How to prepare a key, Biology

Assignment Help:

Q. How to Prepare a Key?

Let us prepare a key by making a choice of. characters, listing significant and insignificant characters, tabulating these characters and forming dichotomies. List all the permanent morphological characters and write them in the same sequence on cards. Keep one card for each taxon. If we choose petiole as a character we have to write it at the same number in all the cards. 

289_How to Prepare a Key.png

From the table it. is clear that taxa I, I1 and I11 fall into one group and IV in another. On the basis of characters noted at 1,2 and 3. This is called Dichotomy. On the basis, of perianth character written at No. 4 again two groups are made, one of taxa I. and. I1 and other of taxa I11 and IV. Taxa I and I1 are further separated on the basis of character of petals, free versus connate. Now sort out all the cards into two groups and separate cards of each group into two or more sub groups till all the taxa are dealt with and all the cards are sorted out. All the characters on the basis of which cards are sorted into groups form the couplets of leads. Now print the key and write flower trirnerous and not trimerous flowers and leaves reticulate and not reticulate leaves. f size is a character then give range of measurements and do not use words like big, small large.


Related Discussions:- How to prepare a key

Explain the evolution of the vascular plant body, Explain the Evolution of ...

Explain the Evolution of the Vascular Plant Body? Vascular Plant anatomy reflects adaptation to life on land. In an aquatic environment, the photosynthetic surfaces are support

What is pollen, What is pollen? Pollen grains are the male gametophytes...

What is pollen? Pollen grains are the male gametophytes of the phanerogamic (flowering) plants. Thus within the pollen grains the male gametes of these plants are produced by m

Chemical properties of fatty acids, Chemical Properties of Fatty Acids ...

Chemical Properties of Fatty Acids Esterification Like any other organic acid,  fatty acids also form esters with  various alcohols. An alcohol such as glycerol is reacted

Entomophily - cross-pollination, Entomophily - Cross-pollination It in...

Entomophily - Cross-pollination It involves insects to carry the pollen to achieve pollination. Salvia exhibits a specialised 'tumapipe' floral mechanism that signifies classi

Define the food sources of thiamin, Define the Food Sources of Thiamin? ...

Define the Food Sources of Thiamin? Thiamin is present in many food products and depending on the amount of vitamin present, we have categorized the foods as rich, good or fair

Extremes of heat and cold, Extremes of Heat and Cold Deserts are region...

Extremes of Heat and Cold Deserts are regions of aridity with rainfall of less than 20 cm per year and the soil, though L, fertile, is too porous to retain any water. In summer

Factors that limit the reproductive potential, Organisms are made to compet...

Organisms are made to compete for their needs from the environment. The competition as we pointed earlier could be for the food and territory, to overcome the adverse climatic cond

Distribution coefficient -terminology used in chromatography, Distribution ...

Distribution Coefficient - Terminologies used in Chromatography? During the purification or separation of the biomolecules it should be kept in mind that two important factors

Define etiological risk factors in cancer, Define Etiological Risk Factors ...

Define Etiological Risk Factors in Cancer? Cancer risks are climbing because of increasingly sedentary lifestyles and diets which are high in fat and sugar although low in frui

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd