Category Archives: General Biology

Keanekaragaman Hayati

 

Di antara (ayat-ayat) tanda-tanda-Nya ialah menciptakan langit dan bumi dan makhluk-makhluk yang melata Yang Dia sebarkan pada keduanya. Dan Dia Maha Kuasa mengumpulkan semuanya apabila dikehendaki-Nya. (QS Asy SYura (42):29)

A. Konsep Keanekaragaman Hayati

Setiap makhluk hidup mempunyai sifat yang sama atau berbeda dengan makhluk hidup lainnya. Keaneka-ragaman hayati terbentuk akibat adanya keseragaman dan keberagaman sifat atau ciri makhluk tersebut. Jadi, keanekaragaman hayati adalah keanekaragaman makhluk hidup yang menunjukkan keseluruhan variasi gen, spesies, dan ekosistem di suatu daerah.

Penyebab keanekaragaman hayati ada dua faktor, yaitu faktor genetik dan faktor luar. Faktor genetik bersifat relatif konstan atau stabil pengaruhnya terhadap morfologi (fenotipe) organisme. Sebaliknya, faktor luar relatif labil pengaruhnya terhadap morfologi (fenotipe) organisme.

Keanekaragaman hayati terbagi menjadi tiga tingkat yaitu keanekaragaman gen, keanekaragaman jenis, dan keanekaragaman ekosistem.

1. Keanekaragaman Gen
Keanekaragaman gen adalah keanekaragaman individu dalam satu jenis makhluk hidup. Keanekaragaman gen mengakibatkan variasi antarindividu sejenis, misal keanekaragaman gen pada manusia.

Keanekaragaman gen pada manusia dapat terlihat pada perbedaan sifat antara lain warna mata (biru, hitam, dan cokelat), ukuran tubuh, warna kulit (hitam, putih, sawo matang, dan kuning), serta bentuk rambut (lurus, ikal, dan keriting). Keanekaragaman sifat tersebut
disebabkan oleh pengaruh perangkat pembawa sifat yang disebut gen.

image

Dan di antara tanda-tanda kekuasaan-Nya ialah menciptakan langit dan bumi dan berlain-lainan bahasamu dan warna kulitmu. Sesungguhnya pada yang demikan itu benar-benar terdapat tanda-tanda bagi orang-orang yang mengetahui. (QS Ar Ruum: 22)

Gb. Keanekaragaman Gen pada Manusia

Continue reading

Nama Ilmiah Flora dan Fauna Indonesia

Prinsip  yang perlu diperhatikan dalam sistem klasifikasi yaitu pemberian nama ilmiah pada makhluk hidup. Pemberian nama ilmiah makhluk hidup ini dikenal dengan  binomial nomenclature. Binomial nomenclature artinya pemberian nama ilmiah makhluk hidup dengan dua kata. Kata pertama menunjukkan genus (marga), sedangkan kata kedua menunjukkan spesies (jenis).

Ketentuan-ketentuan yang harus dipenuhi dalam menulis nama ilmiah makhluk hidup dengan sistem tata nama binomial sebagai berikut.
1. Nama Jenis ( Species )
Nama jenis untuk hewan maupun tumbuhan harus terdiri atas dua kata tunggal (mufrad) yang sudah dilatinkan. Contoh nama jenis tanaman jagung yaitu  Zea mays. Nama jenis burung merpati yaitu  Columbia livia. Kata pertama merupakan nama marga (genus), sedangkan kata kedua merupakan penunjuk spesies atau jenis. Dalam penulisan nama marga, huruf pertama dimulai dengan huruf besar. Adapun nama penunjuk jenis seluruhnya menggunakan huruf kecil. Selanjutnya, setiap nama jenis (spesies) makhluk hidup ditulis dengan huruf cetak miring atau digarisbawahi agar dapat dibedakan dengan nama atau istilah lain.

2. Nama Marga (Genus)
Nama marga tumbuhan maupun hewan terdiri atas suku kata yang merupakan kata benda berbentuk tunggal (mufrad). Huruf pertamanya ditulis dengan huruf besar dan dicetak miring. Contoh marga tumbuhan Solanum  (terung-terungan) dan marga hewan  Felis (kelompok kucing).

