BIO BOTANY [3 Mark each]

The diagnostic features of Liliaceae member:

1. Perennial herbs often with bulbous stem / rhizomes
2. Radical leaves
3. Perianth showy
4. Stamens six
5. Ovary superior

The outer most petal is large called standard petal or vexillum. Lateral 2 petals are lanceolate and curved. They are called wing petals or alae. Anterior two petals are partly fused and are called keel petals or carina which encloses the stamens and pistil.

Cladistics:

1. Cladistics is now the most commonly used and accepted method for creating phylogenetic system of classifications.
2. Cladistics produces a hypothesis about the relationship of organism to predict the morphological characteristics of organism.
3. Cladistics helps to elucidate mechanism of evolution.

Chloroplast, the genes are matK and rbcL.

DNA barcoding is a taxonomic method that uses a very short genetic sequence from a standard part of a genome. The genetic sequence used to identify a plant is known as “DNA tags” or “DNA barcodes”. Paul Hebert in 2003 proposed “DNA barcoding” and he is considered as ‘Father of barcoding’.

RFLP (Restriction Fragment Length Polymorphism): RFLP’s is a molecular method of genetic analysis that allows identification of taxa based on unique patterns of restriction sites in specific regions of DNA. It refers to differences between taxa in restriction sites and therefore the lengths of fragments of DNA following cleavage with restriction enzymes.

The uses of molecular taxonomy:

1. Molecular taxonomy helps in establishing the relationship of different plant groups at DNA level.
2. It unlocks the treasure chest of information on evolutionary history of organisms.

Molecular Taxonomy is the branch of phylogeny that analyses hereditary molecular differences, mainly in DNA sequences, to gain information and to establish genetic relationship between the members of different taxonomic categories.

The classification of very similar plants by means of differences in the proteins they contain, to solve taxonomic problems is called serotaxonomy.

The chemical characters can be divided into three main categories:

1. Easily visible characters like starch grains, silica etc.
2. Characters detected by chemical tests like phenolics, oil, fats, waxes etc.
3. Proteins

Plants with incomplete flowers either apetalous or with undifferentiated calyx and corolla are placed under Monochlamydeae. The sepals and petals are not distinguished and they are called perianth. Sometimes both the whorls are absent. Monochlamydeae includes 8 series and 36 families.

Linnaeus classification is mostly based on sexual characters like number, union, length and distribution of stamens and also on carpel characters. Hence it is called sexual system of classification.

Classification is essential to biology because there is a vast diversity of organisms to sort out and compare. Unless they are organized into manageable categories it will be difficult for identification.

The classification of organisms:

1. Understanding the classification of organisms can gives an insight into other fields and has significant practical value.
2. Classification helps us to know about different taxa, their phylogenetic relationship and exact position.
3. It helps to train the students of plant sciences with regard to the diversity of organisms and their relationship with other biological branches.

Preparation of herbarium specimen includes the following steps.

1. Plant Collection
2. Documentation of field site data
3. Preparation of plant specimen
4. Mounting herbarium specimen
5. Herbarium labels
6. Protection of herbarium sheets against mold and insects

binomial nomenclature, the first one is called genus name and second one is specific epithet. Example: Mangifera indica, Mangifera is a genus name and indica is specific epithet.

Taxonomy:

1. Discipline of classifying organisms into taxa
2. Governs the practices of naming, describing, identifying and specimen preservation.
3. Classification + Nomenclature = Taxonomy

Systematics:

1. Broad field of biology that studies the diversification of species
2. Governs the evolutionary history and phylogenetic relationship in addition to taxonomy
3. Taxonomy + Phylogeny = Systematics

Dichotomous key consists of a sequence of two contrasting statements. A pair of contrasting statements is known as couplet. Each statement is known as lead. The plant is correctly identified with keys by narrowing down the characters found in plant.