1. Living World and Classification of Microbes

General Science Solutions Solutions for Class 8 Science Chapter 1 – Living World And Classification Of Microbes

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Q.1. Fill in the blank and rewrite the completed statements 9

1 In fungi, the cell wall is made up of tough and complex sugar called …………….

Ans In fungi, the cell wall is made up of tough and complex sugar called chitin.

2. reproduce sexually and asexually by cell division or by budding.

Ans Fungi reproduce sexually and asexually by cell division or by budding.

3. All types of bacteria and blue green algae are included in the kingdom …………….

Ans All types of bacteria and blue green algae are included in the kingdom monera.

4. Photosynthesis is carried out with the help of present in the cell.

Ans Photosynthesis is carried out with the help of chloroplast present in the cell.

5. The process of dividing living organism into groups and subgroups is called classification.

Ans The process of dividing living organisms into groups and subgroups is called biological classification.

6. are considered as organisms at the edge of living and nonliving.

Ans Viruses are considered as organisms at the edge of living and nonliving.

7. are found on decaying organic matter and dead bodies of plants and animals.

Ans Fungi are found on decaying organic matter and dead bodies of plants and animals.

8. Protozoans are unicellular organisms with cell.

Ans Protozoans are unicellular organisms with eukaryotic cell.

9. Bacteria reproduce by …………….

Ans Bacteria reproduce by simple binary fission.

Q 2. Find co-related terms 8

  1. Bacteria : Kingdom Monera : : Protozoa : ……………

Ans Bacteria : Kingdom Monera : : Protozoa : Kingdom Protista

2. Kingdom Monera : unicellular : : multicellular

Ans Kingdom Monera : unicellular : : Kindgom Fungi, Kingdom Plantae, Kingdom Animalia : multicellular

3. Human: Polio virus : : Plants: ……………

Ans Human: Polio virus : : Plants : Wilt virus, Tobacco mosaic virus

4. Euglena : Autotrophs : : Paramoecium : ……………

Ans Euglena : Autotrophs : : Paramoecium : Heterotrophs

5. Plasmodium vivax : Malaria : : Entamoeba histolytica : ……………

Ans Plasmodium vivax : Malaria : : Entamoeba histolytica : Amoebiasis

6. Eukaryotic : Protozoa : : Prokaryotic : ……………

Ans Eukaryotic : Protozoa : : Prokaryotic : Bacteria

7. Kopland : four kingdom classification : : five kingdom classification

Ans Kopland : four kingdom classification : : Whittaker : five kingdom classification.

8. Mushroom : Fungi : : Chlamydomonas : ……………

Ans Mushroom : Fungi : : Chlamydomonas : Algae

Q .3. Extra data 4

1. Algae and Fungi.

Ans:

Algae Fungi
Algae are aquatic, eukaryotic, unicellular, autotrophic organisms. Fungi are eukaryotic, unicellular or multicellular organisms that are found on decaying organic matter and dead bodies of plants and animals.

2. Kingdom Monera and Kingdom Protista.

Ans

Kingdom Monera Kingdom Protista
All organisms in kingdom Monera are unicellular.

These are prokaryotic cells without distinct nucleus or cell organelles.

Protista are single celled organism.

These are eukaryotic cells with well-defined nucleus enclosed in a nuclear membrane.

3. Bacteria and Viruses.

Ans:

Bacteria Viruses
Bacteria are prokaryotic, unicellular, independent or parasitic organisms. Sometimes many bacteria together form colonies.
Viruses are extremely minute and 10 to 100 times smaller than bacteria. They are found in form of independent particles which survive only in plant or animal cells.

4. Prokaryotes and Eukaryotes.

Ans:

Prokaryotes Eukaryotes
Prokaryotes are single cell. They are Eukaryotes are multicellular. They are comparatively
smaller in size ranging from 1-10µm with no larger in size than prokaryotes and have distinct nucleus
distinct nucleus or cell organelles. and membrane bound cell organelles.

Q 4.Match the pair 5

1 Find out my partner.

Column – A Column – B
i. Autotrophs a. Amoeba
ii. Heterotrophs b. Aspergillus
iii. Saprotrophs c. Euglena

Ans:

i. Autotrophs Euglena
ii. Heterotrophs Amoeba
iii. Saprotrophs Aspergillus

2. Find out my partner.

Column – A Column – B
i. Kingdom Monera a. Penicillium
ii. Kingdom Protista b. Vibrio choleri
iii. Kingdom Fungi c. Volvox
d. Chlorella

Ans:

i. Kingdom Monera Vibrio choleri
ii. Kingdom Protista Volvox
iii. Kingdom Fungi Penicillium

3. Find out my partner.

Column – A Column – B
i. Fungi a. Chlorella
ii. Protozoa b. Bacteriophage
iii. Virus c. Candida
iv. Algae d. Amoeba
v. Bacteria e. Prokaryotic

Ans:

i. Fungi Candida
ii. Protozoa Amoeba
iii. Virus Bacteriophage
iv. Algae Chlorella
v. Bacteria Prokaryotic

5. Find out my partner.

Column – A Column – B
i. Cattle a. Measles
ii. Human b. Wilt virus
iii. Plants c. Picorna virus

Ans

i. Cattle Picorna virus
ii. Human Measles
iii. Plants Wilt virus

6. Find out my partner.:

Column – A Column – B
i. Eukaryotes a. Algae
ii. Prokaryotes b. Virus
c. Bacteria

Ans

i. Eukaryotes Algae
ii. Prokaryotes Bacteria

Q. 5. State True or False 20

1 Organ of locomotion in amoeba is pseudopodia.

Ans True – Organ of locomotion in amoeba is pseudopodia.

2. Picorna virus affects cattle.

Ans True – Picorna virus affects cattle.

3. All type of bacteria and blue green algae are included in the kingdom Protista.

Ans False – All types of bacteria and blue green algae are included in the kingdom Monera.

4. Bacteria reproduce by simple binary fission.

Ans True – Bacteria reproduce by simple binary fission.

5. Viruses cause many diseases to plants and animals.

Ans True – Viruses cause many diseases to plants and animals.

6. Tomato wilt is a viral disease.

Ans True – Tomato wilt is a viral disease.

7. National Institute of Virology is involved in research on bacteria.

Ans False – National Institute of Virology is involved in research on viruses.

8.  Lactobacilli are harmful bacteria.

Ans False – Lactobacilli are useful bacteria because they are found in curd or buttermilk.

9.  Fungi are prokaryotes.

Ans False – Fungi are eukaryotes.

10 Protozoa has hair like cilia or whip like flagella for locomotion.

Ans True – Protozoa has hair like cilia or whip like flagella for locomotion.

11 Viruses cause many diseases to plants and animals. Cattle are affected by Wilt virus.

Ans False – Cattle are affected by Wilt virus.

12. Saprotrophs feed upon decaying organic matter.

Ans True – Saprotrophs feed upon decaying organic matter.

14. Viruses cause many diseases to plants and animals. AIDS is a diseases caused by virus in humans.

Ans True – AIDS is a diseases caused by virus in humans.

15. Viruses survive only in living plant or animal cells.

Ans True – Viruses survive only in living plant or animal cells.

16 .Viruses cause many diseases to plants and animals. Picorna virus affects plants.

Ans True – Picorna virus affects plants.

17. Cell wall of fungi is made of chitin.

Ans True – Cell wall of fungi is made of chitin.

18. Fungi carry out photosynthesis with the help of chloroplast present in the cell.

Ans False – Algae carry out photosynthesis with the help of chloroplast present in the cell.

19. Viruses cause many diseases to plants and animals.

Ans: True

20 Polio is a disease caused by bacteria in humans.

Ans False – Polio is a disease caused by bacteria in humans.

21.Whittaker divided living organisms into four groups.

Ans False – Whittaker divided living organisms into five groups.

22. Viruses cause many diseases to plants and animals. Viruses attack bacteria.

Ans True – Viruses attack bacteria.

