BIOLOGY NEET NOTES

PART 4

BINOMIAL SYSTEM OF NOMENCLATURE 

It was proposed by GASPARD BAUHIN in  his book "PINAX THEATRI BOTANICA". Linnaeus used his nomenclature system for the first time on a large scale and proposed the  scientific name for all plants and animals. CARL LINNAEUS is also known as founder of binomial system.

Scientific name for plants was given on 1st May 1753 in SPECIES PLANTARUM .

Scientific name for animals was given on 1st August 1758 in SYSTEMA NATURAE 10th edition.

ICBN (INTERNATIONAL CODE OF BOTANICAL NOMENCLATURE)

It is collection of rules regarding scientific nomenclature of plants, fungi and other organisms which are traditionally treated as algae, fungi, or plants. It was first accepted in 1961. Tautonyms are those whose generic and specific names are same. These tautonyms are not allowed in plant nomenclature but in animal nomenclature it is valid. e.g Naja Naja and Rattus Rattus.

ICZN (INTERNATIONAL CODE OF ZOOLOGICAL NOMENCLATURE) 

If specific name is based on name of a scientist/ some person then the first letter should be capital. e.g Isoetes Pantii (quill wort). 

Name of  scientist should be neither underlined nor to be written in italics. Scientific name should be in latin or greek language because they are dead language(no one speaks). 

a old plant species should be placed in herbarium to preserve it.

TRINOMIAL SYSTEM OF NOMENCLATURE 

It was proposed by Huxley and Stricklandt. According to this system the name should be composed of three words: 1] GENERIC NAME, 2] SPECIFIC NAME/ SPECIFIC EPITHET, 3]SUB-SPECIFIC NAME/ NAME OF VARIETY. 

When members of any species have large variations then trinomial system is used. on the basis of this similarities these species are classified into sub species. 

Brassica olrecea botrytis (CAULIFLOWER)

Brassica oleracea capitala (CABBAGE)

Brassica oleracea caulorapa (KNOL KHOL)

Brassica oleracia italica (BROCCOLI)

*All above plants are of the same species but they cannot interbreed so they are one taxonomic category and four biological species. 

ICNB (INTERNATIONAL CODE OF NOMENCLATURE FOR BACTERIA)

ICTV (INTERNATIONAL COMMITTEE FOR TAXONOMY OF VIRUS)

The concept and term was given by John Ray. He described more than 18,000 plants and animals in his book "HISTORIA GENERALIS PLANTARUM" (in the year 1686). Ernst Mayer (Darwin of the 20th century) proposed biological concept of species. He told that organisms which can interbreed among themselves and produce fertile off-springs under natural conditions are called as species but its incomplete because it didn't explain asexual reproduction. e.g bacteria and multiplasma. The main character in determination of any species is interbreeding but this character is not related by taxonomy. In taxonomy the determination of species is based on other species. e.g  MORPHOLOGICAL CHARACTERS. 

In higher plants, the determination of species is mainly based on the morphology of flower because floral characters are are more reliable than vegetative characters as they do not show major changes. *ALL HUMANS ARE ONE BEING* 

SIBLING SPECIES/ CRYPTIC SPECIES  ---> Morphologically similar characters but cannot interbreed

OBLIGATE CATEGORIES

1] KINGDOM ---> KEEP

2] PHYLUM(for PLANTS)/ DIVISION(for ANIMALS) ---> PLACE

3] CLASS ---> CLEAN 

4] ORDER (plants)/ COHORT(animals) ----> OR

5] FAMILY ----> FAMILY 

6] GENUS ----> GETS 

7] SPECIES ----> SICK

KEEP (KINGDOM) PLACE(PHYLUM) CLEAN(CLASS) OR(ORDER) FAMILY(FAMILY) GETS(GENUS) SICK(SPECIES)

Basic unit of classification and smallest taxonomic category. Each category is called taxon. The term taxon was used by Adolf  Mayer for animals and H. I. Lamp for plants.