Biological Classification

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Learning Objectives

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Learning Objectives

Discuss the evolution of classification systems over time.
Identify economically important uses of heterotrophic bacteria and archaebacteria.
Describe the nature of cell walls in diatoms.
Explain the significance of 'algal bloom' and 'red-tides'.
Differentiate between viroids and viruses.
Summarize the four major groups of Protozoa.
Identify plants that are partially heterotrophic.
Define the terms phycobiont and mycobiont.
Compare the classes of Kingdom Fungi based on mode of nutrition and reproduction.
Describe the characteristic features of Euglenoids.
Outline the structure and nature of genetic material in viruses and name four common viral diseases.

Revision Notes & Summary

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Chapter 2: Biological Classification

2.1 Kingdom Monera

Definition: Kingdom Monera includes all prokaryotic organisms, primarily bacteria.
Characteristics:
- Most abundant microorganisms.
- Found in diverse habitats, including extreme environments.
- Classified into:
  - Archaebacteria: Live in harsh conditions (e.g., halophiles, thermoacidophiles).
  - Eubacteria: True bacteria with rigid cell walls.
Shapes of Bacteria:
- Coccus (spherical)
- Bacillus (rod-shaped)
- Vibrio (comma-shaped)
- Spirillum (spiral)

2.2 Kingdom Protista

Definition: Includes unicellular eukaryotic organisms.
Major Groups:
- Dinoflagellates: Marine, photosynthetic, can cause red tides.
- Euglenoids: Freshwater, flexible pellicle, photosynthetic but can be heterotrophic.
- Slime Moulds: Saprophytic, form plasmodium under suitable conditions.
- Protozoans: Heterotrophic, divided into four groups:
  - Amoeboid protozoans
  - Flagellated protozoans
  - Ciliated protozoans
  - Sporozoans

2.3 Kingdom Fungi

Definition: Heterotrophic organisms, mostly multicellular (except yeast).
Characteristics:
- Cell walls made of chitin.
- Modes of nutrition: saprophytic, parasitic, or symbiotic.
- Reproduction: vegetative, asexual (spores), and sexual.
Classes:
- Phycomycetes
- Ascomycetes
- Basidiomycetes
- Deuteromycetes

2.4 Kingdom Plantae

Definition: Eukaryotic, chlorophyll-containing organisms (plants).
Characteristics:
- Cell walls made of cellulose.
- Includes algae, bryophytes, pteridophytes, gymnosperms, and angiosperms.
- Exhibits alternation of generations (haploid and diploid phases).
Examples of Partially Heterotrophic Plants:
- Insectivorous plants (e.g., Venus flytrap)
- Parasitic plants (e.g., Cuscuta)

2.5 Kingdom Animalia

Definition: Multicellular, heterotrophic organisms lacking cell walls.
Characteristics:
- Holozoic nutrition (ingestion of food).
- Reproduction primarily sexual.
- Defined growth patterns and locomotion capabilities.

2.6 Viruses, Viroids, Prions, and Lichens

Viruses: Non-cellular, inert outside host cells, cause diseases.
Viroids: Infectious agents smaller than viruses, consist of free RNA.
Prions: Infectious proteins causing neurological diseases.
Lichens: Symbiotic associations between algae (phycobiont) and fungi (mycobiont).

Summary of Biological Classification

Historical Context: Classification has evolved from Aristotle's morphological basis to Linnaeus' two-kingdom system and Whittaker's five-kingdom classification.
Five Kingdoms:
- Monera: Prokaryotic, unicellular.
- Protista: Unicellular eukaryotes.
- Fungi: Heterotrophic, mostly multicellular.
- Plantae: Autotrophic, eukaryotic.
- Animalia: Heterotrophic, multicellular.

