BIOLOGY 9th Class , IBA Community College, AKUEB Pattern

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Chapter 3. Biodiversity
3.1 Introduction
3.1.1 define biodiversity;
Biodiversity is a measure of the variety of organisms present in different organisms present in different ecosystems.
3.1.2 Highlight the importance of biodiversity (producing food, obtaining drugs,
Getting industrial products, maintaining ecosystems; regulating resources and

Recycling

Food Production

Food has basic importance in our life. Due to researches in biology, there are great achievements in agriculture. For the production of cereal crops; the best varieties of seeds were selected. The yield of wheat corn, rice, sugarcane and cotton has been enormously increased bringing healthy effect and prosperity. Today, the man has overcome the problems of balanced diet, food storage and famine.

3.2 Aims and Principles of Classification
3.2.1 Describe the basis of classification of living organisms (with reference to
Homology, analogy, morphology, anatomy and embryology);

1.      Homology: It means those organs which are same in structure but different in their functions. For example, flipper of the whale, wings of a bat or an arm of man, internally are similar in structure and all are made up of muscles and bones but they are different in functions, flipper of whale is used for swimming, the wing of a bat for flight and the arm of man is used for grasping. In same way some organs are known as vestigial organs. Those organs of body which remain part of a body but are function less those organs are called as vestigeal organs.
2.      Analogy: classification of organisms on the basis of dissimilar characters.
3.      Morphology: Classification of organisms by observing their etrnel characters.
4.      Antomy: classification of organisms on the basis of their internel structure.
5.      Embryology: Classification of organisms by observing the genetic changes in them.


3.2.2 describe the aims and principles of classification;
These are given below:
1. To determine similarities and differences between different organisms.
2. To arrange organisms on the basis of similarities and differences.
3. To identify the organisms on the basis of their structure and other prominent characters and study them systematically and logically.
4. To find out inter-relationships of organisms.
First of all, Aristotle classified the organisms on the basis of their resemblances
The basic unit of classification is specie (Plural specie). A species is a group of organisms that can breed with one another in nature and produce fertile offspring. All members of a species have same number of chromosomes and also have many other features in common. All the mustard plants belong to one species. All the human beings belong to another species. The members of one species differ from members of other species and do not breed naturally with each other. Such different species, which are closely related, they are grouped in large group called genus (plural; genera) e.g. Brassica is a genus. It includes several species like mustard, cabbage and turnip. Similarly, Felis is a genus. It includes several species like lion, tiger and cat. Similarly, many closely related genera are placed in a bigger group called Family, families are grouped into an order, orders are grouped into a class and classes are grouped into a phylum (plural, phyla) or division (plural; division) in case of plants. The phyla or divisions are grouped into kingdom. All these units are divided into subunits e.g. sub genus, sub phylum and sub kingdom etc. The smallest the group or unit, the organisms found in this group, would be more similar, they have more number of of similar character.
3.3 History of Classification Systems
3.3.1 identify the contribution of Aristotle as the founder of biological classification;
The earliest known system of classification of organisms comes from the greek philosopher Aristotle. He first time classified the living organisms into two groups “plantae” or “animalia”.

3.3.2 explain the basis for establishing five kingdoms;
The basis for establishing five kingdoms were given by Robert whittaker.
1. The levels of cellular organization i.e. prokaryote, eukaryote and nui-cellular eukaryote.
2.The principal modes of nutition i.e. photosynthesis, absortion and ingestion.

3.3.3 compare Two-kingdom and Five-kingdom classification systems;
Two kingdoms
Five kingdoms
*All the organisms were classified in two kingdoms,plants or animals.

*Some organisms have both plant &animal like characters,so they were not able to be kept in two kingdoms.
*All organisms are classified in five different kingdoms.

*Organisms having different characters are classified in their own kingdom.

