axz, Trojan.Win32.Delf.aav, Worm.Win32.Delf.cd) dan mampu memisahkan file aplikasi/.exe dari malware (for : DeulleDo-X [2], Virus.Win32.Delf.bk). Dan masih banyak lagi fitur menarik dari Antivirus ini.

6. AVIGEN Antivirus

AVIGEN Antivirus merupakan antivirus buatan Indonesia yang mempunyai website di www.vibi-bego.com kelebihan dari antivirus ini adalah bisa mencari file-file yang sudah terinfeksi virus seperti worm, hacktool, exploit script, serta trojan horse. Fasilitas yang terdapat pada AVIGEN adalah registry tweak, scan running proses, process viewer, scan autorun location dan masih banyak lagi. Selain itu Antivirus ini juga sudah mendapatkan sertifikat 100% clean dari softpedia.com

Materi Kelas 8 - Getaran dan Gelombang

Gelombang didefinisikan sebagai energi getaran yang merambat. Dalam kehidupan sehari-hari banyak orang berfikir bahwa yang merambat dalam gelombang adalah getarannya atau partikelnya, hal ini sedikit tidak benar karena yang merambat dalam gelombang adalah energi yang dipunyai getaran tersebut. Dari sini timbul benarkan medium yang digunakan gelombang tidak ikut merambat? padahal pada kenyataannya terjadi aliran air di laut yang luas.

Menurut aliran air dilaut itu tidak disebabkab oleh gelombang tetapi lebih disebabkan oleh perbedaan suhu pada air laut. Tapi mungkin juga akan terjadi perpindahan partikel medium, ketika gelombang melalui medium zat gas yang ikatan antar partikelnya sangat lemah maka sangat dimungkinkan partikel udara tersebut berpindah posisi karena terkena energi gelombang. Walau perpindahan partikelnya tidak akan bisa jauh tetapi sudah bisa dikatakan bahwa partikel medium ikut berpindah.
Gelombang berdasarkan mediumnya dibedakan menjadi 2 macam
  • Gelombang mekanik yaitu gelombang yang dalam perambatannya membutuhkan medium. Contoh gelombang mekanik adalah gelombang bunyi.
  • Gelombang elektromagnetik yaitu gelombang yang dalam perambatannya tidak membutuhkan medium. Contoh gelombang elekromagnetik adalah gelombang cahaya.
Gelombang berdasarkan arah rambatnya dibedakan menjadi 2 macam
  • Gelombang Longitudinal adalah gelombang yang arah rambatnya sejajar dengan arah getarnya. Contohnya adalah gelombang bunyi.
  • Gelombang Transversal adalah gelombang yang arah rambatnya tegak lurus dengan arah getarnya. Contohnya gelombang cahaya.
Besaran dalam gelombang hampir sama dengan besaran dalam getaran. Besarannya adalah sebagai berikut ini:
  1. Periode (T) adalah banyaknya waktu yang diperlukan untuk satu gelombang.
  2. Frekuensi (f) adalah banyaknya gelombang yang terjadi dalam waktu 1 sekon.
  3. Amplitudo (A) adalah simpangan maksimum suatu gelombang.
  4. Cepat rambat (v) adalah besarnya jarak yang ditempuh gelombang tiap satuan waktu.
  5. Panjang gelombang (λ) adalah jarak yang ditempuh gelombang dalam 1 periode. Atau besarnya jarak satu bukit satu lembah.
Persamaan yang digunakan dalam gelombang adalah sebagai berikut :
T = t/n
f = n/t
dan
T = 1/f
f = 1/T
dimana : T adalah periode (s)
t adalah waktu (s)
n adalah banyaknya gelombang (kali)
f adalah frekuensi (Hz)
Dari gambar disamping dikatakan benda mengalami satu getaran adalah benda bergerak dari A-B-A-C-A atau B-A-C-A-B
C-A-B = 1/2 getaran
C-A, A-B = 1/4 getaran
Untuk menentukan cepat rambat gelombang digunakan persamaan ;
v = λ.f atau v = λ/T
Dimana λ ( lamda ) adalah panjang gelombang (m)
v  adalah cepat rambat gelombang (m/s)

Jumat, 28 Januari 2011

Materi Dasar Bahasa Inggris - Grammar

Present Continuous



FORM :

subject + to be ( is, am, are ) + be

Examples:
  • You are watching TV.
  • Are you watching TV?
  • You are not watching TV.

