Case study (4 Marks)

Question 14 Marks

Can you identify the correct sequence of taxonomical categories?

Species → Order → Phylum → Kingdom
Genus → Species → Order → Kingdom
Species → Genus → Order → Phylum

Answer

He correct hierarchical arrangement of taxonomic categories in ascending order is Species → Genus → Family → Order → Class → Phylum → Kingdom Therefore, both (a) and (c) represent correct sequences of taxonomic categories. In sequence (b), species should be followed by genus. Therefore, it does not represent the correct sequence.

View full question & answer→

Question 24 Marks

Try to collect all the currently accepted meanings for the word ‘species’. Discuss with your teacher the meaning of species in case of higher plants and animals on one hand, and bacteria on the other hand.

Answer

Species occupies a key position in classification. It is the lowest taxonomic category. It is a natural population of individuals or group of populations which resemble one another in all essential morphological and reproductive characters so that they are able to interbreed freely and produce fertile offsprings. Each species is also called genetically distinct and reproductively isolated natural population. May (1964) has defined species as “a group of actually or potentially interbreeding populations that are reproductively isolated from other such groups”. In higher plants and animals the term ‘species’ refers to a group of individuals that are able to interbreed freely and produce fertile offsprings. But, in case of bacteria interbreeding cannot serve as the best criteria for delimiting species because bacteria usually reproduce asexually. Conjugation, transformation and transduction, which are termed as sexual reproduction methods in bacteria, also do not correspond to true interbreeding. Thus, for bacteria many other characters such as molecular homology, biochemical, physiological, ecological and morphological characters are taken into consideration while classifying them.

View full question & answer→

Question 34 Marks

Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal.

Answer

The arrangement of various taxa in a hierarchical order is called taxonomic hierarchy. The hierarchy indicates the various levels of kinship. The number of similar characters of categories decreases from lowest rank to highest rank. The hierarchical system of classification was introduced by Linnaeus. The hierarchy of major categories is: Species → Genus → Family → Order → Class Kingdom - 4 — Phylum or Division Increasing specificity → Decreasing specificity Classification of a plant (Wheat):

Kingdom – Plantae

Division – Angiospermae

Class – Monocotyledonae

Order – Poales

Family – Poaceae

Genus – Triticum

Species – aestivum

Classification of an animal (Housefly):

Kingdom – Animalia

Phylum – Chordata

Class – Insecta

Order – Diptera

Family – Muscidae

Genus – Musca

Species – domestica

View full question & answer→

Question 44 Marks

The process to standardize the naming of living organisms is called nomenclature. Obviously, the nomenclature is only possible when the organism is described correctly and we know to what organism the name is attached to this is identification. The system of providing scientific name with two components is called Binomial Nomenclature. The scientific name ensures that each organism is identified by only one name all across the world. They also ensures that such a name has not been used for any other known organism. Scientific names for plants are provided in ICBN and for animals, in ICZN.

(1). Who proposed binomial nomenclature?
(A) Carolus Linnaeus (B) Charles Darwin (C) Francis crick (D) Albert Einstein

(2)Which of the following is an example of binomial scientific name?
(A) Green algae (B) Rana tigrina (C) Snow leopard (D) China rose

(3). In binomial nomenclature, the name of organism consists of
(A) kingdom (B) genus (C) species (D) Both B and C

(4). ICBN stands for
(A) Internal botanical congress names
(B) International center of botanical names
(C) International code of botanical nomenclature
(D) Internal code of botanical nomenclature

(5). In binomial nomenclature,------- epithet starts with small letter
(A) Genus
(B) Species
(C) Both A and B
(D) None of the above

Answer

(1 - A), (2 - B), (3 - D), (4 - C), (5 - B)

View full question & answer→

BIOLOGY Case study (4 Marks)

Take a timed test