Table of Characteristics of the Five Kingdoms

Kingdom	Cell Type	Cell Wall	Nuclear Membrane	Body Organisation	Mode of Nutrition
Monera	Prokaryotic	Noncellulosic	Absent	Cellular	Autotrophic/Heterotrophic
Protista	Eukaryotic	Present in some	Present	Cellular	Autotrophic/Heterotrophic
Fungi	Eukaryotic	Present (Chitin)	Present	Multicellular	Heterotrophic (Saprophytic/Parasitic)
Plantae	Eukaryotic	Present (Cellulose)	Present	Multicellular	Autotrophic (Photosynthetic)
Animalia	Eukaryotic	Absent	Present	Organ system	Heterotrophic (Holozoic)

Exam Tips & Common Mistakes

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Common Mistakes and Exam Tips

Common Pitfalls

Misunderstanding Classification Systems: Students often confuse the different classification systems (e.g., Linnaeus' two-kingdom system vs. Whittaker's five-kingdom system). It's crucial to understand the criteria used in each system.
Overlooking Characteristics of Organisms: Failing to recognize the unique features of each kingdom, such as the cell wall composition in fungi (chitin) versus plants (cellulose).
Ignoring the Importance of Nutrition Modes: Not distinguishing between autotrophic and heterotrophic organisms can lead to confusion, especially in kingdoms like Monera and Fungi.
Confusing Viroids and Viruses: Students may not grasp the differences between viroids (free RNA without a protein coat) and viruses (which have a protein coat).

Tips for Exam Preparation

Review Key Characteristics: Make a list of the defining traits of each kingdom (Monera, Protista, Fungi, Plantae, Animalia) to aid in memorization.
Understand Examples: Familiarize yourself with examples of organisms within each kingdom, such as Euglena in Protista and Penicillium in Fungi.
Practice Diagrams: Be able to label diagrams of organisms, such as the structure of bacteria or the life cycle of fungi, as visual aids can enhance understanding.
Discuss Concepts: Engage in discussions about topics like the nature of viruses and their classification to deepen comprehension.
Utilize Past Papers: Practice with previous exam questions to identify common themes and question formats.

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Practice Test – MCQs, True/False

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Multiple Choice Questions

Presence of chlorophyll

Cell wall made of cellulose

Saprophytic mode of nutrition

Prokaryotic cell type

Correct Answer: C

Solution:

Members of Kingdom Fungi show a great diversity in structures and habitat, and most fungi are saprophytic in their mode of nutrition.

Eukaryotic cell type

Presence of a nuclear membrane

Prokaryotic cell type

Multicellular organization

Correct Answer: C

Solution:

Kingdom Monera is characterized by prokaryotic cell types, meaning they lack a true nucleus and membrane-bound organelles.

Heterotrophic; they decompose organic matter

Photosynthetic autotrophs; they contribute to nitrogen fixation

Chemosynthetic autotrophs; they oxidize sulfur compounds

Parasitic; they depend on host organisms for nutrients

Correct Answer: B

Solution:

Cyanobacteria are photosynthetic autotrophs, similar to green plants, and they play a crucial role in nitrogen fixation, converting atmospheric nitrogen into a form usable by plants.

Viroids

Prions

Lichens

Protozoans

Correct Answer: C

Solution:

Lichens are symbiotic associations between algae (phycobiont) and fungi (mycobiont), where algae prepare food and fungi provide shelter and absorb nutrients.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Animalia

Correct Answer: B

Solution:

Kingdom Protista includes all single-celled eukaryotes, which are primarily aquatic and reproduce both asexually and sexually.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: B

Solution:

Kingdom Protista includes all single-celled eukaryotes, which are primarily aquatic and have a well-defined nucleus.

Mushrooms

Euglena

Mosses

Bacteria

Correct Answer: B

Solution:

Euglena is a member of Kingdom Protista, which includes single-celled eukaryotes.

They can survive in extreme conditions.

They have a different cell wall structure compared to other bacteria.

They are eukaryotic.

They include methanogens found in the guts of ruminants.

Correct Answer: C

Solution:

Archaebacteria are prokaryotic, not eukaryotic. They are known for surviving in extreme environments and have a unique cell wall structure.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Animalia

Correct Answer: A

Solution:

Kingdom Monera includes organisms that can be autotrophic or heterotrophic in their mode of nutrition.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: B

Solution:

Kingdom Protista includes all single-celled eukaryotes, which have a well-defined nucleus.

Euglenoids

Eubacteria

Dinoflagellates

Slime moulds

Correct Answer: B

Solution:

Eubacteria are characterized by the presence of a rigid cell wall, and if motile, a flagellum.