USE 1 Now

Use the Present Continuous with normal verbs to express the idea that something is happening now, at this very moment. It can also be used to show that something is not happening now.
Examples:
  • You are learning English now.
  • You are not swimming now.
  • Are you sleeping?
  • I am sitting.
  • I am not standing.
  • Is he sitting or standing?
  • They are reading their books.
  • They are not watching television.
  • What are you doing?
  • Why aren't you doing your homework?

USE 2 Longer Actions in Progress Now

In English, "now" can mean: this second, today, this month, this year, this century, and so on. Sometimes, we use the Present Continuous to say that we are in the process of doing a longer action which is in progress; however, we might not be doing it at this exact second.
Examples: (All of these sentences can be said while eating dinner in a restaurant.)
  • I am studying to become a doctor.
  • I am not studying to become a dentist.
  • I am reading the book Tom Sawyer.
  • I am not reading any books right now.
  • Are you working on any special projects at work?
  • Aren't you teaching at the university now?

Simple Present



FORM

[VERB] + s/es in third person
Examples:
  • You speak English.
  • Do you speak English?
  • You do not speak English.

USE 1 Repeated Actions

Use the Simple Present to express the idea that an action is repeated or usual. The action can be a habit, a hobby, a daily event, a scheduled event or something that often happens. It can also be something a person often forgets or usually does not do.
Examples:
  • I play tennis.
  • She does not play tennis.
  • Does he play tennis?
  • The train leaves every morning at 8 AM.
  • The train does not leave at 9 AM.
  • When does the train usually leave?
  • She always forgets her purse.
  • He never forgets his wallet.
  • Every twelve months, the Earth circles the Sun.
  • Does the Sun circle the Earth?

USE 2 Facts or Generalizations

The Simple Present can also indicate the speaker believes that a fact was true before, is true now, and will be true in the future. It is not important if the speaker is correct about the fact. It is also used to make generalizations about people or things.
Examples:
  • Cats like milk.
  • Birds do not like milk.
  • Do pigs like milk?
  • California is in America.
  • California is not in the United Kingdom.
  • Windows are made of glass.
  • Windows are not made of wood.
  • New York is a small city. It is not important that this fact is untrue.

USE 3 Scheduled Events in the Near Future

Speakers occasionally use Simple Present to talk about scheduled events in the near future. This is most commonly done when talking about public transportation, but it can be used with other scheduled events as well.
Examples:
  • The train leaves tonight at 6 PM.
  • The bus does not arrive at 11 AM, it arrives at 11 PM.
  • When do we board the plane?
  • The party starts at 8 o'clock.
  • When does class begin tomorrow?

USE 4 Now (Non-Continuous Verbs)

Speakers sometimes use the Simple Present to express the idea that an action is happening or is not happening now. This can only be done with non-continuous verb and certain mixed verbs.
Examples:
  • I am here now.
  • She is not here now.
  • He needs help right now.
  • He does not need help now.
  • He has his passport in his hand.
  • Do you have your passport with you?

ADVERB PLACEMENT

The examples below show the placement for grammar adverbs such as: always, only, never, ever, still, just, etc.
Examples:
  • You only speak English.
  • Do you only speak English?

ACTIVE / PASSIVE

Examples:
  • Once a week, Tom cleans the car. Active
  • Once a week, the car is cleaned by Tom. Passive 

Simple Past



FORM

[VERB+ed] or irregular verb
Examples:
  • You called Debbie.
  • Did you call Debbie?
  • You did not call Debbie.

USE 1 Completed Action in the Past


Use the Simple Past to express the idea that an action started and finished at a specific time in the past. Sometimes, the speaker may not actually mention the specific time, but they do have one specific time in mind.

Examples:
  • I saw a movie yesterday.
  • I didn't see a play yesterday.
  • Last year, I traveled to Japan.
  • Last year, I didn't travel to Korea.
  • Did you have dinner last night?
  • She washed her car.
  • He didn't wash his car.

USE 2 A Series of Completed Actions


We use the Simple Past to list a series of completed actions in the past. These actions happen 1st, 2nd, 3rd, 4th, and so on.