3.3.4 rationalise that Five-kingdom classification system better explains diversity of
living organisms;

3.3.5 state the contributions of Abu Usman Umer Aljahiz in unfolding the
characteristics of animal species;
He explained the characteristics of about 350 species of animals. He wrote on the life of aunts especially.
3.4 Units of Classification
3.4.1 define the units of classification (species, genus, family, order, class, division/phyla, kingdom);
·         Specie: group of natural population which can interbrees freely among themselves.
·         Genus: Closely related species are grouped in genus.
·         Family: Genera are grouped into families.
·         Order: Families are grouped into classes.
·         Class: Orders are grouped into classes.
·         Division;(Phylum: Group of related classes) Division for fungi or plants.
·         Kingdom: Phyla are grouped together into kingdoms.
3.5 The Five Kingdoms
3.5.1 describe the acellular structure of virus and justify why virus are excluded
from the Five Kingdom classification system;
1. Viruses are non-cellular parasitic entities (obligate parasite)
2. Viruses cannot live and reproduce outside the living cells because they lack the machinery to do so by themselves.
3. The size of the viruses in range 20nm-250nm.
4. Viruses are either virulent destroying the cell in which they occur. While temperate Viruses become integrated into their host genome and remain stable for long period of time.
These all characters differ them from others so they are excluded from the 5 kingdom classification system.
3.5.2 describe the salient features of prokaryotes taking bacteria as an example;
  •  Discovery of bacteria A.V.Leuventoek.
  • Size of bacteria = 0.2-2 micron (breadth)
  • = 2-10 micron (length).
  • Cell wall of bacteria made up of peptidoglycan.
  • Arch bacteria do not contain peptidoglycan.
  • Bacterial replications, cell division, respiration, export of enzymes = By means of mesosomes (invaginations of cell membrane)
  • Saprophytic bacteria form humus (important component of soil)
  • Photosynthetic bacteria = use H2S in photosynthesis instead of water.
  • Chlorobium chlorophyll or bacterial chlorophyll discovered by Von Nell 1930.


3.5.3 describe the salient features of protists taking chlamydomonas as an
example;
1. Chlamydomonas are microscopic, unicellular (as single cell performs all vital activities) organisms.
2. These organisms are asymmetrical.
3. The body of organism may be naked or covered by pellicle to maintain the shape.
4. Cytoplasm of chlamydomonas is usually divided into outer, ectoplasm and inner granular endoplasm.
5. Cell may be uninucleate or multinucleate. Nuclei are covered by nuclear membrane.
6. Chlamydomonas may be solitary or colonial.
7. They are aquatic and are found in both fresh and marine water.
8. Nutrition may be holozoic (animal like), halophytic (plant like) or saprozoic (subsisting in dead organic matter) or parasitic.
9. Digestion is intracellular and is accomplished inside the food vacuole.
10. Locomotion takes place by flagella, cilia or psendopodia.
11. Respiration takes place through general body surface.
12. One or more contractile vacuoles are present for osmo-regulation.
13. Reproduction takes place by both asexual and sexual methods.
14. The asexual methods include binary fission, multiple fission and budding.
15. Sexual reproductive methods include gamete formation (Isogamies and Anisogamous) or by conjugation.
3.5.4 Describe the salient features of fungi taking rhizopus as an example;
sThe body of rhizopus is composed of nonseptate hapjae, demonstrates the although there is little cellular differentitation amonf fungi, the hyphae may be specialized for various purposes. In rhizopus, stolens are horizontal hyphae that exist on the surface of bread ancher and the mycelium and carry out digestion: and sporangiophores are stacks that bear sporangia. A sporangia is a capsule that produces spores called sporagiospores.

3.5.5 describe the salient features of plants taking mosses, ferns and flowering
plants (monocot and dicot) as examples (salient features of each group
should be described only);
Mosses: The members of this group of tracheophyte plants are commonly called as “club moses” but they are not mosses, because mosses belongs to bryophytes, their cone is “club-shaped” so called as club mosses. They were found in middle of Devonian period, most 10 million years after the psilopsida. They formed the earth’s first forests. Some were few centimeter in height. Their leaves are small and scale like, resembling the leave like mosses. Now only five genera are alive today. Two of these are selaginella and lycopodium, these are commonly known as ground pine or running pine.  Lycopsids have true roots, leaves and stem. 
 Ferns : The members of this group of tracheophyte plants are mostly ferns. These ferns are the only seedless vascular plants that have broad leaves. They appeared in the Devonian period and become dominant carboniferous period. They posses true roots, stems and leaves. Ferns grow in cool, shady, moist places, both in the hills and in the plains. Leaves of ferns are usually pinnately compound. Stem is horizontal, flattened and web branched, growing along under the soil. Roots are adventitious. 
3.5.6 describe the salient features of invertebrates taking paramaecium, sycon,
jellyfish, tapeworm, roundworm, earthworm, snail, butterfly and sea star as
examples;
Phylum Porifera (GK: Porous = Pores + Ferro = form)
Main characters:
1. They are commonly called as sponges.
2. They are sessile animals.
3. Sponges range in height from about 1cm to 2cm.
4. More than 5000 species of sponges are found.
5. All are marine, while some are fresh water.
6. The central body cavity is called spongocoel.
7. A single large opening is called as osculum.
8. They are filter feeders.
9. Body lining is formed by flagellated cells called choanocytes or collar cells.
10. The are diploblastic and porous, pores called ostia.
Examples: Sycon, Leucosolenia, Spongilla.