They contain DNA or RNA.

They have a protein coat.

They are composed entirely of protein.

They are visible under a light microscope.

Correct Answer: C

Solution:

Prions are infectious agents composed entirely of abnormally folded proteins, lacking nucleic acids such as DNA or RNA.

Prions are viral agents that cause neurological diseases.

Prions are abnormally folded proteins that cause diseases like BSE and CJD.

Prions are bacterial agents causing diseases in cattle.

Prions are nucleic acids that cause plant diseases.

Correct Answer: B

Solution:

Prions are infectious agents composed of abnormally folded proteins, which are known to cause neurological diseases such as bovine spongiform encephalopathy (BSE) in cattle and Creutzfeldt-Jacob disease (CJD) in humans.

Autotrophic

Heterotrophic, primarily saprophytic

Photosynthetic

Chemosynthetic

Correct Answer: B

Solution:

Members of Kingdom Fungi are primarily heterotrophic and obtain nutrients through saprophytic or parasitic modes.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: B

Solution:

Kingdom Protista includes all single-celled eukaryotes such as Chrysophytes, Dinoflagellates, Euglenoids, Slime-moulds, and Protozoans.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: C

Solution:

Kingdom Fungi includes organisms that are primarily saprophytic, meaning they feed on decaying organic matter.

Cellulosic

Chitinous

Silica embedded

Absent

Correct Answer: C

Solution:

Diatoms have cell walls that form two thin overlapping shells, which fit together as in a soap box. The walls are embedded with silica and thus are indestructible.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: B

Solution:

Kingdom Protista includes all single-celled eukaryotes such as Chrysophytes, Dinoflagellates, Euglenoids, Slime-moulds, and Protozoans.

Cellulose

Chitin

Peptidoglycan

Silica

Correct Answer: B

Solution:

The cell wall of fungi is primarily composed of chitin.

Presence of flagella

Cell walls embedded with silica

Lack of a nuclear membrane

Ability to fix nitrogen

Correct Answer: B

Solution:

Diatoms have cell walls embedded with silica, making them indestructible and a major component of diatomaceous earth.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: B

Solution:

Kingdom Protista includes all single-celled eukaryotes such as Chrysophytes, Dinoflagellates, Euglenoids, Slime-moulds, and Protozoans. These organisms have a defined nucleus and other membrane-bound organelles, distinguishing them from the prokaryotic Monera.

They form a multicellular fruiting body called a plasmodium.

They have a rigid cell wall made of cellulose.

They reproduce exclusively through binary fission.

They are obligate parasites.

Correct Answer: A

Solution:

Slime moulds form a multicellular aggregation called a plasmodium during their life cycle, which can spread over several feet and differentiate into fruiting bodies under unfavorable conditions.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: C

Solution:

Kingdom Fungi includes organisms that are primarily decomposers. They have a cell wall made of chitin and show a great diversity in structures and habitat.

Protozoans

Lichens

Euglenoids

Dinoflagellates

Correct Answer: B

Solution:

Lichens are symbiotic associations between algae (phycobiont) and fungi (mycobiont). The algae are photosynthetic, providing food, while the fungi are heterotrophic, providing shelter and absorbing nutrients.

They have a cell wall made of cellulose.

They can survive in extreme environmental conditions.

They are all photosynthetic.

They reproduce only sexually.

Correct Answer: B

Solution:

Archaebacteria are known for their ability to survive in extreme conditions, such as high salinity, temperature, and acidity, due to their unique cell wall structure.

Protists reproduce only asexually.

Protists reproduce both asexually and sexually.

Protists reproduce only through binary fission.

Protists reproduce by forming spores only.

Correct Answer: B

Solution:

Protists reproduce both asexually and sexually, involving processes like cell fusion and zygote formation.

Tuberculosis

Mad cow disease

Influenza

Malaria

Correct Answer: B

Solution:

Mad cow disease, also known as bovine spongiform encephalopathy, is caused by prions.

They have a protein coat.

They consist of abnormally folded protein.

They contain RNA as genetic material.

They are obligate parasites.

Correct Answer: B

Solution:

Prions are infectious agents consisting of abnormally folded protein, similar in size to viruses, and are known to cause diseases like mad cow disease.

