9th Class Chapter 3 Biology Long Questions

What is Classification?Describe the aims and basics of classifications.

Ans. Definition The arrangement of organisms into groups and subgroups on the basis of similarities and differences is called classification. Known Number of animals and plant species: Over 1.5 million types of animals and over 0.5 million types of plants are known to biologists. Size They range in complexity from small and simple bacteria to large and complex human beings. Habitat Some of the organisms live in sea, some on land, some walk, others fly and still others are stationary. Need of classification: Each species has its own way of life. When there are so many kinds of organisms, biologists classify the organisms to study such a large collection in an easy way. Taxonomy The branch of biology which deals with scientific naming and classification of organisms is called taxonomy. Systematics The branch which deals with classification and also traces the evolutionary history of organisms is known as systematics. Aims of Classification: The main aims of classification are: (i) To determine similarities and differences among organisms so that they can be studied easily. (ii) To find the evolutionary relationships among organisms. Basis of Classification: Classification is based on relationship among organisms and such relationship is got through similarities in the form or structure. These similarities are seen in:- 1. Structures (both external and internal) 2. Biochemistry 3. Modern Genetics These similarities suggest that all organisms are related to one another at some point in their evolutionary histories. However, some organisms are more closely related than others. For example; sparrows are more closely related to pigeons than to insects. It means sparrows and pigeons have common evolutionary histories.

What is taxonomic hierarchy?

Ans. Taxa The groups into which organism are classified are known as taxonomic categories or taxa. Taxonomic Hierarchy The taxa form a ladder called taxonomic hierarchy. All the organisms are divided into five kingdoms. So kingdom is the largest taxon. On the basis of similarities, each kingdom is further divided into smaller taxa in the following way: Phylum: A phylum is a group of related classes. Class: A class is a group of related orders. Order: An order is a group of related families. Family: A family is a group of related genera. Genus: A genus is a group of related species. Species: A species consists of similar organisms. Table 3.1 Simple classification of two organisms Taxa Human Pea Kingdom Animalia Plantae Phylum / Division Chordata Magnoliophyta Class Mammalia Magnoliopsida Order Primates Fabales Family Hominidae Fabaceae Genus Homo Pisum Species H. sapiens P. sativum

Define Species.Give two expectations for the species concept.

Describe the two Kingdom system of classification.

Ans. It is the oldest system and classifies all organisms into two Kingdoms i.e., Plantae and Animalia. Plantae: All organisms that can prepare food from simple inorganic materials and thus can store energy are autotrophs. According to this system bacteria, fungi and algae were included in kingdom plantae. Animalia: The organisms that cannot synthesize their food and depend on autotrophs or others are heterotrophs and are included in kingdom Animalia. Objection/Drawbacks++ (i) Some taxonomists found this system unworkable because many unicellular organisms like Euglena have both plant-like (Presence of Chlorophyll) and animal-like (Heterotrophic mode of nutrition in darkness and lack cell wall) characters. So, there should be a separate kingdom for such organisms. (ii) This system also ignores the difference between organisms having prokaryotic and those having eukaryotic cells.

Describe the three Kingdom Classification System.

Ans. In 1866, Ernst Hackle solved the first objection and proposed a third kingdom, Protista, for the placement of Euglena like organisms. He included a kingdom Protista. In this system, fungi were still in the kingdom Plantae Objection/Drawback (i) This system did not clear the difference between prokaryotes and eukaryotes. (ii) Some biologists disagreed about the position of fungi in kingdom Plantae. Fungi resemble plants in many ways but are not autotrophs. They are special form of heterotrophs that get their food by absorption. They do not have cellulose in their cell walls rather possess chitin.

Describe the five kingdom system of classification.

What is meant by binomial nomenclature? Describe its rules and significance.

Ans. Introduction of binomial nomenclature. It was introduced by Swedish biologist Carolus Linnaeus (1707-1778). His system spread rapidly. It became popular. Many of his names are in use today. Definition: Binomial nomenclature is the method of giving scientific names to living Organisms. Explanation: The scientific names of a species consist of two names. Genus: The first is the genus name. Species: The second one is the name of the species. Rules of Binomial Nomenclature:- (i) Scientific names are usually printed in italics, such as Homo sapiens. When handwritten, they should be underlined as Homo sapiens. (ii) The first term (generic name) always begins with capital letter while the species name is never capitalized (even when derived from a proper name). (iii)The scientific name should generally be written in full when it is first used but when several species from the same genus are being listed, it may then be abbreviated by just using an initial for genus. For example, Escherichia coli becomes E. coli. Significance of binomial nomenclature Problems caused by common names Common names cause many problems. (i) Many names for the same organisms Various regions have different names for the same organisms e.g. the common name of Onion in Urdu is Piyaz, but in different regions of Pakistan it is also known as Ganda, Bassal or Vassal. In other countries, it has other sets of names. In science, it is known with a single name as Allium cepa. (ii) Same names for many organisms In some cases, several organisms are called by the same common name: For example; `Black bird is used for crow as well as for raven. (iii)Common name without scientific basis Common names have no scientific basis. E.g. a fish is vertebrate animal. It has fins and gills. But there are several common names like 'silverfish', 'crayfish', `Jellyfish' and 'Starfish'. They do not fit the biologist's definition of a fish. Advantages (i) To avoid all these confusions, organisms are given scientific names by using binomial nomenclature. (ii) This system has great value and stability of its names. It has widespread use. (iii) Every species can be unambiguously identified by binomial nomenclature. It requires just two words. (iv)The same name can be used all over the world, in all languages. It avoids the difficulties of translation. e.g. Examples: Common Name Scientific Names Onion Allium cepa Common sea star (starfish) Asterias Rubens House crow Corves spenders

Descrtibe the converstion of biodiversity,Aslo write dwon impact of human being on biodiversity.

Write a note on Endangered Species in Pakistan.

<gwmw class="ginger-module-highlighter-mistake-anim ginger-module-highlighter-mistake-type-1" id="gwmw-15864117877487572977984">Qno</gwmw> 5 a What is meant by binomial nomenclature? Describe its rules and significance.

Binomial Nomenclature :

Write the impact of human beings on Biodiversity.

1000 years ago these were about 5 million people on earth with the advancement in agriculture and industry. Human population began to grow rapidly Today around 600 million people live on it. To improve the living condition for 600 million human. We are imposing threats to the survival of biodiversity Habitat loss. deforestationover-hunting introductionor removal speies

Describe the characteristics of <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15864125132467878389029">kingdom Monera</gwmw> with <gwmw class="ginger-module-highlighter-mistake-type-3" id="gwmw-15864125132461756408690">example</gwmw>.

Kingdom Monera:

What is meantby taxonomy/? Write taxonomic Hierarchy in order

The group into which organisms are classified are known as taxonomicscategories or taxafrom a ladder called taxanomichierarchy organisms are divided into five kingdom So kingdom is the longest taxonon the basis of similarities each kingdom is further divided into smaller taxain the following way

Write a note of kingdom <gwmw class="ginger-module-highlighter-mistake-type-1" id="gwmw-15864134300645463333440">protista</gwmw> and kingdomPlantae.

Kingdom protista:

What is conservation of biodiversity ? Why it is necessary ? What are the strategies in Pakistan for conservation of biodiversity ?

Conservation of biodiversity : Through rich in biodiversity , Pakistan today faces severe threats to its animal and plant species . The greatest concern is the loss of natural habitats . Main causes of this loss are rapid growth in human population and the prevailing poverty in rural areas of Pakistan . In addition low literacy rate is also a reason for the failure of conservation measures takes so far . The international union for the Conservation of nature and natural resources (IUCN) and world wildlife Fund-Pakistan work in close coordination with Pakistan's ministry of environment and other government and non government institutions . The IUCN has prepared for the first national red list (list of endangered or threatened species)

Write a note endangered species in Pakistan

Endangered species in Pakistan :