Examples:
  • I finished work, walked to the beach, and found a nice place to swim.
  • He arrived from the airport at 8:00, checked into the hotel at 9:00, and met the others at 10:00.
  • Did you add flour, pour in the milk, and then add the eggs?

USE 3 Duration in Past


The Simple Past can be used with a duration which starts and stops in the past. A duration is a longer action often indicated by expressions such as: for two years, for five minutes, all day, all year, etc.

Examples:
  • I lived in Brazil for two years.
  • Shauna studied Japanese for five years.
  • They sat at the beach all day.
  • They did not stay at the party the entire time.
  • We talked on the phone for thirty minutes.
  • A: How long did you wait for them?
    B: We waited for one hour.

USE 4 Habits in the Past


The Simple Past can also be used to describe a habit which stopped in the past. It can have the same meaning as "used to." To make it clear that we are talking about a habit, we often add expressions such as: always, often, usually, never, when I was a child, when I was younger, etc.

Examples:
  • I studied French when I was a child.
  • He played the violin.
  • He didn't play the piano.
  • Did you play a musical instrument when you were a kid?
  • She worked at the movie theater after school.
  • They never went to school, they always skipped class.

USE 5 Past Facts or Generalizations


The Simple Past can also be used to describe past facts or generalizations which are no longer true. As in USE 4 above, this use of the Simple Past is quite similar to the expression "used to."

Examples:
  • She was shy as a child, but now she is very outgoing.
  • He didn't like tomatoes before.
  • Did you live in Texas when you were a kid?
  • People paid much more to make cell phone calls in the past.

IMPORTANT When-Clauses Happen First

Clauses are groups of words which have meaning but are often not complete sentences. Some clauses begin with the word "when" such as "when I dropped my pen..." or "when class began..." These clauses are called when-clauses, and they are very important. The examples below contain when-clauses.
Examples:
  • When I paid her one dollar, she answered my question.
  • She answered my question when I paid her one dollar.
When-clauses are important because they always happen first when both clauses are in the Simple Past. Both of the examples above mean the same thing: first, I paid her one dollar, and then, she answered my question. It is not important whether "when I paid her one dollar" is at the beginning of the sentence or at the end of the sentence. However, the example below has a different meaning. First, she answered my question, and then, I paid her one dollar.
Example:
  • I paid her one dollar when she answered my question.

ADVERB PLACEMENT

The examples below show the placement for grammar adverbs such as: always, only, never, ever, still, just, etc.
Examples:
  • You just called Debbie.
  • Did you just call Debbie?

ACTIVE / PASSIVE

Examples:
  • Tom repaired the car. Active
  • The car was repaired by Tom. Passive

Present Perfect



FORM

[has/have + past participle]
Examples:
  • You have seen that movie many times.
  • Have you seen that movie many times?
  • You have not seen that movie many times.

USE 1 Unspecified Time Before Now


We use the Present Perfect to say that an action happened at an unspecified time before now. The exact time is not important. You CANNOT use the Present Perfect with specific time expressions such as: yesterday, one year ago, last week, when I was a child, when I lived in Japan, at that moment, that day, one day, etc. We CAN use the Present Perfect with unspecific expressions such as: ever, never, once, many times, several times, before, so far, already, yet, etc.

Examples:
  • I have seen that movie twenty times.
  • I think I have met him once before.
  • There have been many earthquakes in California.
  • People have traveled to the Moon.
  • People have not traveled to Mars.
  • Have you read the book yet?
  • Nobody has ever climbed that mountain.
  • A: Has there ever been a war in the United States?
    B: Yes, there has been a war in the United States.

How Do You Actually Use the Present Perfect?

The concept of "unspecified time" can be very confusing to English learners. It is best to associate Present Perfect with the following topics:

TOPIC 1 Experience

You can use the Present Perfect to describe your experience. It is like saying, "I have the experience of..." You can also use this tense to say that you have never had a certain experience. The Present Perfect is NOT used to describe a specific event.
Examples:
  • I have been to France.
    This sentence means that you have had the experience of being in France. Maybe you have been there once, or several times.
  • I have been to France three times.
    You can add the number of times at the end of the sentence.
  • I have never been to France.
    This sentence means that you have not had the experience of going to France.
  • I think I have seen that movie before.
  • He has never traveled by train.
  • Joan has studied two foreign languages.
  • A: Have you ever met him?
    B: No, I have not met him.

