1 – Living world and classification of Microbes
Q 1. State whether the following statements are True or False.
Explain your statement :
(1) Lactobacilli are harmful bacteria.
Ans.
False.
Explanation
: Lactobacilli are useful bacteria. They are used for curdling the milk. They are
also used for preparing variety of milk products.
(2)
Cell wall of fungi is made up of chitin.
Ans. True.
Explanation
: The cell wall of the plants is made up of cellulose while the cell wall of
fungi is made up of complex sugar called chitin. Inside the fungal cell wall
there is cytoplasm which contains many nuclei.
(3)
Organ of locomotion in amoeba is pseudopodia.
Ans.
True.
Explanation
: Amoeba is a protozoan, primitive organism which possesses pseudopodia as the
organ for locomotion.
(4) Tomato wilt is a viral disease. Ans. True.
Explanation : Tomato wilt is a viral disease. These
viruses are able to infect only plant cells.
Q. 2
Find out my partner:
Ans.
(1) Fungi - Candida (2) Protozoa - Amoeba (3) Virus - Bacteriophage (4) Algae -
Chlorella (5) Bacteria - Prokaryotic.
Q. 3
Who am I?
(1)
I don't have true nucleus, cell organelles or plasma membrane.
Ans.
Microbe from Monera
(2)
I have nucleus and membrane bound cell organelles.
Ans.
Protozoan from Protista/I am any one of Eukaryote
(3)
I live on decaying organic matter.
Ans. Fungus
(4)
I reproduce mainly by *cell division. (* Binary fission)
Ans.
Bacteria and some Protozoa.
(5) I can produce my replica.
Ans.
Virus
(6) I am green , but don’t have
organs.
Ans.
Algea
Q. 4
Arrange the following in ascending order of size :
Bacteria,
Fungi, Virus, Algae.
Ans.
Virus, Bacteria, Fungi. Algae.
Q. 5
Give answers :
(1) State
the merits of Whittaker's method of classification.
Ans. I. Merits of Whittaker's classification :
(1) The classification system that Whittaker has adapted is
totally based on scientific foundation.
(2) Prokaryotes are placed separately in a different
kingdom. The prokaryotic organisms are different from other organisms, thus
placing them separately is justified.
(3) All unicellular eukaryotic organisms are clubbed
together in one kingdom named, Protista. This has helped to solve the placement
of Euglena.
(4) Euglena has chloroplasts like plants but as animals it
has flagella and thus there was conflict about such species during previous
classification systems. It was placed in protozoa previously.
(5) Fungi are saprophytic and hence they are placed
separately in a unique kingdom
(6) According to five kingdom classification, the cell
structure, organization of cell, mode of nutrition,
lifestyle and phylogenetic relationship are taken into
consideration.
(7) Therefore the system of 5 kingdom classification becomes
most authentic system of biological classification.
(2)
Write the characteristics of viruses.
Ans.
(1) Viruses are extremely minute of the size range of 10 nm to 100 nm. They are
on the border line of living and non-living. They are 10 to 100 times smaller
than bacteria and are visible only through the electron If microscope.
(2)
Though they are not considered as living, they can make replica of their own.
(3)
They exist in the form of independent particles. They are long molecules of DNA
or RNA which are covered by a protein coat.
(4)
Their survival is possible only inside the living plant or animal celles. When
they infect the host cells, they produce their own proteins with the machinery
of the host cell. These proteins from many replices of the infecting virus.
(5) This infection destroys the host cell and the virus
replicas are released. These free replicas re-infect the other adjoining cells
of the host
(6) Most of the viruses are pathogenic, they cause diseases
in plants and animals.
(3)
Which living organisms are included in the kingdom Monera?
Ans.
(1) All the living organisms belonging to Kingdom Monera are unicellular.
(2)
The mode of nutrition in them is either autotrophic or heterotrophic,
(3)
All of them are prokaryotic and thus they do not have well-formed nucleus. The
nuclear membrane and the cell organelles are absent in them.
(4) Kingdom Monera consists of different types of
bacteria and blue-green algae. E.g. Bacteria Clostridium titani, Vibrio
choleri. Treponema pallidum, Streptococcus pneumoniae, Legionella pneumoniae,
Salmonella typhi, Staphylococcus aureus, Clostridium botulinum.
(4) Explain the nutrition in fungi.
Ans.
Most of the fungi are saprophytic in their nutrition. They absorb the nourishment
from dead and decaying matter. By taking the organic matter from dead bodies of
plants and animals, fungi survive. In this process they degrade the organic
matter
completely.
Q 6.
Use Whittaker method to classify bacteria, protozoa, fungi, algae, prokaryotic,
eukaryotic, microbes.
Ans.
Bacteria : Kingdom Monera
Protozoa
: Kingdom Protista
Fungi
: Kingdom Fungi
Algae
: If unicellular, Kingdom Protista. If multicellular, Kingdom Plantae
Prokaryotic
: Kingdom Monera
Eukaryotic
: Any kingdom other than Monera.
Microbes : Kingdom Monera or Protista.
Q 7. Complete the chart:
Complete the five kingdom method of classification using -
living organ karyotes, eukaryotes, multicellular, unicellular, protista,
animals, plants, fungi.
Q 8 Draw neat and labelled diagrams.