Presence of a cellulose cell wall

Ability to photosynthesize and become heterotrophic

Formation of spores during unfavorable conditions

Presence of two equal-length flagella

Correct Answer: B

Solution:

Euglenoids have a flexible pellicle instead of a cell wall and can photosynthesize in the presence of sunlight. In the absence of sunlight, they can switch to heterotrophic nutrition, allowing them to adapt to different environments.

Presence of cellulose

Presence of chitin

Presence of silica

Absence of a cell wall

Correct Answer: C

Solution:

Diatoms have cell walls embedded with silica, making them indestructible and contributing to the formation of diatomaceous earth, which is used in polishing and filtration.

Decomposers

Primary producers

Parasites

Symbionts

Correct Answer: B

Solution:

Diatoms are primary producers in marine environments. They are photosynthetic and form the base of the aquatic food chain.

Dinoflagellates

Euglenoids

Diatoms

Protozoans

Correct Answer: C

Solution:

Diatoms have silica-embedded cell walls and are known as the chief producers in the oceans due to their photosynthetic capability.

They reproduce primarily through binary fission.

They form fruiting bodies that release spores under adverse conditions.

They reproduce through budding.

They rely on sexual reproduction exclusively.

Correct Answer: B

Solution:

Slime moulds are saprophytic protists that form a plasmodium. Under unfavorable conditions, they differentiate to form fruiting bodies that release spores, which are resistant and can survive for long periods.

Mushrooms

Yeasts

Mosses

Molds

Correct Answer: C

Solution:

Mosses are non-vascular plants and belong to Kingdom Plantae, not Fungi.

Cyanobacteria; the cyanobacteria provide minerals while fungi perform photosynthesis

Green algae; the algae provide food through photosynthesis while fungi offer protection and nutrients

Dinoflagellates; they provide light through bioluminescence while fungi offer structural support

Protozoans; they provide movement while fungi absorb nutrients

Correct Answer: B

Solution:

Lichens are symbiotic associations between algae (phycobiont) and fungi (mycobiont). The algae perform photosynthesis to provide food, while the fungi offer protection and absorb mineral nutrients and water.

Presence of a nuclear membrane

Cell wall composed of chitin

Photosynthetic mode of nutrition

Multicellular organization

Correct Answer: B

Solution:

Kingdom Fungi is characterized by having a cell wall made of chitin, which is distinct from the cellulose cell walls of plants. This feature sets them apart from other kingdoms in Whittaker's classification.

Diatoms

Dinoflagellates

Euglenoids

Slime moulds

Correct Answer: C

Solution:

Euglenoids have a protein-rich layer called pellicle instead of a cell wall, which provides flexibility.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Animalia

Correct Answer: D

Solution:

Kingdom Animalia includes heterotrophic organisms that lack a cell wall.

They have a cell wall made of cellulose.

They are found in extreme environments.

They are eukaryotic.

They are primarily autotrophic.

Correct Answer: B

Solution:

Archaebacteria are special since they live in some of the most harsh habitats such as extreme salty areas, hot springs, and marshy areas.

They are primarily aquatic.

They are photosynthetic.

They form a plasmodium under suitable conditions.

They have a pellicle instead of a cell wall.

Correct Answer: C

Solution:

Slime moulds are saprophytic protists that form a plasmodium, which can grow and spread over several feet under suitable conditions.

Their cell walls are composed of silica, making them indestructible.

They possess a protein-rich layer called pellicle instead of a cell wall.

They have a cellulose-based cell wall with stiff plates.

They can fix atmospheric nitrogen in specialized cells called heterocysts.

Correct Answer: A

Solution:

Diatoms have cell walls composed of silica, which makes them indestructible and allows them to leave behind large deposits known as diatomaceous earth, playing a crucial role as primary producers in aquatic ecosystems.

Kingdom Monera

Kingdom Protista

Kingdom Plantae

Kingdom Animalia

Correct Answer: C

Solution:

Kingdom Plantae includes all eukaryotic chlorophyll-containing organisms that are primarily autotrophic and have a cell wall made of cellulose.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: B

Solution:

Kingdom Protista includes all single-celled eukaryotes such as Chrysophytes, Dinoflagellates, Euglenoids, Slime-moulds, and Protozoans. Members of Protista are primarily aquatic and can have both autotrophic and heterotrophic modes of nutrition.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Animalia

Correct Answer: B

Solution:

Kingdom Protista includes organisms that can be autotrophic (photosynthetic) and heterotrophic. For example, euglenoids can photosynthesize in the presence of light and become heterotrophic in its absence.

They reproduce only sexually.

They reproduce by binary fission.

They reproduce by budding.

They reproduce by spore formation only.

Correct Answer: B

Solution:

Bacteria primarily reproduce by binary fission, a form of asexual reproduction.

They have a protein coat.

They contain both RNA and DNA.

They are smaller than viruses and lack a protein coat.

They are larger than bacteria.

Correct Answer: C

Solution:

Viroids are smaller than viruses and consist of free RNA without a protein coat.

Their cell walls are made of cellulose, which allows them to float.

They have chlorophyll a, enabling photosynthesis.

Their cell walls are embedded with silica, making them indestructible.

They possess flagella for movement towards light.

Correct Answer: C

Solution:

Diatoms have cell walls embedded with silica, which makes them indestructible and allows them to accumulate as diatomaceous earth. This feature, combined with their photosynthetic ability, makes them significant primary producers in marine environments.

They are composed of cellulose.

They are embedded with silica.

They are made of chitin.

They lack a cell wall.

Correct Answer: B

Solution:

Diatoms have cell walls embedded with silica, making them indestructible and contributing to the formation of diatomaceous earth.

Monera

Protista

Fungi

Animalia

Correct Answer: B

Solution:

Euglenoids, which are part of Kingdom Protista, have a pellicle instead of a cell wall.

Chitin

Cellulose

Silica

Peptidoglycan

Correct Answer: C

Solution:

Diatoms have cell walls embedded with silica, making them indestructible.

They are primary consumers in aquatic ecosystems.

They are decomposers that break down organic matter.

They are photosynthetic autotrophs that contribute to nitrogen fixation.

They are parasitic organisms that feed on host plants.

Correct Answer: C

Solution:

Cyanobacteria, also known as blue-green algae, are photosynthetic autotrophs that can fix atmospheric nitrogen in specialized cells called heterocysts.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: C

Solution:

Kingdom Fungi includes organisms that are primarily saprophytic in their mode of nutrition.

Eubacteria

Archaebacteria

Cyanobacteria

Mycoplasma

Correct Answer: B

Solution:

Archaebacteria are known for their ability to survive in extreme conditions such as high salinity (halophiles), high temperature (thermoacidophiles), and anaerobic environments (methanogens).

Presence of a cell wall

Heterotrophic mode of nutrition

Multicellular organization without a cell wall

Photosynthetic autotrophy

Correct Answer: C

Solution:

Kingdom Animalia is characterized by multicellular organisms that lack a cell wall, distinguishing them from other kingdoms.

Photosynthetic

Heterotrophic

Chemosynthetic

Autotrophic

Correct Answer: B

Solution:

Organisms in Kingdom Fungi are primarily heterotrophic, obtaining nutrients by absorbing organic material.

They contain RNA as genetic material

They lack a protein coat

They are composed of abnormally folded proteins

They infect only plant cells

Correct Answer: C

Solution:

Prions are infectious agents composed of abnormally folded proteins, unlike viruses which contain nucleic acids (RNA or DNA) and have a protein coat. Prions are known for causing neurological diseases such as mad cow disease.

Presence of a nuclear membrane

Prokaryotic cell type

Multicellular body organization

Photosynthetic mode of nutrition

Correct Answer: B

Solution:

Kingdom Monera is unique in that it consists of prokaryotic organisms, which lack a true nuclear membrane, unlike the eukaryotic organisms in other kingdoms.

Monera

Protista

Fungi

Animalia

Correct Answer: C

Solution:

Kingdom Fungi includes organisms that are primarily saprophytic, obtaining nutrients by decomposing organic matter.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: C

Solution:

Kingdom Fungi is characterized by organisms having a cell wall made of chitin.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: C

Solution:

Kingdom Fungi is characterized by organisms that have a cell wall made of chitin.

