Question

103-108, What are the 3 major secondary metabolites found in plants, and what are examples of each? Also illustrate their chemistry and list their functions in the space below 109-110. Beginning with the largest taxonomic unit, place the following in correct hierarchical order: phylum, domain, order, genus, species, kingdom, family, elass, subspecies 111-114. What are 5 key evolutionary similarities between the green algae and land plants? 115-117. How do humans use plants? (List 6 uses)

Answer 1

Ans.103-108. Secondary Metabolites:- These are the metabolites intermediates or products which are not essential to growth and life of the plant that produces it but rather the are required for the interaction of plants with thier environment and produced in responses to stress. They are also called as secondary products.

Main features of secondary metabolites are as under:-

1. They are involved in the ecological function such as protection of plants.

2. They are not the part of basic structure of plant.

3. They may be different in different plants.

4. They are produced in small quantities.

5. They are prosuced in stationary phase.

6. They may be poisonous.

Three secondary metabolites found in the plants are .:-

1. Terpenes.

2. Phenolics.

3. Alkaloids.

Terpenes:- they are build up of the isoprene units. They are also known as the isoprenoid compounds. The basic formula of terpene are multiple of (C5H8)n . Here n is the number of the isoprene units. Examples are pyrenoids, limonene, menthol, abscisic acid , taxol, rubber, casbene etc.

Function:- They are mainly involved in the growth and development for example gibberalins. They defends against the herbivores such as pyrethroids etec.

phenolics:-  they are characterised by the presence of the aromatic ring structure bearing one or more hydroxyl group . They are most abundant. They have distinctive absoraption characterstics.

Examples are the simple phenols, benzoquinones, phenolic acids, acetophenones, naphthoquinones, xanthones, flavonoids, isoflavonoids etc.

Functions:- they defense against ultravoilet radiations.

They give protection against herbivores and pathogens.

They help in attracting pollinator and fruit dispersor.

Tehy reduce the growth of nearby plants.

Alkaloids:- these are the nitrogen containing basic compounds found in the plants. They contains one or more nitrogen atoms usually in the heterocyclic ring and are heterogenous. Example are ephedrines, colchicine, erythromycin, pyrrole,pyridine, tropane, quinoline, indole etc.

Function:- they give protection against the herbivores. They also give antimicrobial defemse. They are bitter in taste so repels many animals.

Ans.109-110. The hierarchical order are which in which the different class are arranged in the specific order. The species which are having many similarities are placed in the lower class called as the species or subspecies. As we move upword, the similarities between species decreases. The correct order of the hierarchical order are as follow:-

Domain kingdom Phylum Class Family enus Species Subspecies Hierarchical Order