Q 6. Name the following 17

1    Who am I ?

I am green, but don’t have organs.

Ans Algae

2. Any two microorganisms belonging to kingdom Monera.

Ans Salmonella typhi, Clostridium titani, Streptococcus pneumonia, etc.

3. A type of virus that attack bacteria.

Ans Bacteriophage

4. Who am I ? I can produce my replica.

Ans Virus

5. The process of dividing living organism into groups and subgroups.

Ans Biological classification

6. Organisms that feed upon decaying organic matter.

Ans Saprotrophs

7. Who am I ?

I live on decaying organic matter.

Ans Fungus

8. American ecologist who divided living organisms into five groups.

Ans Robert Harding Whittaker

9. Who am I ?

I don’t have true nucleus, cell organelles or plasma membrane.

Ans Prokaryote

10 .Institute in Pune involved in research on viruses.

Ans National Institute of Virology

11. The kingdom that includes all types of bacteria and blue green algae.

Ans Kingdom Monera

12. Any two autotrophic protozoans.

Ans Euglena, Volvox

13. Any two heterotrophic protozoans.

Ans Amoeba, Paramoecium

14. Protozoan that causes malaria.

Ans Plasmodium vivax.

15. Complex sugar that makes the fungal cell wall.

Ans Chitin

16. Who am I ?

I have nucleus and membrane bound organelles.

Ans Eukaryote

17. Who am I ? I reproduce mainly by cell division.

Ans Bacteria

Q 7. Answer in one sentence 5

1. Which living organisms are included in the Kingdom Monera?

Ans All types of bacteria and blue green algae are included in the kingdom Monera.

2. Which level of hierarchy is considered while writing the name in binomial nomenclature?

Ans ‘Genus’ and ‘Species’ is considered while writing the name in binomial nomenclature.

3. Who invented ‘binomial system’ of nomenclature?

Ans ‘Carl Linnaeus’ invented binomial system of nomenclature.

4. Biological classification.

Ans The process of dividing living organism into groups and subgroups is called biological classification.

5. What is the hierarchy of classification of living organisms?

Ans Kingdom → Phylum → Class → Order → Family → Genus → Species

Q 8. Multiple Choice Questions (Activity) 12

1……………… are prokaryotes.

a. Protista  

b. Fungi

c. Algae

d. Bacteria

Ans Option d.

2. Mode of nutrition in fungi ……………

a. Autotrophic

b. Heterotrophic

c. Saprophytic

d. Symbiotic

Ans Option c.

3. Tobacco plant is attacked by …………….

a. tobacco virus

b. tobacco yeast virus

c. tobacco mosaic virus

d. None of these

Ans Option c.

4. Cell wall in fungi are made up of tough and complex sugar called …………….

a. Cytoplasm

b. Citin

c. Chitin

d. Keratin

Ans Option c.

5. carries out the process of photosynthesis.

a. Protista

b. Fungi

c. Algae

d. Bacteria

Ans Option c.

6. Lactobacilli is found in ……………

a. curd

b. buttermilk

c. yogurt

d. all of these

Ans Option d.

7. reproduce by simple binary fission.

a.Protista

b. Fungi

c. Algae

d. Bacteria

Ans Option d.

8. reproduce by budding.

a. Protista

b. Fungi

c. Algae

d. Bacteria

Ans Option b.

9. Kingdom has all bacteria and blue green algae.

Monera b. Protista c. Fungi d. Algae

Ans Option a.

10 …………………..is a saprotroph.

a. Cholera

b. Chlamydomonas

c. Candida

d. Coccus

Ans Option c.

11. Wilt virus is found in …………….

a. potato

b. tomato

c. tobacco

d. none of these

Ans Option b.

12. Mode of nutrition in plants ……………

a. Autotrophic

b. Heterotrophic

c. Saprophytic

d. Symbiotic

Ans Option a.