Heterotrophic

Saprophytic

Autotrophic

Parasitic

Correct Answer: C

Solution:

The primary mode of nutrition for organisms in Kingdom Plantae is autotrophic, as they are eukaryotic chlorophyll-containing organisms.

Diatoms

Dinoflagellates

Euglenoids

Slime moulds

Correct Answer: C

Solution:

Euglenoids have a protein-rich layer called a pellicle instead of a cell wall, which provides flexibility to their structure.

It provides food through photosynthesis.

It provides shelter and absorbs nutrients.

It fixes atmospheric nitrogen.

It is responsible for reproduction.

Correct Answer: B

Solution:

In lichens, the mycobiont (fungal component) provides shelter and absorbs mineral nutrients and water for the algal partner.

Primary producers

Decomposers

Nitrogen fixers

Pathogens only

Correct Answer: B

Solution:

Fungi primarily act as decomposers in the ecosystem, breaking down dead organic matter and recycling nutrients, although some can also be pathogenic.

They have chlorophyll a similar to green plants and are photosynthetic.

They are capable of surviving in the absence of oxygen.

They have a protein-rich layer called pellicle.

They lack a cell wall entirely.

Correct Answer: A

Solution:

Cyanobacteria, also known as blue-green algae, possess chlorophyll a similar to green plants and are photosynthetic autotrophs, distinguishing them from other eubacteria.

Kingdom Monera

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Correct Answer: A

Solution:

Kingdom Monera includes archaebacteria, which are known for their ability to survive in extreme environments such as hot springs and salty areas.

Euglena

Amoeba

Paramecium

Plasmodium

Correct Answer: A

Solution:

Euglena, a member of Kingdom Protista, is photosynthetic in sunlight but can also act as a heterotroph by predating on smaller organisms when sunlight is unavailable.

Ascomycetes

Basidiomycetes

Deuteromycetes

Phycomycetes

Correct Answer: C

Solution:

Deuteromycetes are known as 'imperfect fungi' because only their asexual or vegetative phases are known. When their sexual forms are discovered, they are reclassified into Ascomycetes or Basidiomycetes.

Dinoflagellates

Euglenoids

Slime moulds

Protozoans

Correct Answer: B

Solution:

Euglenoids have a protein-rich layer called pellicle which makes their body flexible, instead of a cell wall.

Presence of cellulose

Presence of chitin

Presence of silica

Absence of a cell wall

Correct Answer: C

Solution:

Diatoms have cell walls that are embedded with silica, which is a unique feature distinguishing them from other protists. This silica composition makes their cell walls indestructible.

Euglenoids

Dinoflagellates

Slime moulds

Protozoans

Correct Answer: B

Solution:

Red dinoflagellates, such as Gonyaulax, can multiply rapidly and cause red tides.

True or False

Correct Answer: False

Solution:

In the five kingdom classification, bacteria are included in Kingdom Monera.

Correct Answer: True

Solution:

Prions are known to cause diseases like mad cow disease and consist of abnormally folded proteins.

Correct Answer: True

Solution:

Viroids are infectious agents that are smaller than viruses and consist solely of RNA without a protein coat.

Correct Answer: True

Solution:

R.H. Whittaker proposed the Five Kingdom Classification which includes Monera, Protista, Fungi, Plantae, and Animalia.

Correct Answer: False

Solution:

Slime moulds are classified under Kingdom Protista, not Fungi.

Correct Answer: True

Solution:

Whittaker's Five Kingdom Classification divides organisms into Monera, Protista, Fungi, Plantae, and Animalia based on criteria such as cell structure and mode of nutrition.

Correct Answer: True

Solution:

Red dinoflagellates, such as Gonyaulax, can multiply rapidly, causing red tides.

Correct Answer: False

Solution:

Kingdom Protista includes all single-celled eukaryotes, which are primarily unicellular organisms.

Correct Answer: False

Solution:

Linnaeus' Two Kingdom Classification did not distinguish between unicellular and multicellular organisms.

Correct Answer: True

Solution:

Prions are infectious agents made of abnormally folded proteins, similar in size to viruses, and cause diseases like mad cow disease.

Correct Answer: True

Solution:

Euglenoids are capable of photosynthesis in sunlight but can switch to heterotrophy when deprived of light.

