Biology Chapter:3
Short Question Answer
Q:1 Define and explain “Classification”?
Ans: Classification: Biologists mapped the whole diversity of organisms exist on earth, into simple
groups. To understand about the characteristics of specific organisms individually, is simply called
classification. Classification is actually based on the similar and dissimilar characteristics what
organisms shared with each other and by this biologist can easily study and identify the organisms.
Q.2: What is biodiversity?
Ans: Biodiversity: Biodiversity is the combination of two words; bio (life), diversity (variation) thus it
is defined as: "The biodiversity or biological diversity, is the degree of variation of either or among
the species even on different regions of the earth". It is comprised of different organisms such as
bacteria, protozoans, algae, fungi, animals and plants.
Q.3: Define taxonomy.
Ans: Taxonomy: Biologists classified the organisms in order to make them study easily, so the
science of classification is called taxonomy. (Tax = group, Nomy = naming)
Q.4: Explain the units of classification.
Ans: Units of Classification:
Species: Species is a group of organisms which can interbreed and produce fertile offspring.
Genus: Group of closely related species is called genus.
Family: Group of closely related genera is called family.
Order: Group of closely related families is called order.
Class: Group of closely related order is called class.
Phylum: Group of closely related classes is called phylum.
Kingdom: Group of closely related phyla is placed together in kingdom.
Q.5: What do you know about the structure of virus? Why virus is not placed in any kingdom?
Ans: Structure of Virus: Virus is non cellular obligate endoparasite (lives inside host cell) it does not
have cellular organization but do have nuclear material either DNA or RNA. It has protein coat called
capsid that encloses the nucleic acid. It reproduces only inside the host cell. It causes number of
diseases in plants like Tobacco Mosaic Disease etc. and animals like, cold, flue, dengue, polio,
hepatitis, AIDS etc. Due to its non-cellular nature, it cannot be placed in any of the five kingdoms.
Q.6: Define conservation of biodiversity.
Ans: Conservation of Biodiversity: Conservation of biodiversity simply is the way of caring, saving
the species, inhabit on earth from dangers.
Q.7: Write few lines on endangered and extinct species.
Ans: Endangered and Extinct Species: Due to human activities such as entertainment or food,
animals are becoming endangered (at risk of extinction in future) of some have gone extinct (surely
of not finding the last individual that species in ecosystem). Some of the endangered species are
mentioned below.
Q.8: Why scientific naming is necessary?
Ans: The advantages of scientific over common names are that they are accepted by speakers of all
languages, that each name applies only to one species, and that each species has only one name. As
common names cause many problems to identify the organisms as different regions have different
languages for the same thing for example; common name of onion (in Urdu) is "Piyaz" but in other
regions it is also known as 'Ganda' or 'basal' etc. but in scientific language it is known as Allium cepa.
Q.9: Why amoeba is not placed in animal kingdom?
Ans: We can't say amoeba or any other single celled heterotrophic organism as animal because they
don't come under the kingdom Animalia. They all comes under Kingdom Protista.
Q.10: How living organisms are classified into two kingdom classifications?
(See answer in form of flow chart on page number 35)
Q:11 Define and Draw chart on three kingdom classifications?
(See answer on page number 35 and 36)
Q:12 Explain the aims of classification.
Ans: Aims of Classification: The main aims of classification are:
(i) To determine similarities and dissimilarities among organisms so that they can be studied easily.
(ii) To find the evolutionary relationship among organisms.
Q:13 Define Conservation of biodiversity?
Ans: Conservation is the way of caring, saving the species, inhabit on earth from dangers.
Detailed Question Answer
Q:1 Briefly describe the history of classification.
Ans: History of Classification: The system that we still use today for giving scientific names to plants
and animals has many founders, from the Greek philosopher Aristotle to the Swedish physician and
botanist Carolus Linnaeus.
Aristotle: Taxonomy first began with the philosopher Aristotle (384-322 BC), sometimes called the
"Father of Science." It was Aristotle who first introduced the two key concepts of taxonomy as we
practice it today: classification of organisms by type and binomial designation. Aristotle was the first
to attempt to classify all the kinds of animals in his book on animals (Historia Animalium in Latin). He
grouped the types of creatures according to their similarities: animals with blood and animals
without blood, animals that live on water and animals that live on land.
Abu Usman Umer Aljahiz: Abu Usman Umer Aljahiz was the first eminent Arab zoologist of the
Muslim world. He used to slaughter animals for studying the internal organs of their bodies. He also
opened the abdomen of pregnant animals to find out the number of newborns and the position of
each one of them in the belly. His encyclopedic work in seven big volumes Kitab al-Haywan (Book of
Animals) is the most famous work on zoology, in which he has described diseases and treatment.
Carolus Linnaeus: He is considered as the father of taxonomy.
Q:2 Explain the Five Kingdom Classification?
(See answer on page number 37 to 39)
Q:3 Explain four kingdom Classification?
(See answer on page number 36)
Q:4 What do you know about binomial nomenclature? What are the advantages of scientific over
common names?
Ans: Binomial Nomenclature: A scientific name given to each species comprising two words is
known as binomial nomenclature.
Carolus Linnaeus, a Swedish naturalist and explorer, who was the first to frame principles for
defining natural species (plants and animals) and to coin a uniform system for naming them.
Through a system of nomenclature in which each species of animal, plant or other organism, has
been given two terms, in which the first identifies the genus to which it belongs and the second the
species itself or its specific names.
Advantages of Scientific Over Common Names: The advantages of scientific over common names
are that it is accepted by speakers of all languages, that each name applies only to one species, and
that each species has only one name. As common names cause a number of problems in identifying
the organisms as different regions have different languages for the same thing. For example, the
common name of onion in Urdu is "Piyaz" but in other regions it is also known as "Ganda" or "basal"
etc. but in scientific language it is known as Allium cepa.
This avoids the confusion that often arises from the use of several common names to designate
different things in different places or from existence of several common names for a single species.
Q:5 Describe the principles of binomial nomenclature.?
(See answer on page number 41)
Q:6 Explain the importance of biodiversity?
(See answer on page number 30)
Q:7 Write few lines on Endangered species and extinct species?
(See answer on page number 36)
Q:8 What is Deforestation? Describe its causes and effects on biodiversity?
(See answer on page number 45)
