Selasa, 12 Maret 2013

Virus

VIRUS
-Virus has ultra-microscopic size, about 20-30 milimikron, so it can only be observed with an electron microscope
-Consists of acid core, the DNA or RNA, and capsid (protein coat that gives shape to the virus)
-Viruses can only reproduce inside a living cell or tissue
-The virus is not a cell, so it does not have cytoplasm, nucleus, or nuclear membrane
-The shape is diverse, such as rods, oval, round, and T
-It is a true parasite
-Can be crystallized

Virus body consists of two parts, the head and tail. 
On the head there is :
-Capsid
Namely the wrapping layer virus body composed of protein. In some types of the virus, the capsid is still there next to the outer wrapper composed of lipids and carbohydrates. Capsid serves to give shape to the virus as well as protection from adverse environmental conditions.

-Genetic material
That is the nature of the molecules that are dropped inside the capsid. Genetic material can be either RNA (ribonucleic acid) or DNA (deoxyribonucleic acid). In the body, the virus has only one type of nuclei acid (nucleic acids), which have RNA or DNA alone, never both.

At the tail there is a tail sheath and tail fibers are essential for virus attachment to the host cell body when it will be reproducing.


REFERENSI : Jago Biologi SMA

0 komentar:

Posting Komentar