Correct Answer: True

Solution:

Diatoms have cell walls embedded with silica, which makes them indestructible and forms diatomaceous earth.

Correct Answer: True

Solution:

Bacteria exhibit metabolic diversity and can be autotrophic (synthesizing their own food) or heterotrophic (depending on other organisms for food).

Correct Answer: True

Solution:

Aristotle classified plants into trees, shrubs, and herbs and animals into those with red blood and those without.

Correct Answer: False

Solution:

Linnaeus' two kingdom system did not distinguish between eukaryotes and prokaryotes.

Correct Answer: False

Solution:

Fungi are primarily heterotrophic organisms, obtaining nutrients by absorbing organic matter from their environment.

Correct Answer: True

Solution:

Archaebacteria have a different cell wall structure that allows them to survive in harsh environments like extreme salty areas, hot springs, and marshy areas.

Correct Answer: True

Solution:

Archaebacteria have a different cell wall structure that allows them to survive in harsh environments such as extreme salty areas, hot springs, and marshy areas.

Correct Answer: True

Solution:

Diatoms have cell walls that form two thin overlapping shells embedded with silica, making them indestructible.

Correct Answer: False

Solution:

Viroids are composed of free RNA and lack the protein coat that is found in viruses.

Correct Answer: False

Solution:

Lichens are a symbiotic association between algae (phycobiont) and fungi (mycobiont), not bacteria.

Correct Answer: False

Solution:

The Kingdom Protista includes all single-celled eukaryotes, not multicellular organisms.

Correct Answer: False

Solution:

Euglenoids do not have a cell wall; instead, they have a protein-rich layer called a pellicle, which provides flexibility.

Correct Answer: False

Solution:

Viroids are smaller than viruses and lack the protein coat that is found in viruses.

Correct Answer: False

Solution:

Kingdom Monera consists of prokaryotic organisms, not eukaryotic.

Correct Answer: False

Solution:

Euglenoids do not have a cellulose cell wall; instead, they have a protein-rich layer called a pellicle.

Correct Answer: True

Solution:

Aristotle used simple morphological characters to classify plants and animals, making him one of the earliest to attempt a scientific classification.

Correct Answer: False

Solution:

Diatoms have cell walls embedded with silica, not cellulose, making them indestructible.

Correct Answer: False

Solution:

Most members of Kingdom Fungi are saprophytic, which means they are heterotrophic, not autotrophic.

Correct Answer: False

Solution:

While some bacteria are autotrophic, the vast majority are heterotrophs, relying on other organisms or dead organic matter for food.

Correct Answer: False

Solution:

Diatoms have cell walls embedded with silica, not cellulose.

Correct Answer: True

Solution:

Kingdom Monera is characterized by prokaryotic cell types, which lack a defined nucleus.

Correct Answer: False

Solution:

Linnaeus' two kingdom classification system did not distinguish between unicellular and multicellular organisms.

Correct Answer: False

Solution:

In the five kingdom classification, the Kingdom Monera includes prokaryotic organisms, while the other four kingdoms (Protista, Fungi, Plantae, and Animalia) include eukaryotic organisms.

Correct Answer: True

Solution:

Viroids are infectious agents that are smaller than viruses and consist of free RNA without a protein coat.

Correct Answer: True

Solution:

Whittaker's Five Kingdom Classification includes Monera, which is characterized by prokaryotic cell types.

Correct Answer: True

Solution:

Euglenoids have a flexible body and can switch between photosynthesis and heterotrophy depending on the availability of sunlight.

Correct Answer: True

Solution:

Euglenoids are photosynthetic in the presence of sunlight but can behave like heterotrophs by preying on other organisms when deprived of sunlight.

Correct Answer: False

Solution:

Viruses contain either RNA or DNA as their genetic material, but not both.

Correct Answer: False

Solution:

Viruses contain either RNA or DNA as their genetic material, but never both.

Correct Answer: True

Solution:

The five kingdom classification considers mode of nutrition and reproduction as criteria for classifying fungi.

Correct Answer: False

Solution:

Lichens are a symbiotic association between algae (phycobiont) and fungi (mycobiont).

Correct Answer: True

Solution:

Lichens are a mutually beneficial association between algae (phycobiont) and fungi (mycobiont), where algae provide food and fungi provide shelter and nutrients.

Correct Answer: False

Solution:

Linnaeus' two kingdom system did not distinguish between eukaryotes and prokaryotes, as it only included Plantae and Animalia.

Biological Classification

Learning Objectives

Learning Objectives

Revision Notes & Summary

Chapter 2: Biological Classification

2.1 Kingdom Monera

2.2 Kingdom Protista

2.3 Kingdom Fungi

2.4 Kingdom Plantae

2.5 Kingdom Animalia

2.6 Viruses, Viroids, Prions, and Lichens

Summary of Biological Classification

Table of Characteristics of the Five Kingdoms

Exam Tips & Common Mistakes

Common Mistakes and Exam Tips

Common Pitfalls

Tips for Exam Preparation

AI Learning Assistant

Practice Test – MCQs, True/False

Multiple Choice Questions

Q1.Which of the following is a characteristic feature of Kingdom Fungi?

Correct Answer: C

Q2.Which of the following is a characteristic feature of Kingdom Monera?

Correct Answer: C

Q3.Which of the following best describes the nutritional mode of cyanobacteria, and what ecological role do they play?

Correct Answer: B

Q4.Which of the following groups of organisms is known for having a symbiotic relationship between an algal and a fungal component?

Correct Answer: C

Q5.Which kingdom includes organisms that are primarily aquatic, have a well-defined nucleus, and reproduce both asexually and sexually?

Correct Answer: B

Q6.Which kingdom includes organisms that are primarily aquatic and have a well-defined nucleus?

Correct Answer: B

Q7.Which of the following organisms can be classified under Kingdom Protista?

Correct Answer: B

Q8.Which of the following is NOT a characteristic of archaebacteria?

Correct Answer: C

Q9.Which of the following kingdoms includes organisms that can be autotrophic or heterotrophic?

Correct Answer: A

Q10.Which kingdom includes organisms that are primarily unicellular and have a well-defined nucleus?

Correct Answer: B

Q11.Which of the following organisms is known for having a rigid cell wall and, if motile, a flagellum?

Correct Answer: B

Q12.Which of the following is a characteristic feature of prions that differentiates them from other infectious agents?

Correct Answer: C

Q13.Which of the following statements correctly describes the role of prions in infectious diseases?

Correct Answer: B

Q14.Which of the following best describes the mode of nutrition in Kingdom Fungi?

Correct Answer: B

Q15.Which of the following kingdoms includes organisms that are primarily unicellular and eukaryotic?

Correct Answer: B

Q16.In the five kingdom classification proposed by Whittaker, which kingdom includes organisms that are primarily saprophytic in their mode of nutrition?

Correct Answer: C

Q17.What type of cell wall do diatoms possess?

Correct Answer: C

Q18.Which of the following kingdoms includes all single-celled eukaryotes?

Correct Answer: B

Q19.What is the main component of the cell wall in fungi?

Correct Answer: B

Q20.Which of the following is a characteristic feature of diatoms?

Correct Answer: B

Q21.In the five kingdom classification proposed by Whittaker, which kingdom includes organisms that are primarily unicellular and eukaryotic?

Correct Answer: B

Q22.Which of the following is a characteristic feature of slime moulds during their life cycle?

Correct Answer: A

Q23.Which kingdom includes organisms that are primarily decomposers and have a cell wall made of chitin?

Correct Answer: C

Q24.Which of the following groups of organisms is known for having a symbiotic relationship between a photosynthetic and a heterotrophic component?

Correct Answer: B

Q25.In the context of biological classification, which of the following statements about archaebacteria is true?

Correct Answer: B

Q26.Which of the following statements is true regarding the reproduction of protists?

Correct Answer: B

Q27.Which of the following diseases is caused by prions?

Correct Answer: B

Q28.Which of the following is a characteristic feature of prions?

Correct Answer: B

Q29.Which of the following is a distinguishing feature of euglenoids that allows them to survive in varying environmental conditions?

Correct Answer: B

Q30.Which of the following is a unique feature of the cell wall in diatoms that contributes to their ecological role?

Correct Answer: C