TOPIC 2 Change Over Time

We often use the Present Perfect to talk about change that has happened over a period of time.
Examples:
  • You have grown since the last time I saw you.
  • The government has become more interested in arts education.
  • Japanese has become one of the most popular courses at the university since the Asian studies program was established.
  • My English has really improved since I moved to Australia.

TOPIC 3 Accomplishments

We often use the Present Perfect to list the accomplishments of individuals and humanity. You cannot mention a specific time.
Examples:
  • Man has walked on the Moon.
  • Our son has learned how to read.
  • Doctors have cured many deadly diseases.
  • Scientists have split the atom.

TOPIC 4 An Uncompleted Action You Are Expecting

We often use the Present Perfect to say that an action which we expected has not happened. Using the Present Perfect suggests that we are still waiting for the action to happen.
Examples:
  • James has not finished his homework yet.
  • Susan hasn't mastered Japanese, but she can communicate.
  • Bill has still not arrived.
  • The rain hasn't stopped.

TOPIC 5 Multiple Actions at Different Times

We also use the Present Perfect to talk about several different actions which have occurred in the past at different times. Present Perfect suggests the process is not complete and more actions are possible.
Examples:
  • The army has attacked that city five times.
  • I have had four quizzes and five tests so far this semester.
  • We have had many major problems while working on this project.
  • She has talked to several specialists about her problem, but nobody knows why she is sick.

Time Expressions with Present Perfect

When we use the Present Perfect it means that something has happened at some point in our lives before now. Remember, the exact time the action happened is not important.

Sometimes, we want to limit the time we are looking in for an experience. We can do this with expressions such as: in the last week, in the last year, this week, this month, so far, up to now, etc.

Examples:
  • Have you been to Mexico in the last year?
  • I have seen that movie six times in the last month.
  • They have had three tests in the last week.
  • She graduated from university less than three years ago. She has worked for three different companies so far.
  • My car has broken down three times this week.

NOTICE

"Last year" and "in the last year" are very different in meaning. "Last year" means the year before now, and it is considered a specific time which requires simple past. "In the last year" means from 365 days ago until now. It is not considered a specific time, so it requires Present Perfect.
Examples:
  • I went to Mexico last year.
    I went to Mexico in the calendar year before this one.
  • I have been to Mexico in the last year.
    I have been to Mexico at least once at some point between 365 days ago and now.

USE 2 Duration From the Past Until Now (Non-Continuous Verbs)


With non-continuous verb and non-continuous uses of mixed verbs, we use the Present Perfect to show that something started in the past and has continued up until now. "For five minutes," "for two weeks," and "since Tuesday" are all durations which can be used with the Present Perfect.

Examples:
  • I have had a cold for two weeks.
  • She has been in England for six months.
  • Mary has loved chocolate since she was a little girl.
Although the above use of Present Perfect is normally limited to Non-Continuous Verbs and non-continuous uses of Mixed Verbs, the words "live," "work," "teach," and "study" are sometimes used in this way even though they are NOT Non-Continuous Verbs.

ADVERB PLACEMENT

The examples below show the placement for grammar adverbs such as: always, only, never, ever, still, just, etc.
Examples:
  • You have only seen that movie one time.
  • Have you only seen that movie one time?

ACTIVE / PASSIVE

Examples:
  • Many tourists have visited that castle. Active
  • That castle has been visited by many tourists. Passive

Simple Future



Simple Future has two different forms in English: "will" and "be going to." Although the two forms can sometimes be used interchangeably, they often express two very different meanings. These different meanings might seem too abstract at first, but with time and practice, the differences will become clear. Both "will" and "be going to" refer to a specific time in the future.

FORM Will

[will + verb]
Examples:
  • You will help him later.
  • Will you help him later?
  • You will not help him later.

FORM Be Going To

[am/is/are + going to + verb]
Examples:
  • You are going to meet Jane tonight.
  • Are you going to meet Jane tonight?
  • You are not going to meet Jane tonight.