3. Nama Suku ( Familia)
Nama suku pada umumnya merupakan suku kata sifat yang dijadikan sebagai kata benda berbentuk jamak. Nama suku berasal dari nama marga makhluk hidup yang bersangkutan. Pada tumbuhan, nama marga ditambahkan akhiran – aceae . Contoh nama suku Solanaceae berasal dari kata Solanum +  aceae . Pada hewan, nama marga ditambahkan dengan –idae . Contoh nama suku Felidae, berasal dari kata Felis + idae .

Menurut sistem binomial nomenklatur, nama penemu suatu spesies (author ) dicantumkan di belakang nama spesies. Nama penemu tersebut dapat disingkat huruf depannya saja. Contoh  Mangifera indica L. (L. merupakan singkatan dari nama penemunya yaitu Linnaeus).

Berikut nama-nama ilmiah dari beberapa flora dan fauna di Indonesia.

Fauna Indonesia

No. Nama Hewan                        Nama Latin
1. Harimau jawa            :              Panthera tigris sondaicus
2. Harimau bali ( punah):         Panthera tigris balica
3. Harimau sumatra:                  Panthera tigris sumatrae
4. Jalak bali putih :                     Leucopsar rothschildi
5. Badak bercula satu :              Rhinoceros sondaicus
6. Binturung :                                Arctictis binturong
7. Monyet:                                     Presbytis thomasi
8. Tarsius :                                    Tarsius bancanus
9. Kukang:                                     Nyoticebus coucang
10. Maleo:                                     Macrocephalon maleo
11. Komodo:                                Varanus komodoensis
12. Burung cenderawasih :     Paradisaea sp.
13. Anoa    :                                   Bubalus depressicornis
14. Babi rusa:                              Babyrousa babyrussa
15. Orang utan  :                        Pongo pygmaeus
16. Kucing emas:                      Catopuma temminckii
17. Tapir:                                     Tapirus indicus
18. Ular sanca hijau                 Morelia viridis

Flora Indonesia

No.    Nama Tumbuhan               Nama Latin
1. Cempaka kuning                       Michelia champaca
2. Damar putih                               Agathis borneensis
3. Kayu manis                                 Cinnamomum burmannii
4. Sapu tangan                                Manilca schefferi
5. Pinang merah                            Areca vestiaria
6. Puspa                                            Schima wallichii
7. Waru                                             Hibiscus tiliaceus
8. Duku                                             Lansium domesticum
9. Pulai                                              Alstonia scholaris
10. Melinjo                                      Gnetum gnemon
11. Menteng                                    Baccaurea racemosa
12. Sempur                                      Dillenia aurea
13. Kepel                                          Stelechocarpus burahol
14. Mundu                                       Garcia dulcis
15. Nyamplung                              Calophylum inophyllum
16. Keben                                         Baringtonia asiatica
17. Palawija                                    Kepsia singa-porensis
18. Majegau                                    Disoxylum densiflorum
19. Ketapang                                  Terminalis catappa
20. Meranti                                    Shorea sp.

Biology as a Science

Biologists apply the methods of science to arrive at an understanding of living organisms. Within the context of biology, it is useful to regard life as complex matter that is susceptible to analysis by chemical and physical approaches. Although there are many phenomena within living systems that appear to lie beyond this mechanistic approach, biologists have been most successful at reaching an understanding of life by focusing on those processes involving transformations of matter and energy.

 

image

source: www.prisonplanet.com

A living organism may thus be defined as a complex unit of physicochemical materials that is capable of self-regulation, metabolism, and reproduction. Furthermore, a living organism demonstrates the ability to interact with its environment, grow, move, and adapt.

 

Biologists cannot study all of life in their own lifetimes. Therefore, they divide the vastness of the living world into many different kinds of organisms and may combine their investigations to a particular type of organism or, alternatively, may study particular aspects of different kinds of organisms and their interactions with one another.

For example  Entomologists, specialists in insect biology, devote their efforts to understanding the various facets of insects but do not become involved with other kinds of organisms. On the other hand, developmental biologists investigate the characteristics of embryo development in many different kinds of organisms but do not venture into investigating other areas.