Phylum Coelenterata: (GK. Koitos = Cavity + Enteron = Intestine)
Main Characters:
1. They are simple, multicellular and diplobastic but mesogloea is also found.
2. They are mostly marine.
3. More than 9000 living species are found.
4. They poses a central digestive cavity called as gastrovascular cavity or also called as gastrocoel.
5. A single opening is present which functions as both mouth and anus.
6. They are solitary or colonial.
7. They are also called cnidaria (GK. Cnide = nettle).
8. They are radial symmetrical.
9. Reproduction takes place by budding.
10. Circulatory, respiratory, excretory, and various other systems are absent.
Example: Hydra, Jelly-Fish, Sea-Anemone.

Phylum Nematoda (GK: Nema = Thread + helminthes = worm)
Main Characters:
1. They are commonly called as thread worms.
2. The aschelmenthes are also called as nematodes.
3. The nematodes are cylindrical, bilateral symmetrical and triploblastic animals.
4. They have tapered ends.
5. These round worms are found in most aquatic habitats, in wet soil, in the moist tissue of plant, and in the body fluids and tissues of animals.
7. Round worm range from less than 1mm to more than 1m in length.
8. Females generally being larger than males.
9. Usually the size of male ascaris is 15-20mm in length, while female is 20-50mm in length.
10. They have complete digestive system, with two openings mouth and an anus.
Examples: Ascaris, Hookworms, Thread worms, Guinea worms etc.


Phylum plathyhelminthes (GK: Platy = Flate + Helminthes = worm).
Main Characters:
1. They are commonly called as flat worms.
2. There body is dorso-ventrally flattened.
3. There are about 15,000 species of flat worms.
4. They are found in fresh water, marine water and damp terrestrial habitat.
5. They are free-living forms.
6. Some are parasites.
7. Parasites are ectoparasites or endoparasites.
8. They are microscopic to over 20m long.
9. They are bilateral symmetrical and acoelomic.
10. They are triploblastic.
11. Flame cells are the main excretory organs.
12. They are hermaphrodite.
13. A pair of ganglia are present.
Example: Planaria, Liver-flucke, Tape worm.

Phylum Annelida (L: Annellus = Ring)
Main Characters:
1. The annelids are commonly called as segmented worms.
2. They are long, cylindrical and bilateral symmetrical animals.
3. Body is metamerically segmented.
4. The body is covered with thin cuticle.
5. They are found in fresh-water, marine and terrestrial habitats.
6. A few species are also parasites.
7. A coelom is present.
8. Locomotion takes place by setae and parapodia.
9. The blood circulatory system consists of dorsal and ventral blood vessels.
10. Excretion takes place by nephridia.
Example: Earthworm, Neries, Leech etc.

Phylum Arthropoda (GK: Arthros = jointed + Podos = foot)
Main Characters:
1. They are commonly called as animals with jointed feet.
3. They are segmented and segmentation is externally.
4. The body is covered by chitinous exoskeleton.
5. The exoskeleton constructed from layers of protein and chitin.
6. They are bilaterally symmetrical and triplobastic.
7. They are fresh water, marine and terrestrial.
8. Body is divisible in to head, thorax and abdomen.
9. Head and thorax often fused to form cephalothorax.
10. Muscles are mostly striated.
Examples: Crab, Spider, Scorpion, Butterfly etc.

Phylum Echinodermata (GK: Echinos = hedgehot + derm = skin + ata = characterized)
Main Characters:
1. All are marine animals with 6000 species.
2. They are sessile or slow-moving animals.
3. Body is radial symmetrical.
4. Calcareous plates are present in the skin and most of them have dermal spines.
5. A coelom is present.
6. They are triploblastic.
7. The digestive system is complete.
8. Unique character is presence of water vascular system, which is network of hydraulic canal branching system.
9. Tube – feets are used for locomotion, feeding and gas exchange.
10. A nervous system consisting of an oral ring and radiating nerve cord.
Examples: Star Fish, Brittle Star, Sea-urchin etc.

