KERALA PSC / BIOLOGY / KINGDOM CLASSIFICATION / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

 

KERALA PSC / BIOLOGY / KINGDOM CLASSIFICATION / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / BIOLOGY / KINGDOM CLASSIFICATION / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

·      Five kingdom classification was developed by R.H Whittaker

·      The five kingdoms are Monera, Protista, Fungi, Plants and Animals

 

KINGDOM MONERA

·      Kingdom Monera are organism with prokaryotic cells and divers nutritional habits including photosynthesis, chemosynthesis and absorption. Reproduction is asexual by simple cell division for blue green algae.

·      Antibiotic drugs like streptomycin, erythromycin etc are obtained from actinomycetes.

 

KINGDOM PROTISTA

·      Kingdom Protista are colonial eukaryotes with diverse nutritional habits, reproduce both sexual and asexual involving meiosis and nuclear fusion. Mobility is by means of more advanced type of flagella. Eg: Dinoflagellates, yellow-green algae etc…

 

KINGDOM FUNGI

·      Kingdom Fungi are multinucleate organisms with non – photosynthetic nutrition through absorption, lacking tissue differentiation. Eg: Slime molds, bread molds etc…

·      Multi nucleate, non – photosynthetic, non – motile organisms. Reproduction is by both asexual and sexual means.

·      Two divisions – myxomycophyta (slime molds) and Eumycophyta (True fungi)

·      The true fungi is characterized by a definite cellular body composed of filaments called mycelium. The individual mycelium filaments is called hyphae.

·      Water molds, bread molds, club fungi are examples

·      Ascospores or basidiospores are the products of sexual reproduction in Fungi.

 

THE PLANT KINGDOM

·      Plants are the primary producers in nature

·      Flora is the plants of a particular region and Fauna is the animals of a particular region. Flora and Fauna together constitute the plants and animals of a region.

·      The part of the earth and its atmosphere that is capable of supporting living things is the biosphere.

·      Biosphere is divided into Lithosphere, Hydrosphere, Atmosphere etc…

·      Nitrogen Fixation means conversion of atmospheric nitrogen into useful compounds like nitrates with the help of bacteria and fungi

·      The biological nitrogen fixation is done by nitrogen fixing bacteria such as Rhizobium, Nostoc and Azetobactor.

·      Plants absorb the element nitrogen in the form of nitrates

·      Cyanobacteria is a blue green algae

·      The profuse amount of pollen grains liberated by pine forests at the time of pollination during the months of March-April is referred to as ‘Sulphur Showers’

·      Araucaria embricate, a gymnosperm plant is commonly known as ‘Monkey’s Puzzle’.

·      Litmus is obtained from a lichen

·      Lichen is an association of fungus and algae

·      Turmeric is obtained from the stem of plant

·      Cloves are dried flower buds of plant Syzygium aromaticum

·      Potato is a tuber crop

·      The native place of potato is America

·      Vanilla, a flavouring material, is extracted from the fruit of an orchid ‘Vanilla planlifolia’.

·      Rubber is obtained from the latex of Hevea brasiliensis

·      The milky juice that oozes from some trees like rubber is known as latex

·      Cotton, jute, silk, wool etc… are natural fibres and nylon is artificial fibre

·      Sugarcane is a type of grass

·      The fruit sugar is fructose

·      Tissue culture is the method of producing plants from minute plant fragments

·      The wall of the plant cell is made of cellulose. The cellulose cannot be digested by human alimentary canal.

·      The largest flower in the world is Rafflesia and the smallest one is Wolffia (duck weed)

·      The largest sperms among plants are found in gymnosperms

·      In plants gaseous exchange occur through stomata

·      The roots which do not grow from a main root (radicle) but directly from the stem are called adventitious roots

·      DNA (Deoxyribo Nucleic Acid) and RNA (Ribo Nucleic Acid) are the two kinds of nucleic acids.

·      In a plant cell, DNA is found in chloroplast, mitochondria and nucleus

·      Nepenthes, sundew, drosera etc… are some of the insectivorous plants.

·      Venus – fly trap (Dionaea muscipula): Venus fly trap which is found in America. Its leaves have beautiful red coloured elevations on both sides. Whenever an insect sit on a leaf it closes like a fork and the plant digests the trapped insect by digestive juices.

·      Insectivorous plants obtain nitrogen from animal bodies

·      Utricularia: It is a water plant. It is found all over the world. The roots of this plant which are submerged in water have bulbous bladders. When some aquatic insect enters the bladder, the hair on its opening do not allow it to come out. The walls of these bladders gives out a digestive juice, which suck the proteins out of the bodies of these small insects.

·      Organisms which obtain their food from non-living material in their environment are called saprophytes.  

 

CLASSIFICATION OF PLANT KINGDOM

·      Rhodophyta (Red algae): Are mostly multicellular marine plants. Their reddish colour is due to a pigment, phycoery thrin.

·      Phaeophyta (Brown algae): Are multicellular marine plants growing on rocks or attached to sea shores. Their brownish colour is due to xanthophyll pigment called fucoxanthin.