USE 1 "Will" to Express a Voluntary Action

"Will" often suggests that a speaker will do something voluntarily. A voluntary action is one the speaker offers to do for someone else. Often, we use "will" to respond to someone else's complaint or request for help. We also use "will" when we request that someone help us or volunteer to do something for us. Similarly, we use "will not" or "won't" when we refuse to voluntarily do something.
Examples:
  • I will send you the information when I get it.
  • I will translate the email, so Mr. Smith can read it.
  • Will you help me move this heavy table?
  • Will you make dinner?
  • I will not do your homework for you.
  • I won't do all the housework myself!
  • A: I'm really hungry.
    B: I'll make some sandwiches.
  • A: I'm so tired. I'm about to fall asleep.
    B: I'll get you some coffee.
  • A: The phone is ringing.
    B: I'll get it.

USE 2 "Will" to Express a Promise

"Will" is usually used in promises.
Examples:
  • I will call you when I arrive.
  • If I am elected President of the United States, I will make sure everyone has access to inexpensive health insurance.
  • I promise I will not tell him about the surprise party.
  • Don't worry, I'll be careful.
  • I won't tell anyone your secret.

USE 3 "Be going to" to Express a Plan

"Be going to" expresses that something is a plan. It expresses the idea that a person intends to do something in the future. It does not matter whether the plan is realistic or not.
Examples:
  • He is going to spend his vacation in Hawaii.
  • She is not going to spend her vacation in Hawaii.
  • A: When are we going to meet each other tonight?
    B: We are going to meet at 6 PM.
  • I'm going to be an actor when I grow up.
  • Michelle is going to begin medical school next year.
  • They are going to drive all the way to Alaska.
  • Who are you going to invite to the party?
  • A: Who is going to make John's birthday cake?
    B: Sue is going to make John's birthday cake.

USE 4 "Will" or "Be Going to" to Express a Prediction

Both "will" and "be going to" can express the idea of a general prediction about the future. Predictions are guesses about what might happen in the future. In "prediction" sentences, the subject usually has little control over the future and therefore USES 1-3 do not apply. In the following examples, there is no difference in meaning.
Examples:
  • The year 2222 will be a very interesting year.
  • The year 2222 is going to be a very interesting year.
  • John Smith will be the next President.
  • John Smith is going to be the next President.
  • The movie "Zenith" will win several Academy Awards.
  • The movie "Zenith" is going to win several Academy Awards.

IMPORTANT

In the Simple Future, it is not always clear which USE the speaker has in mind. Often, there is more than one way to interpret a sentence's meaning.

No Future in Time Clauses

Like all future forms, the Simple Future cannot be used in clauses beginning with time expressions such as: when, while, before, after, by the time, as soon as, if, unless, etc. Instead of Simple Future, Simple Present is used.
Examples:
  • When you will arrive tonight, we will go out for dinner. Not Correct
  • When you arrive tonight, we will go out for dinner. Correct

ADVERB PLACEMENT

The examples below show the placement for grammar adverbs such as: always, only, never, ever, still, just, etc.
Examples:
  • You will never help him.
  • Will you ever help him?
  • You are never going to meet Jane.
  • Are you ever going to meet Jane?

ACTIVE / PASSIVE

Examples:
  • John will finish the work by 5:00 PM. Active
  • The work will be finished by 5:00 PM. Passive
  • Sally is going to make a beautiful dinner tonight. Active
  • A beautiful dinner is going to be made by Sally tonight. Passive

Materi Kelas 8 - Sistem Peredaran Darah

Transportasi ialah proses pengedaran berbagai zat yang diperlukan ke seluruh tubuh dan pengambilan zat-zat yang tidak diperlukan untuk dikeluarkan dari tubuh. Alat transportasi pada manusia terutama adalah darah. Di dalam tubuh darah beredar dengan bantuan alat peredaran darah yaitu jantung dan pembuluh darah. Selain peredaran darah, pada manusia terdapat juga peredaran limfe (getah bening) dan yang diedarkan melalui pembuluh limfe. Pada hewan alat transpornya adalah cairan tubuh, dan pada hewan tingkat tinggi alat transportasinya adalah darah dan bagian-bagiannya. Alat peredaran darah adalah jantung dan pembuluh darah.