1. Class: Gastropoda
Main Characters:
1. They are mostly marine but some are fresh water and terrestrial.
2. Body is asymmetrical.
3. Single spiral shell is present.
4. Foot is large and flat.
5. Head distinct with eyes, tentacles and mouth.
6. Carnivorous and filter-feeders.
7. Sexes are separate, some are hermaphrodite.
8. Fertilization is internal.
9. Oviparous or ovoviviparous. Examples: Slug, Pila, Snail etc.

Paramaecium:
 1.Unicelular organisms 2.free living founf in both fresh and sea water.
3.their haita is mostly moist soil, decying plants and animlas. 4. Feed in a variety of ways i.e. symbiosis etc. 5. Reproduce both sexually and asexually.


3.5.7 describe the salient features of vertebrates taking fish, frog, lizard, bird andcat as examples;

Characters of Class Pisces (fishes)

1. The class of fishes is called Pisces. They are aquatic vertebrates.
2. According to their size and shape, the fishes are of many kinds.
3. They have a head, a trunk and a tail.
4. The head and trunk are directly jointed together and neck absent.
5. Body of fish is flexible tapering at both ends and streamlined. This type of body helps in swimming.
6. They can swim with fins, which are attached to the trunk.
7. They body is covered with scales which remain moist by special type of secretion of body.
8. Breathing organs are gills which are present in the hollow spaces found on both sides of the head for exchange of gases i.e. oxygen and carbon dioxide.
9. Mouth has teeth, which is used for grasping instead of grinding of food.
10. In some fishes air pouch is present, which is called air bladder. The air bladder is used for buoyancy.

Class Amphibia(Frog)

1. This group of animals can live both in water and on land.
2. They need water for reproduction. Therefore they are called Amphibians.
3. The skin is thin, moist and slimy.
4. Small teeth are present in the upper jaw which is only used for grasping the prey.
5. Breathing organs are two lungs. Skin is also used for the exchange of gases.
6. Eggs are laid in water or moist places and their outer shells are not hard.
7. They are cold blooded animals e.g. they cannot maintain their body temperature constant.
8. They become very slow and bury themselves in the mud. This process is called hibernation.
9. During the process of reproduction fertilized egg is changed into adult passing through a number of physical changes. This process is called metamorphosis.
10. The fertilized egg develops into larva. The larva of frog is called Tadpole. It has tail and gills. This larva later changes into adult

Reptiles(lizardz)

1. Most of the reptiles are terrestrial and only a few five in water.
2. They are also called crawlers.
3. They have thick, dry and rough skin.
4. The skin is covered with scales which originate from the ectoderm.
5. There are present lungs for respiration.
6. Teeth are present in their buccal cavity, which are used for cutting and biting.
7. The locomotary organs are legs but snakes and a few types of lizards have no legs.
8. Most of the lizards are not poisonous except members of the genus Heloderma which are found in American desert.
9. All the reptiles lay their eggs on land. Water dwelling reptiles e.g. turtle also lay their eggs on land.
10. Their eggs have a tough outer shell of calcium carbonate.
Birds
1. Birds have a single unique feature, which makes them different from other animals which is the presence of feathers. Their forelimbs are modified to form wings while hind limbs help in walking, wading and sitting on the branches.
2. All the birds have horny beaks without teeth.
3. All the birds lay eggs.
4. All the birds must have two wings for support and propulsion, strong but light and hollow bones.
5. Their digestive system is able to digest high caloric food.
6. They have a higher blood pressure and higher metabolic rate.
7. Nervous system and especially eye sight is very well developed so that they can track their path even at a very high speed.
8. They migrate during winters towards warmer places covering thousands of miles.
9. It is the most studied and most observable class in the world.
10. The birds are very beautiful and have melodious voices

Mammals(cat)

Hair The body of mammals is covered with hair. In most of the mammals hair may cover the whole body but in a few may be restricted to some areas. The hair conserves heat of the body.

Glands Their skin is provided with sweet glands, scent glands, sebaccous glands and mammary glands.

Skeleton Two occipital condyles, secondary bony palate, three bones in middle ear and fused pelvic bones and seven cervical vertebrae are present in their skeleton.