·      Chlorophyta (Green algae): Are a group of bright green aquatic, unicellular plants

·      Bryophyta: Simple, non-vascular small plants grow in moist places. Thallus like plant body is attached to the soil by rhizoids

·      Lycopodophyta (club mosses): Multicellular terrestrial plants with vascular tissues.

·      Arthrophyta (Horsetails): Are multicellular plants with vascular tissues. Arthrophyta are largely an extinct group represented by a single living genus, the Equisetum.

·      Pterophyta (Ferns): Are multicellular plants with vascular tissues; Here seeds are not produced.

·      Cycadophyta: Are multicellular terrestrial plants with vascular tissues. The stem is large and woody, leaves are large and fern like. Eg: cycas, zamia (sago tree), etc..

·      Conifers (Coniferophyta): Are multicellular plants with well-developed tissues. Leaves are simple, smaller than the cycadophyta and needle like. Eg: Cedrus (deodar), Taxus (Yew), Pine.

·      Angiosperms (Anthrophyta): More advanced flowering plants with well-developed vascular tissues. They make up more than half of all known species of plants.

·      They range is size from minute – floating duck weeds to giant eucalyptus and silk – cotton trees, and include plants of a great variety of forms – cacti, water lilies, sunflowers, orchids, pitcher plants, Indian pipe etc… The reproductory organ of these plants are flowers, and the seeds are enclosed within an ovary which develops into a fruit-wall. The distinct parts of the body of these plants are:

Ø Root: It anchors the plant to the soil and absorbs water and minerals and salts from the soil

Ø Stem: It bears nodes and internodes and supports leaves, flowers and fruits

Ø Leaves: are generally green and carry out the function of synthesis of food (photosynthesis)

Ø Flower: is the reproductive organ of angiosperms. It generally consists of four whorls: sepals, petals, stamens and pistils. After pollination and fertilization of the ovary of the pistil develops into fruit and the ovules into seeds. Some flowers are found in group or a clusters which are called peduncle. The arrangement of flowers on the peduncle is called inflorescence. The ripened ovary becomes a fruit which generally contains seeds.

·      On the basis of morphology, angiosperms are further classified into (i) herbs (ii) shrubs and (iii) trees.

·      On the basis of age, they are grouped as

Ø Perennials: which live for many years

Ø Annuals: which produce flowers and fruit in the course of a single season

Ø Biennials: which live for two seasons

·      Flowering plants are divided into two classes: Dicotyledons (Dicots), Monocotyledons (monocots)

Ø Dicotyledons: These plants have two cotyledons in their seeds and may be annuals, biennials or perennials. Eg: Hard wood trees, pulses, most fruits and vegetables many spices, beverages crops and many ornamental crops.

Ø Monocotyldons: These are mostly annuals and have only one cotyledon in their seeds. Eg: Cereals, Bamboo, Sugarcane, banana, palms, lilies, orchid.

 

OTHER CLASSIFICATIONS

·      Terrestrial: Plants which grow in soil

·      Hydrophytes: grow in water

·      Epiphytes: which perch on other plants but do not take nourishment from them.

·      Xerophytes: Are adapted to grow in a dry habitat like desert and can survive without moisture. Eg: cactus

·      Mesophytes: Thrive under condition intermediate between very wet and very dry. The great variety of crops such as beans, tomatoes, pear etc… belong to this category.

·      Parasitic: which depend on other plants for their nourishment. They lack chlorophyll and thus cannot make their own food. Eg: bacteria, fungi

·      Carnivorous plants: plants which trap insects and other small creatures on their sticky leaves

·      Modification of plants: sometimes certain parts of a plant are modified to carry out specific function.

 

ROOT MODIFICATIONS

·      Storage Roots: store food material, for eg: carrot, raddish, turnip, sweet potato

·      Aerial Roots: are aerial nodes that develop from the stem and go into the soil. For example: stilt roots of sugarcane and maize

·      Parasitic roots: arise from stem and penetrate into the host plant. They are called Haustoria. For eg: Cuscuta

·      Respiratory Roots: have pores and are founding plants that thrive in swamps. For eg: Rhizopora

·      Assimilatory Roots: contain chlorophyll and perform the function of carbon assimilation. For example: Trap roots

·      Epiphytic Roots: are aerial roots which absorb moisture from air, for eg: vanda roots

·      Stem modification: In some plants the stem is modified to perform different functions. They are:

Ø Rhizomes: Underground modification of the stem. They bear nodes and store food material for example: ginger, grass and canna

Ø Tuber: are swollen tips of underground branches that store food, for example: potato

Ø Corm: underground stem which bears leaves, for example: saffron, gladiolus

Ø Bulb: is a modified underground stem in the form of a disc – like structure that bears fleshy leaves that store food material, eg: onion, lilies

Ø Cladophyll: is a modification of the stem into a large, flat green and fleshy, structure that bears leaves into spines. Such stems carry out the function of leaves. For example: cactus

Ø Tendril: an aerial modification of the stem where the stem where the stem becomes a long, slender, coiling structure serving as an organ of attachment for certain climbing plants. It helps the plant to climb up the support, such as grapes and cucurbits.

KERALA PSC / BIOLOGY / KINGDOM CLASSIFICATION / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY