1st year biology Chapter 5 Variety of life Question an Answers

Short and Simple Question an Answer

Q1: What is the basic unit of classification?

Ans: Species is the basic unit of classification.

Q2: Previously organisms were divided in how many kingdoms?

Ans: Previously organisms were divided in to two kingdoms. The plant kingdom and The animal kingdom.
Q3: Define species?

Ans: Species is the group of organisms which are capable of interbreeding and are producing fertile offspring.

Q4: What is capsid?
Ans: Protein coat that encloses the viral genome is called capsid.

Q5: Name the different parts of viruses?
Ans: Viral genome, capsid, envelops, and tail fiber.

Q6: What modifications were proposed by Margulis and Schwarts in Whittaker’s scheme?
Ans: They suggested that multicellular algae should be removed from plant kingdom and placed along with all unicellular organisms in a new kingdom called the protoctist which would replace Whittaker’s protist kingdom.

Q7: What was the major snag in Whittaker’s scheme?

Ans: The major snag of his scheme was placing of unicellular algae in protist and multicellular algae in plant kingdom.

Q8: What are two criteria used by Whittaker in his scheme of classification?
And: He based his classification on two main criteria
1)Level of organization and 2) Methods of nutrition.

Q9: What are virods?
Ans: These are pathogens without capsid consists of tiny molecules of naked RNA and they infect only plants.

Q10: Define bacteriophage?
Ans: Viruses that infect bacteria bacteriophage. are called

Q11: What diseases are caused by Rhinoviruses?
Ans: Rhinoviruses caused the diseases of nose and throat.

Q12: What is meant by taxon?
Ans: Grouping of organisms within the hierarchy is called taxon and each taxon has a rank and a name.

Q13: binomial nomenclature?
Ans: Linnaceus’s system of giving each species a scientific name comprising of two words is known as binomial nomenclature.

Q14: Define kingdom monera?
Ans: It is the kingdom of prokaryotes which take their food by different methods.

Q15: On what basis previously organisms were divided into two kingdoms?
Ans: Previously organisms were divided into two kingdoms on the basis of presence or absence of cell wall.

Q16: Which virus causes the AIDS?
Ans: AIDS is caused by Human Immuno deficiency Virus (HIV) a retrovirus.

Q17: What are two major routs by which a plant viral diseases can spread?
Ans: A plant viral disease can spread by horizontal transmission or vertical transmission.

Q18: Why bacteria and fungi previously placed to the plant kingdom?
Ans: Previously bacteria and fungi placed to the plant kingdom because they were like plants and possessed a cell wall.

Q19: Why protoctista considered a something of ‘Rag- bag’?
Ans: Protoctista considered as something of Rag- bag because it contains all multicellular and unicellular organisms which can not be fitted to any of the other kingdom.

Q20: Why scientists suggested that multicellular algae should be removed from plant kingdom?
Ans: They suggested that multicellular algae should be removed from plant kingdom because multicellular algae is more close to unicellular algae than plants and this is why they placed in new kingdom called protoctista.

Q21: How fungi are different from green plants?

Ans: Fungi lack chlorophyll, they feed heterotrophically through absorption and their cellular structures are also different from plants.

Q22: Why viruses are not included in five kingdoms?
Ans: Viruses are not included in five kingdoms because they are on the borderline between the living and nonliving due to its noncellular nature, presence of only nucleic acid surrounded by protein coat and it is parasite.

Q23: Why Tobacco Mosaic disease is called as Mosaic disease?
Ans: Because it causes the leaves to wrinkle and become mottled and mottled effect has the appearance of Mosaic.

Q24: Why virus which attacks on bacteria is known as bacteriophage virus?
Ans: They are so called because they attack bacteria. and destroy it.

Q25: Why a virus that reproduces only by lytic cycle is known as virulent?
Ans: A virus that reproduces only by lytic cycle is known as virulent because it causes death of bacterial cell.

Q26: How viruses are classified?
And: Viruses are classified on the basis of morphology and nucleic acid they contain.

Q27: Why lysogenic phase of virus is known as temperate phase?
Ans: Because it replicates the viral genome without destroying it.

Q28: Why some viruses are referred as arboviruses?
Ans: Some viruses are referred as arboviruses because they are transmitted by insects and other arthropods.

Q29: How chemical constitution can be helpful in the classification of living organisms?
Ans: When morphological characters are failed to classify living organisms because of their similar cellular structures then their chemical constituents are used to classify and identify them.

Q30: Why bacteriophage is known as tadpole virus?
Ans: Bacteriophage is known as tadpole because of its tadpole shape with its head and tail regions.

Q31: Why viruses are harmful for other living organisms?
Ans: Viruses are harmful for other living organisms because they cause many widespread diseases in living organisms.

Q32: How living organisms are classified?
Ans: Living organisms are classified on the basis of homology, comparative biochemistry, cytology and genetics.

Q33: How plus strand RNA viruses are different from minus strand RNA viruses?
Ans: Plus strand RNA act directly as mRNA after infecting the host cell, attacking to the host’s ribosomes and being transmitted where minus strand RNA carry the RNA strand complementary to the mRNA that carries the genetic information of the mRNA, which then function in the cell.