Q 9.Write Short Notes: 6

1. Bacteria.

Ans i. Bacteria are unicellular, independent/ parasitic organisms. Sometimes many bacteria together form colonies.

ii. Bacterial cell is prokaryotic with cell wall, but distinct nucleus or cell organelles are absent.

iii They reproduce by simple binary fission.

iv. In favorable conditions, bacteria grow vigorously and can double their number in 20 minutes.

2. Protozoa.

Ans i. Protozoans are found in soil, fresh water and sea water. Some are found in the body of other organisms and are pathogenic.

ii. These are unicellular organisms (approximately 200µm in size) with eukaryotic cell.

iii. There is a great variation in cell structure, organs of locomotion and modes of nutrition among protozoans.

iv. These organisms reproduce by simple cell division.

v. Amoeba, Paramoecium, Euglena, etc. are examples of Protozoans.

3. Viruses.

Ans i. Generally, viruses are not considered as living organisms or they are said to be “Organisms at the edge of living and non-living.” They are studied under microbiology.

ii. Viruses are extremely minute i.e. they are 10 to 100 times smaller than bacteria and can be seen only with electron microscope.They are found in the form of independent particles.

iii Virus is a long molecule of DNA (Deoxyribo Nucleic Acid) or RNA (Ribo Nucleic Acid) covered by a protein coat.

iv. Viruses survive only in living plant or animal cells and produce their own proteins with the help of host cell and create their numerous replicas. Then they destroy the host cell and become free. These free viruses again infect new cells. Viruses cause many diseases to plants and animals.

Q 10. Distinguish between 6

1. Algae and Fungi.

Ans

Algae Fungi
Algae are autotrophic organisms i.e. they prepare their own food. Fungi are heterotrophic organisms i.e. they cannot prepare their food.
They are found on decaying organic matter and dead bodies of plants and animals.
They are aquatic
They carry out the process of photosynthesis. They are mostly saprotrophic and hence absorb their food from decaying organic matter.
For example: Chlorella, Chlamydomonas For example: Mushroom, Baker’s yeast, Candida.

2. Prokaryotes and Eukaryotes.

Ans

Prokaryotes Eukaryotes
Prokaryotes are single cell. They are smaller in size ranging from 1-10µm. Eukaryotes are multicellular. They are comparatively larger in size than prokaryotes ranging from 5-100µm.
Prokaryotes don’t have a distinct nucleus and cell organelles are absent. Eukaryotes have a well –defined nucleus and membrane bound organelles.
For example: Bacteria For example: Fungi, Algae

2. Kingdom Monera and Kingdom Protista.

Ans

Kingdom Monera Kingdom Protista
Organisms in kingdom Monera are prokaryotes.
Organisms in kingdom Protista are eukaryotes.
These organisms have cell wall but distinct nucleus or cell organelles are absent.
These organisms have well defined nucleus enclosed in a nuclear membrane.
Kingdom Protista includes Autotrophs like Euglena, Volvox that contain chloroplasts and Heterotrophs like Amoeba, Paramoecium, etc.
Kingdom Monera includes all types of bacteria and blue green algae.

Q. 11.Give scientific reasons 8

1. Fungi are saprophytes.

Ans i. Fungi are heterotrophic organisms i.e. they cannot prepare their own food.

They are found on decaying organic matter and dead bodies of plants and animals.

Most of them are saprotrophs. They absorb their food from decaying organic matter.

Hence, fungi are saprophytes.

2. Viruses are said to be ‘organisms at the edge of living and non-living’.

Ans i. Viruses are extremely small with size ranging from 10 nm to 100 nm and can be seen only with electron microscope.

ii. They are found in the form of independent particles.

iii. Viruses survive only in living plant or animal cells.

iv. They can only replicate themselves by infecting a host cell and therefore cannot reproduce on their own.

v. Viruses show characteristics of living as well as non-living.

vi. Therefore, viruses are said to be ‘organisms at the edge of living and non-living’.

3. Algae are autotrophic in nature.

Ans i. Algae are aquatic, eukaryotic organisms.

ii. Algae may be unicellular or multicellular approximately 10 µm to 100 µm in size.

iii. They carry out the process of photosynthesis with the help of chloroplast present in the cell.

iv. Hence, Algae are autotrophic in nature i.e. they can prepare their own food.