1. Darah
Bagian-bagian darah
Sel-sel darah (bagian yg padat)
  • Eritrosit (sel darah merah)
  • Leukosit (sel darah putih)
  • Trombosit (keping darah)
sel-darah
sel-darah
Plasma Darah (bagian yg cair)
  • Serum
  • Fibrinogen
Fungsi Darah

Darah mempunyai fungsi sebagai berikut :
1. Mengedarkan sari makanan ke seluruh tubuh yang dilakukan oleh plasma darah
2. Mengangkut sisa oksidasi dari sel tubuh untuk dikeluarkan dari tubuh yang dilakukan oleh plasma darah, karbon dioksida dikeluarkan melalui paru-paru, urea dikeluarkan melalui ginjal
3. Mengedarkan hormon yang dikeluarkan oleh kelenjar buntu (endokrin) yang dilakukan oleh plasma darah.
4. Mengangkut oksigen ke seluruh tubuh yang dilakukan oleh sel-sel darah merah
5. Membunuh kuman yang masuk ke dalam tubuh yang dilakukan oleh sel darah putih
6. Menutup luka yang dilakuakn oleh keping-keping darah
7. Menjaga kestabilan suhu tubuh.

2. Jantung
jantung-manusia

Jantung manusia dan hewan mamalia terbagi menjadi 4 ruangan yaitu: bilik kanan, bilik kiri, serambi kanan, serambi kiri. Pada dasarnya sistem transportasi pada manusia dan hewan adalah sama.
3. Pembuluh Darah

Ada 3 macam pembuluh darah yaitu: arteri, vena, dan kapiler (yang merupakan pembuluh darah halus)

Pembuluh Nadi
  • Tempat Agak ke dalam
  • Dinding Pembuluh Tebal, kuat, dan elastis
  • Aliran darah Berasal dari jantung
  • Denyut terasa
  • Katup Hanya disatu tempat dekat jantung
  • Bila ada luka Darah memancar keluar
Pembuluh Vena
  1. Dinding Pembuluh Tipis, tidak elastis
  2. Dekat dengan permukaan tubuh (tipis kebiru-biruan)
  3. Aliran darah Menuju jantung
  4. Denyut tidak terasa
  5. Katup Disepanjang pembuluh
  6. Bila ada luka Darah Tidak memancar
1. Sistem peredaran darah tertutup dan peredaran darah ganda
Dalam keadaan normal darah ada didalam pembuluh darah, ujung arteri bersambung dengan kapiler darah dan kapiler darah bertemu dengan vena terkecil (venula) sehingga darah tetap mengalir dalam pembuluh darah walaupun terjadi pertukaran zat, hal ini disebut sistem peredaran darah tertutup.
Peredaran darah ganda pada manusia, terdiri peredaran darah kecil (jantung –paru-paru – kembali ke jantung) dan peredaran darah besar (jantung – seluruh tubuh dan kembali ke jantung). Peredaran ini melewati jantung sebanyak 2 kali.

5. Getah Bening
Disamping darah sebagai alat transpor, juga terdapat cairan getah bening. Terbentuknya cairan ini karena darah keluar melalui dinding kapiler dan melalui ruang antarsel kemudian masuk ke pembuluh halus yang dinamakan pembuluh getah bening (limfe)

Penyakit pada Sistem Transportasi
1. Anemia
• Anemia sel sabit merupakan penyakit menurun tak bisa diobati
• Anemia perniosa, rendahnya jumlah eritrosit karena makan kurang vit B12
2. Talasemia
Sel darah merah abnormal,umur lebih pendek,diasesi dengan transfusi darah
3. Hemofili
Darah sulit/tidak bisa membeku
4. varises
Pelebaran pembuluh vena
5. Atherosklerosis
Penyumbatan pembuluh darah oleh lemak
6. Arteriosklerosis
Penyumpatan pembuluh darah oleh zat kapur
7. leukopeni
jumlah sel darah putih kurang dari normal

