Biological Classification (Intro)

Question 1

Classification was done..

Answer 1

instinctively not using criteria that were
scientific but borne out of a need to use organisms for our own use – for
food, shelter and clothing

Question 2

Who was the earliest to attempt a more
scientific basis for classification?

Answer 2

Aristotle

Question 3

Aristotle used (a) characters
to classify plants into (b)

Answer 3

(a) simple morphological
(b) trees, shrubs and herbs

Question 4

Aristotle divided animals
into two groups,

Answer 4

those which had red blood and those that did not.

Question 5

Linnaeus developed (a) classification

Answer 5

(a) Two Kingdom (Plants and Animals)

Question 6

L’s system did not distinguish between

Answer 6

(a) the eukaryotes and prokaryotes
(b) unicellular and multicellular organisms
(c) photosynthetic (green algae) and non-photosynthetic (fungi)
organisms

Question 7

Why was the two kingdom classification
used for a long time was found inadequate?

Answer 7

Classification of organisms into plants and animals was easily
done and was easy to understand, but, a large number of organisms
did not fall into either category.

Question 8

Besides, gross morphology
a need was also felt for including other characteristics like

Answer 8

(a) cell structure,
(b) nature of wall
(c) mode of nutrition,
(d) habitat
(e) methods of reproduction
(f) evolutionary relationships

Question 9

Classification systems for the living organisms

Answer 9

have undergone several changes over the time.

Question 10

Which kingdoms have been a constant under all
different systems?

Answer 10

Plant and Animal

Question 11

Though plant and animal kingdoms have been a constant under all
different systems,

Answer 11

The understanding of what groups/organisms be
included under these kingdoms have been changing.

Question 12

The (a) and
(b) of other kingdoms have also been understood differently by
different scientists over the time

Answer 12

(a) Number
(b) Nature

Question 13

The only chemosynthetic autotroph kingdom

Answer 13

Kingdom Monera

Question 14

The only holozoic heterotrophic kingdom

Answer 14

Kingdom Animalia

Question 15

Cell wall of Kingdom Monera is made up of

Answer 15

Non cellulosic (polysaccharides + amino acids)

Question 16

Who proposed a Five Kingdom Classification?

Answer 16

R.H. Whittaker (1969)

Question 17

Kingdoms in Five Kingdom Classification

Answer 17

Monera
Protista
Fungi
Plantae
Animalia

Question 18

The main criteria for classification used by Whittaker include

Answer 18

cell structure
body organisation
mode of nutrition
reproduction
phylogenetic relationships

Question 19

Six Kingdom Classification (or) Three Domain System

Answer 19

Divides the Kingdom
Monera into two domains, leaving the remaining eukaryotic kingdoms in the
third domain and thereby a six kingdom classification.

Question 20

What do the earlier classification systems include under Plants?

Answer 20

bacteria
blue green algae
fungi
mosses
ferns
gymnosperms
angiosperms

Question 21

The character that unified the plant kingdom was

Answer 21

that all the organisms included had a
cell wall in their cells.

Question 22

Drawback of the classification of plant kingdom based on presence of cell wall?

Answer 22

~ This placed together groups which widely differed in other characteristics.

Question 23

examples of drawbacks of plant kingdom?

Answer 23

~It brought together :
1) the prokaryotic bacteria and the
blue green algae (cyanobacteria) with other groups which were eukaryotic.
2) grouped together the unicellular organisms and the multicellular
ones (Chlamydomonas - unicellular and Spirogyra - multicellular) were placed under algae.

Question 24

The earliest classification did not differentiate between

Answer 24

the heterotrophic fungi and the autotrophic green plants though they also showed
a characteristic difference in their walls composition (fungi - chitin & plants - cellulose)

Question 25

All prokaryotic organisms were grouped together under

Answer 25

Kingdom Monera

Question 26

the unicellular eukaryotic organisms were placed in

Answer 26

Kingdom Protista

Question 27

Kingdom Protista has brought together

Answer 27

Chlamydomonas, Chlorella (earlier placed in Algae within Plants and both having cell walls) with Paramoecium and Amoeba (which were earlier placed in the animal kingdom which lack cell wall)

Question 28

Why did the new classification put together organisms which in earlier classifications were placed in different kingdoms?

Answer 28

This happened because the criteria for classification changed.

Question 29

Changes in the criteria will

Answer 29

take place in future too depending on the improvement in our understanding of characteristics and evolutionary relationships.

Question 30

Over time, an attempt has been made to evolve a classification system which reflects

Answer 30

not only morphological, physiological and reproductive similarities but also phylogenetic (evolutionary relationships)