The boundaries that mark these different areas of investigation provide biology with its specific disciplines, but these boundaries are in a constant state of  flux.

 

Science Method

Science is an organized system for the systematic study of particular aspects of the natural world. The scope of science is limited to those things that can be apprehended by the senses (sight, touch, hearing, etc.). Generally, science stresses an objective approach to the phenomena that are studied. Questions about nature addressed by scientists tend to emphasize how things occur rather than why they occur.

It involves the application of the scientific method to problems formulated by trained minds in particular disciplines. In the broadest sense, the scientific method refers to the working habits of practicing scientists as their curiosity guides them in discerning regularities and relationships among the phenomena they are studying.

A rigorous application of common sense to the study and analysis of data also describes the methods of science. In a more formal sense, the scientific method refers to the model for research developed by Francis Bacon (1561–1626). This model involves the following sequence:

  1. Identifying the problem
  2. Collecting data within the problem area (by observations, measurements, etc.)
  3. Sifting the data for correlations, meaningful connections, and regularities
  4. Formulating a hypothesis (a generalization), which is an educated guess that explains the existing data and suggests further avenues of investigation
  5. Testing the hypothesis rigorously by gathering new data
  6. Confirming, modifying, or rejecting the hypothesis in light of the new findings

Scientists may be interested in different aspects of nature, but they use a similar intellectual approach to guide their investigations. Scientists must ?rst formulate a problem to which they can then seek an answer. The answer generally involves an explanation relating to order or process in nature. The scientist is primarily interested in the mechanisms by which the natural world works rather than in questions of ultimate purpose.

Once a question has been raised, the scientist seeks answers by collecting data relevant to the problem. The data, which may consist of observations, measurements, counts, and a review of past records, are carefully sifted for regularity and relationships.

An educated guess, called a hypothesis, is then drawn up; this places the data into a conceptual framework. The hypothesis makes up the lattice-work upon which scientific understanding is structured. Often called an ‘‘educated guess,’’ the hypothesis constitutes a generalization that describes the state of affairs within an area of investigation. The formulation of fruitful hypotheses is the hallmark of the creative scientific imagination. Inductive logic is used to formulate a hypothesis.

In logic, induction usually refers to a movement from the particular to the general. Thus, the creation of a hypothesis (a generalization) from the particulars (specifics) of the data constitutes an inductive leap within the scientific method. Since the scientific method involves such an inductive process at its very core, it is often described as the inductive method. It is of considerable historic interest that Bacon, who first developed what we now call the scientific method, was extremely suspicious of the inductive step for the development of hypotheses.

He thought that  with the garnering of sufficient data and the establishment of a large network of museums, the hidden truths of nature would be apparent without invoking induction.

EXAMPLE : A man takes up bird watching and has occasion to observe mated pairs of many different kinds of birds. The man repeatedly sees only the drabber bird of any given pair lay eggs. From these observations, the man concludes that all male birds are colorful and all female birds are drab.
A hypothesis must be both logical and testable. Although the conclusion in Example below demonstrates the use of inductive logic, the conclusion cannot be tested and so, as stated, is useless as a scientific hypothesis.

Deductive logic, in which the thought process is from the general to the specific, is used to state a hypothesis that can be tested. The ‘‘If . . . , then . . . ’’ format is often used for this.

EXAMPLE 2: The conclusion in the previous example could be restated as: If birds of a particular species (i.e., birds capable of interbreeding to produce viable young) differ in color, then the more colorful ones are the males.*

After a workable hypothesis has been formulated, it is tested by constructing experiments and gathering new data, which in the end will either support or refute the hypothesis. Note: The application of the scientific method can be used to disprove a hypothesis, but it can never prove anything absolutely. Hence,a hypothesis that withstands the rigors of today’s tests may have to be altered in the light of tomorrow’s evidence.

An experiment must be so structured that the data gathered are free of bias and sampling error. Therefore, the validity of an experiment depends on a careful selection of organisms for the control and experimental groups, so that differences in age, genetic factors, previous treatment, etc., will not influence the results. Adequate numbers of individuals within each group are also crucial, since with small groups, individual peculiarities may be magnified. In addition, an experiment must be reproducible—i.e., other scientists must be able to repeat the experiment and get the same results.