Materi Kelas 8 - Gerak Pada Tumbuhan


Tumbuhan sebagai mahluk hidup juga melakukan gerak. Namun, gerak yang dilakukan oleh tumbuhan tidak seperti yang dilakukan oleh hewan maupun manusia. Gerakan pada tumbuhan sangat terbatas.
Gerakan yang dilakukan oleh tumbuhan hanya dilakukan pada bagian tertentu. Misalnya bagian ujung tunas, bagian ujung akar, ataupun pada bagian lembar daun tertentu. Pada prinsipnya, gerakan tumbuhan terjadi karena adanya proses pertumbuhan dan adanya kepekaan terhadap rangsang atau irritabilitas yang dimiliki oleh tumbuhan tersebut. Sebagai tanggapan terhadap rangsang terebut, tumbuhan melakukan gerakan yang mungkin menuju kearah rangsang atau menjauhi, atau melakukan gerak tanpa menunjukan arah tertentu. Beberapa jenis gerakan tumbuhan yang tergolong iritabilitas dibedakan menjadi tiga, yaitu tropisme, taksis, dan nasti.

A. Tropis

Tropisme adalah gerakan tumbuhan yang dipengaruhi oleh rangsang dari luar. Rangsang dari luar yang mempengaruhi gerak tumbuhan ada bermacam-macam. Misalnya cahaya, gravitasi, air atau kelembaban, dan sentuhan atau singgungan. Berdasarkan jenis rangsangan tersebut, tropisme dibedakan menjadi fototropisme, geotropisme, hidrotropisme, dan tigmotropisme.

a) Fototropisme adalah gerak bagian tumbuhan yang dipengaruhi oleh rangsang cahaya. Apabila gerak tumbuhan tersebut menuju kearah cahaya, berarti tumbuhan tersebut melakukan gerak fototropisme positif. Apabila gerakan tumbuhan ini menjauhi arah cahaya, maka disebut fototropisme negatif. Contoh gerak fototropisme positif adalah tanaman biji-bijian yang sedang tumbuh tunas.
b) Geotropisme adalah gerakan bagian tumbuhan karena pengaruh gravitasi (gaya tarik) bumi. Apabila arah pertumbuhan tersebut ke atas, maka termasuk geotropisme negatif. Akan tetapi, apabila arah pertumbuhan menuju kebawah berarti termasuk gerak geotropisme positif. Contoh geotropisme positif adalah pertumbuhan akar yang selalu menuju kebawah atau kedalam tanah.
c) Hidrotropisme adalah gerak bagian tumbuhan menuju kearah yang basah atau berair. Arah pertumbuhan menuju temapt yang berair disebut gerka hidrotropisme positif. Apabila araah pertumbuhan tanaman menjauhi tempat yang berair disebut gerakan hidrotropisme negatif. Contoh hidrotropisme positif adalah arah pertumbuhan ujung akar didalam tanah yang selalu menuju ketempat yang mengandung air.
d) Tigmotropisme adalah gerak tumbuhan dari bagian tumbuhan akibat persinggungan. Contohnya sulur markisa dan batang mentimun yang membelit tanaman lain.

B. Taksis

Tumbuhan umumnya hanya mampu melalukan gerak pada sebagian anggota tubuhnya, misalnya akar yang mendekati air atau pucuk yang mendekati cahaya. Namun, pada tumbuhan tingkat rendah mampu melakukan gerak berpindah tempat. Seluruh tubuhnya berpindah. Misalnya, tumbuhan euglena dan bakteri besi. Gerak seluruh tubuh tumbuhan yang disebabkan oleh datangnya rangsang disebut gerak taksis. Berdasarkan rangsang penyebabnya, taksis dibedakan menjadi fototaksis dan kemotaktis. Fototaksis merupakan gerak seluruh tubuh tumbuhan yang disebabkan oleh rangsang cahaya. Misalnya gerakan euglena yang selalu mendekati cahaya.

C. Nasti
Daun putri malu akan menutup apabila disentuh. Dan setelah didiamkan agak lama, daun tersebut akan membuka kembali. Gerak tersebut sebagai tanggapan atas reaksi yang datang dari luar, sedangkan arah gerakannya tidak ditentukan oleh arah datangnya rangsang. Gerakan tersebut disebut gerka nasti.Gerak nasti dibedakan menjadi dua, yaitu seismonasti dan gerak niktinasti. Seismonasti adalah gerak bagian tubuh tumbuhan yang disebabkan oleh rangsang sentuhan. Sedangkan gerak niktinasti adalah gerak tubuh tumbuhan karena adanya rangsang intensitas cahaya yaitu gelap atau terang.