External Ear Fleshy external ears are present in mammals.

Eyelids Moveable eyelids are present in mammals.

Teeth Two sets of teeth are present. Milk teeth are replaced by permanent set of teeth.

Brain Brain is higly developed. It perform more functions than that of other vertebrates.

Cranial Nerves Twelve pairs of cranial nerves are present.

Circulatory System Circulatory system has four chambered heart, persistent left aorta and non-nucleated biconcave red blood corpuscles are present in female.

Sexes Sexes are separate i.e. there are two individuals, male and female.

Fertilization Most of them have internal fertilization and fetus developed inside the uterus of female giving birth to their children.

Breast Feeding They feed the children by milk from mammary glands.

Endothermic They are endothermic i.e. they can maintain their body temperature according to the environment. It means that they are warm-blooded animals.


3.6 Binomial Nomenclature
3.6.1 describe the aims and principles of binomial nomenclature with examples;
The method of giving scientific names to organisms is called nomenclature. Same animal or same plants may be known by different names. It must have one scientific name so that there may be no confusion. To give such names to living organisms, the method was formulated by carolous Linnaeous (1753). This method is called Binomial Nomenclature. Because tis system is simple and comprehensive, so it is accepted and used in whole world.
Rules of Binomial Nomenclature
1. According to this method, every species of living organisms is given a Latinized scientific name consisting of two parts.
2. The first part is the name of genus and is called generic name. It starts with a capital letter.
3. The second part is the name of species and is called specific name. It starts with a small letter.
4. Both parts of scientific name of a species are either underlined separately or italicized.
The scientific name of mustard plant is Brassica campestris. The scientific name of rose plant is Rose indica. Similarly the scientific name of frog is Rana tigrina and that of human is Homo sapiens.
Significance of Binomial Nomenclature
Before establishment of binomial nomenclature, the names of organisms consisted of many words. These words were based on the characters of these plants or animals. In different countries, even in different parts of same country; local names were used for plants and animals. The same organism may be given different names e.g. turnip, shaljam, gongloo, thipar, and gogroon are all names of same plant. In England, there are at least fifty names for pansy. Similarly a single common name may be used for different kind of organisms e.g. the word “raspberry” is used for about 100 kinds of plants. This confusion can be avoided by giving each organism a scientific name according to binomial nomenclature proposed by Carolous Linnaeus in 1753. It is adopted by all taxonomists
Biological Classification of Man
Common Name —————– Man
Kingdom ——————— Animalia
Phylum ———————- Chordata
Class ———————– Mammalia
Order ———————– Primates
Family ———————- Hominidae
Genus ———————– Homo
Species ——————— Homo sapiens
Biological Classification of Frog
Common Name —————– Frog
Kingdom ——————— Animalia
Phylum ———————- Chordata
Class ———————– Amphibia
Order ———————– Salientia (Anura)
Family ———————- Ranidae
Species ——————— Rana tigrina

3.7 Conservation of Biodiversity
3.7.1 define conservation and highlight its importance;

3.7.2 identify the causes of deforestation and over-hunting;
Deforestation
Deforestation means cutting down of trees for the conservation of a forest to non-forest land. It is done for using the land for various purpose such as pasture, urban etc.
Over hunting
Over hunting is due to increase in the need of food of humans and to hunt animals for using in several industrial products for human.

3.7.3 Explain the impact of human activities such deforestation, over-hunting,
introduction or removal of a species and pollution on biodiversity;
Deforestation
Deforestation leads to species extinction and habitat loss. all species have specific food and habitat needs, tropical forest provide them the habitat but cutting down forests taking away the natural habitat of species. This has several impact on biodiversity of life as many species become extinct
Over-hunting
 Over hunting has been a significance cause of the extinction of hundreds of species and the endangerment of many more.
Introduction or removal of species
Introduction of non native species is an important and often overlooked cause of extinction. When new species are introduced in an ecosystem then the established species in an ecosystem may not survive.
Pollution
Pollution from chemical contaminants certainly posses a further threat to species and ecosystems.

3.7.4 explore some plant and animal species which have become endangered or are
extinct due to human interference
Indus dolphin: the indus dolphin is a fresh water mammal. According to WWW-P, only  600 animals of this species are left in the indus and are close to extinct. The cause for this is water pollution, poaching, deforestation of habitat due to barrages and dams etc

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