4. Bacteria are prokaryotic in nature.

Ans i. Bacteria are single cell organisms, smaller in size ranging from 1-10µm.

ii. Bacterial cell is prokaryotic with cell wall but distinct nucleus or cell organelles are absent.

iii. All types of bacteria and blue green algae are prokaryotic.

iv. Hence, Bacteria are prokaryotic in nature.

Q 12. Draw / Label the diagram 6

1 Paramoecium

Ans:

2. Bacteriophage

Ans :

3. Different types of bacteria.

Ans :

Q 13. Complete the incomplete diagram 3

1. Complete the five kingdom method of classification using living organisms, prokaryotes, eukaryotes, multicellular, unicellular, protista, animals, plants, fungi.

Ans:

Q 14. Answer the following 39

1. Use Whittaker method to classify bacteria, protozoa, fungi, algae, prokaryotic and eukaryotic microbes.

Ans :

2.

Identify the organism and answer the question given below.

i. Name the kingdom to which this organism belongs.

ii. State any two characteristic of this kingdom.

iii. Give any two examples of organisms from this kingdom.

Ans i. The organism is Bread mold or Mucor : a.It belongs to kingdom Fungi.

b.These are non-green, eukaryotic, heterotrophic organism

Most of them are saprotrophs. They feed upon decaying organic matter.

c.Baker’s yeast, Mushroom, Aspergillus, Pencillium

3. State the characteristics of Algae.

Ans i. Algae are aquatic.

They are approximately 10µm to 100µm in size.

Very few species of algae are unicellular. Most of them are multicellular and visible with naked eyes.

They are eukaryotic, unicellular, autotrophic organisms.

Photosynthesis is carried out with the help of chloroplast present in the cell.

For example: Chlorella, Chlamydomonas.

4. Explain the nutrition in fungi.

Ans i. Fungi are non-green and eukaryotic in nature.

They are heterotrophic organisms i.e. they cannot prepare their own food.

They are found on decaying organic matter and dead bodies of plants and animals.

Fungi shows saprophytic mode of nutrition i.e. they derive nutrition from dead organisms.

For example: Mushrooms grow on decaying organic matter.

5. What are the characteristics of kingdom Fungi?

Ans i. Fungi are non-green, eukaryotic, heterotrophic organisms.

Most of them are saprotrophs. They feed upon decaying organic matter.

Their cell wall is made up of tough and complex sugar called ‘Chitin’.

Some fungi are thread like and many nuclei are present in the cytoplasm.

Examples: Baker’s yeast, Aspergillus, Penicillium, Mushrooms.

6. Identify the living organisms on the basis of following features.

Can be seen only through electron microscope and shows characteristics of living as well as non-living.

Eukaryotic, aquatic and contain chloroplast.

Microscopic, unicellular, Prokaryotic.

Microscopic, unicellular, eukaryotic organisms having flagella.

Unicellular or Multicellular organisms that grow on decaying matter.

Ans i. Virus

Algae

Bacteria

Protozoa

Fungi

7. Write the characteristics of viruses.

Ans i. Viruses are extremely small with size ranging from 10 nm to 100 nm and can be seen only with electron microscope.

They are found in the form of independent particles.

Virus is a long molecule of DNA (Deoxyribo Nuclei Acid) or RNA (Ribo Nucleic Acid) covered by a protein coat.

Viruses survive only in living plant or animal cells and produce their own proteins with the help of host cell and create their numerous replica.

They then destroy the host cell and become free. These free viruses again infect new cells.

Viruses can cause many diseases to plant and animals.

8. State the demerits of Whittaker five kingdom classification.

Ans i. Viruses are not classified properly. There is no space for viruses in five kingdom classification.

Unicellular algae are kept in kingdom Protista, whereas algae like multicellular organisms are kept in kingdom Plantae. But similar organisms must be put together.

The kingdom Protista is not classified properly as it contained different organisms with and without cell wall.

Kingdom Monera and Protista include diverse, heterogeneous form of life. In both kingdoms there are phototrophic as well as heterotrophic organisms.

9. Arrange the following in ascending order of size. (Bacteria, Fungi, Viruses, Algae)

Ans:

10 .State the merits of Whittaker’s method of classification.

Ans i. R.H. Whittaker proposed a five kingdom classification. The kingdoms were named as Monera, Protista, Fungi, Plantae and Animalia.

The merits of this classification are:

The main criteria used by Whittaker included cell structure, mode of nutrition, thallus organization, reproduction and phylogenetic relationship.

Unicellular and Multicellular organisms were grouped separately.

All prokaryotic organisms were grouped together under kingdom Monera and the unicellular eukaryotic organisms were placed in kingdom Protista.

All bacteria are included in kingdom Monera.

Autotrophs and Heterotrophs were placed separately.

11. What are the characteristics of kingdom Protista?

Ans i. Protista are single celled organisms with well-defined nucleus enclosed in a nuclear membrane.

They have pseudopodia or hair like cilia or whip like flagella for locomotion.

Some are Autotrophs – for example-Euglena, Volvox contain chloroplast.

Some are Heterotrophs – for example-Amoeba, Paramoecium

12. Identify the organism and name it.

1.       2.                              3.

Ans

i. Coccus v. Spirillum
ii. Cocco-bacillus vi. Paramoecium
iii. Bacillus vii. Chlorella
iv. Vibrio

13. Which living organisms are included in the kingdom monera?

Ans i.They reproduce by simple binary fission.

ii. Streptococcus pneumoniae, Clostridium titani, Treponema pallidum, Vibrio cholerae, Legionella pneumophila, Salmonella typhi, Clostridium botulinum, Staphylococcus aureus, etc.

Q 15. Read the given paragraph and answer questions based on it 10

1. Nomenclature is the system of scientific naming of living beings so that they can be uniformly identified all over the world. The system of scientific naming was introduced by Carolus Linnaeus. The name of genus begins with a capital letter. The name of species begins with a small letter. When printed, the scientific name is typed in italics. When written by hand, the genus name and species names have to be underlined.

i.What do you understand by nomenclature?

Ii.Who introduced this system?

Iii.How is the scientific name mentioned when it is printed?

Iv. Give any one scientific name of bacteria that you have studied.

Ans i. Nomenclature is the system of scientific naming of living beings so that they can be uniformly identified all over the world.

This system was introduced by Carolus Linnaeus.

The scientific name is typed in italics when it is printed.

Salmonella typhi, Staphylococcus auresus, etc.

2. Prepare a temporary mount of one drop of pond water on a glass slide. Observe it under low power of microscope. Some motile microbes with irregular shape are observed. These are amoeba.

i. Name the kingdom to which Amoeba belongs?

ii .Is it unicellular or multicellular organism?

iii. How does Amoeba bring about its locomotion?

iv. State any one characteristic of this kingdom.

v. Name any two organisms from this kingdom.

Ans i. Amoeba belongs to the kingdom Protista.

ii. Amoeba is unicellular organism.

iii . Amoeba brings about locomotion with the help of pseudopodia.

iv.  Protista are single celled organisms with well-defined nucleus enclosed in a nuclear membrane.

v. Euglena, Paramoecium, Volvox, etc.

Q 16. Answer the following in detail :5

 1. Explain the criteria followed by Whittaker for his five kingdom classification.

Ans i. Whittaker divided living organisms into 5 groups by considering the following criteria.

i. Complexity of the cell structure: Prokaryotes and Eukaryotes.

ii. Complexity of organisms: Unicellular or Multicellular.

iii. Mode of nutrition:

a. Plants-Autotrophic-Photosynthesis

b. Fungi-Saprophytic-Absorption from dead organisms.

c. Animals-Heterotrophic and Ingestive

iv. Life Style:

a. Plants-Producers

b. Animal-Consumers

c. Fungi-Decomposers

v. Phylogenetic relationship: Prokaryotic to Eukaryotic, unicellular to multicellular.

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